CME Annual Report 2013-2014 by Faculty of Engineering & Information Sciences

SCHOOL OF CIVIL, MINING & ENVIRONMENTAL ENGINEERING

2013–2014 ANNUAL REPORT

Faculty of Engineering & Information Sciences

TABLE OF CONTENTS MESSAGE FROM HEAD OF SCHOOL PERSONNEL

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Researcher Profiles

EARLY CAREER RESEARCHERS

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Professional Staff Research Students Research Student Profiles

TEACHING AND LEARNING

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Student competitions New subjects and delivery method

RESEARCH

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Research Centres Engineering and Mathematics Education Research Group (EMERG) GeoQuest Geomechanics and Railway Engineering Centre for Infrastructure Protection and Mining and Safety Mining Research Centre

SELECTED RESEARCH PROJECTS

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Publications Selected Awards and Achievements Equipment and Facilities Research Grants

COMMUNICATION Alumni

Plenary, Keynote & Invited Lectures Visitors and Collaboration Seminars Conferences and Workshops

PERFORMANCE INDICATORS

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Research Income Postgraduate Commencement and Completion Data

MESSAGE FROM HEAD OF SCHOOL The School of Civil, Mining and Environmental Engineering (CME) enjoys a world class reputation for excellence in research, innovative approaches to teaching and learning, and laboratories and workshop facilities that are among the best in Australia. The School currently employs twenty full-time academic staff, and has the highest proportion of staff with PhD’s (100%) amongst the top Australian Universities. Currently the school has over 400 undergraduate students and over 70 PhD students with excellent graduate outcomes. All degrees are fully accredited by Engineers Australia and The Australasian Institute of Mining and Metallurgy. The School thrives on the quality of its academic and technical staff who have won numerous teaching, research and general staff awards, and takes great pride in the quality of its graduates. Recent prestigious international awards received by academics include ASCE’s Middlebrooks and Canadian Geotechnical Society’s Robert Quigley awards, CS Desai Medal, and the GN Alexander medal from the Institution of Engineers Australia for outstanding research contributions. Greater interaction with industry colleagues in all disciplinary areas has created synergies with the enviable result of industrybased grants in research through the Australian Research Council (ARC) Projects, the Cooperative Research Centre for Railway Innovation (CRC-Rail) and the Australian Coal Association Research Program (ACARP). The research intensive culture in the School is consistently associated with a strong number of research students (enrolments and completions), an impressive rate of peer-reviewed publications, national and international awards for academic staff in teaching and research, significant infrastructure grants for modernisation of laboratories, and increased participation of international academics in research activities. All of these have contributed towards the reputation of the School as one of the best in the country. While providing an excellent teaching and research environment within the School, the academic staff are also now involved in major consultancies and contract research, including modern design and performance verification of roads and rail tracks, ground improvement of reclaimed land for expansion of ports, development of floodplains, protection of infrastructure from extreme events, innovative composite structures, steel structural design, dam maintenance, waste water treatment and recycling, landslides risk assessment, offshore development and design of marine risers. The School of Civil, Mining and Environmental Engineering is geared to meet not only the future educational challenges for producing the leading graduates in the country, but also to face the dramatically changing industrial trends and environmental changes. I thank all our School’s academic, technical and professional staff, the past and present students and the local community for their concerted efforts in making our School for what it is today. I do hope you enjoy reading about the exciting research and teaching activities and events of the School of Civil, Mining and Environmental Engineering.

Alex Remennikov

School of Civil, Mining Engineering Faculty of Engineering & Information Sciences

PERSONNEL

2 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Position: Professor of Civil Engineering Em: indra@uow.edu.au Tel: +61 2 4221 3046 Research Interests: Ground improvement including sub-surface drainage and soft clay stabilisation, Large scale geotechnical testing and process simulation, Railway foundations, Jointed rock engineering, Geoenvironmental engineering including remediation of acid sulphate soils, Flow through porous and jointed media including dam filters, Dams and embankment engineering, Numerical and analytical modelling and Ground instrumentation.

PROFESSOR TIMOTHY MCCARTHY PhD, MSc, BE (Civil), MIEI Position: Professor of Structural Steel and Design Em: tim_mccarthy@uow.edu.au Tel: +61 2 4221 4591 Research Interests: Ecologically sustainable structural design, Sustainable construction materials, Structural steel design, Mooring design for floating wave energy devices, Engineering Education Research, Building Information Modelling.

PROFESSOR LONG NGHIEM PhD, Master of Education, BE (1st class Honour), Grad Cert in Business Position: Professor Em: longn@uow.edu.au Tel: +61 2 4221 4590 Research Interests: Professor Nghiem is a membrane technologist. His research expertise covers a range of membrane separation processes including pressure driven membrane filtration, forward osmosis, membrane distillation, facilitated transport membrane, membrane electrolysis, and membrane bioreactor. Current research work of his membrane separation laboratory focuses on the development of a membrane-based platform for the recovery of clean water, energy, and nutrients from wastewater.

ASSOCIATE PROFESSOR ERNEST BAAFI PHD, MSc, BSC, ACSM, MAusIMM Position: Mining Engineering Discipline Advisor Em: ebaafi@uow.edu.au Tel: +61 2 4221 3031 Research Interests Geostatistics, Mine system simulation and Operations research methodologies to mine evaluation and design.

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PERSONNEL

PROFESSOR BUDDHIMA INDRARATNA PhD, MSc, DIC, BSc (Hons), FTSE, FAusIMM, FIEAust, FASCE, FGS, CEng, CPEng

ASSOCIATE PROFESSOR WEI DONG GUO PhD, MEng, CPEng, BEng, M.ASCE, MIEAust, M.ISSMGE, M.AGS, MSEAGS

PERSONNEL

Position: Associate Professor in Geotechnical Engineering Em: wdguo@uow.edu.au Tel: +61 2 4221 3036 Research Interests: Theoretical modelling of soil-structural interaction (united analytical model and solutions for beam soil interaction); Offshore foundations (piles, anchored piles, anchors); Special foundations for extreme loading (mono-piles, screw piles, branch piles, etc); Constitutive modelling (granular model) for bonded material (soft rock, flexible pavement, cemented sand, etc), Passive piles and pipelines due to soil movement (excavation, slope, lateral spreading, embankment), and ground improvement (saturated and unsaturated soil, granular modelling).

ASSOCIATE PROFESSOR MUHAMMAD HADI PhD, MSc, BSc (Hons), CPEng, FIEAust, F.SEI, F.ASCE, NPER, M-ACI, IABSE, IIFC Position: Associate Professor Em: mhadi@uow.edu.au Tel: +61 2 4221 4762 Research Interests: Strengthening structures using fibre reinforced polymers, Concrete structures, Optimisation, Neural networks and Pavement.

ASSOCIATE PROFESSOR IAN PORTER PhD, BSc (Eng) Hons Position: Associate Professor Em: iporter@uow.edu.au Tel: +61 2 4221 3451 Research Interests: Rock mechanics and ground control in mining; Mine ventilation and the mine environment; and Systems analysis of longwall mining.

ASSOCIATE PROFESSOR ALEX REMENNIKOV PhD, MEng, BEng, MIEAust, MASCE, CPEng Position: Head of School Em: alexrem@uow.edu.au Tel: +61 2 4221 5574 Research Interests: Behaviour of structures under extreme loading (impact, shock, blast); finite element modelling of structures under impact and blast loads; and dynamics of railway tracks, impulsive loading and response of railway track system and component.

4 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Position: Senior Lecturer in Mining Engineering, Director, Centre of Infrastructure Protection and Mining Safety Em: tren@uow.edu.au Tel: +61 2 4221 4186 Research Interests: Mining Engineering and Safety: coal mine gas, dust and fire control; Computational modelling and Simulation in Mining Engineering.

ASSOCIATE PROFESSOR CHOLACHAT RUJIKIATKAMJORN PhD, MEng, BEng, MIEAust Position: Associate Professor Em: cholacha@uow.edu.au Tel: +61 2 4221 5852 Research Interests: Ground Improvement, Railway Engineering.

ASSOCIATE PROFESSOR (SIVA) MUTTUCUMARU SIVAKUMAR PhD, ME Hons, BSc (Eng) Hons, CPEng, MAWA, FIEAust, Postition: Associate Professor Em: siva@uow.edu.au Tel: +61 2 4221 3055 Research Interests: Sustainable and integrated water resources management, Water quality and ecological modelling of catchments, rivers and lakes, Sustainable design of water and wastewater treatment processes, Solar based membrane processes for water treatment and recycling, Bio-hydrogen and bio-methane production from co-digestion of wastes, Agricultural waste management and resource recovery.

ASSOCIATE PROFESSOR LIP TEH PhD, BE Hons 1 (Civil & Mining), Position: Associate Professor Em: lteh@uow.edu.au Tel: +61 2 4221 3564 Research Interests: Advanced analysis of steel frames, beam finite elements, bolted connections, climate resilient structures, cold-formed steel, frame stability, modular construction, progressive collapse, retrofitting and strengthening of steel structures, storage racks, and sustainable structural design.

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PERSONNEL

ASSOCIATE PROFESSOR TING REN PhD, MMEng, BEng, CPEng, MAusIMM, MIMMM

ASSOCIATE PROFESSOR SHU-QING YANG PhD, M.ASCE, M.IAHR, M.AGU

PERSONNEL

Position: Associate Professor Em: shuqing@uow.edu.au Tel: +61 2 42213070 Research Interests: Fundamental research in Sediment transport, Open channel turbulence, Coastal Engineering, Water resources engineering; Practical research: how to develop clean freshwater from the sea without desalination using strategy of coastal reservoir and its application in China and Australia; how to develop good quality water from a polluted river system using zero energy and zero carbon method and its application in Shanghai.

DR FAISAL I HAI PhD, MSc (Eng), BSc (Eng) Position: Senior Lecturer Em: Faisal@uow.edu.au Tel: +61 2 4221 3054 Research Interests: Dr Haiâ&#x20AC;&#x2122;s broad topics of interest include advanced water and wastewater treatment, environmental biotechnology and hazardous waste management. Building on his vast experience with membrane bioreactor (MBR) technology, Dr Hai continues to carry out exciting research on the application of hybrid physicochemical processes having MBR as the core for the removal of biologically persistent compounds (especially micropollutants) from water and wastewater.

DR MARTIN LIU PhD, MPhil, BEng Position: Senior Lecturer Em: martindl@uow.edu.au Tel: +61 2 4221 3035 Research Interests: Investigating mechanical properties of geo-materials and analysing key parameters. Constitutive modelling of the behaviour of geomaterials. My current focus is on theoretical study of the variation of the mechanical properties of geomaterials with various structures, including understanding the formulation and development of material anisotropy and proposing physical and mathematical models for elastic and plastic deformation.

DR JAN NEMCIK PhD, ME, BSC (ENG) HONS Position: Senior Lecturer Em: jnemcik@uow.edu.au Tel: +61 2 4221 4492 Research Interests: Fracture mechanics in rock - theory and numerical modelling, Geotechnical measurements and instrumentation for underground excavations, Stress distribution and rock failure about underground openings, Numerical modelling of underground excavations, Numerical modelling of the longwall powered supports and their influence on strata behaviour at/ahead of the moving coal mining longwall face and Evaluation of the longwall powered supports and their suitability to mine in variable ground, Rock bolting, This Spray on Liner (TSL) - Research & development.

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Position: Senior Lecturer Em: msheikh@uow.edu.au Tel: +61 2 4221 3009 Research interests: Earthquake engineering, Performance-based seismic design and analyses of structures, Design and analyses of structures under extreme environmental and man-made loads, Application of advanced materials e.g., fibre-reinforced polymer composites in concrete structures, Soil dynamics and soil-structure interactions.

DR J S VINOD PhD, MTech, BTech, MAGS, MAEES, MIGS Position: Senior Lecturer Em: vinod@uow.edu.au Tel: +61 2 4221 4089 Research Interests: DEM modeling of geomaterials, Soil dynamics, Energy geotechnics, Chemical Stabilisation & Ground Improvement technique.

DR TAO YU PhD, BEng, MIIFC Position: Senior Lecturer Em: taoy@uow.edu.au Tel: +61 2 4221 3786 Research Interests: Infrastructure application of FRP composites; Hybrid tubular structures; Rehabilitation of steel and concrete structures; Nonlinear finite element analysis of structures. Memberships & Affiliations - Structural Stability Research Council, American Institute of Steel Construction

MR ERIC LUME BEng (UNSW) Position: Lecturer Em: elume@uow.edu.au Tel: +61 2 4221 3043 Research Interests: Concrete and masonry.

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PERSONNEL

DR NEAZ SHEIKH PhD, MPhil, BSc (Eng),

DR TRUNG NGO PhD (Geotechnical Engineering), MEng, BEng

PERSONNEL

Position: Lecturer at CME Em: trung@uow.edu.au Tel: +61 2 4221 4892 Research Interests: Geotechnical Engineering including ballasted rail tracks and stone columns stabilised soft clay using experimental and numerical methods, Numerical simulation using Discrete Element Method (DEM) for railway ballast, Coupled DEM-Finite Different simulation to model ballasted rail tracks and stone columns.

DR ANA RIBEIRO HEITOR PhD, MEng, LicEng Position: Lecturer Em: aheitor@uow.edu.au Tel: +61 2 4252 8232 Research Interests: Behaviour of compacted soil (small strain and large strain), stabilisation of marginal materials (including chemical for soils and mechanical for waste materials) and liquefaction analysis of partially saturated soils.

DR SHISHUN ZHANG PhD, MEng, BEng Position: Lecturer Em: shishun@uow.edu.au Tel: +61 242981427 Research Interests: FRP-strengthened concrete structures; Nonlinear finite element analysis of structures; Application of fiber-optic sensing systems in civil structures; and Seismic retrofit of RC frames.

DR PHIL FLENTJE PhD, MAppSc Position: Senior Research Fellow Em: pflentje@uow.edu.au Tel: +61 2 4221 3056 Research Interests: Geomorphology, Engineering Geology and Geotechnical Engineering. Philâ&#x20AC;&#x2122;s main work focus over the last 20 years has been engineering geology and principally Landslide Risk Management and all that entails in many areas throughout Australia. Practical and applied field work takes up a significant component of Philâ&#x20AC;&#x2122;s time. Research website: http://eis.uow.edu.au/cme/landslide-research/index.html

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Position: Research Fellow Em: qingshen@uow.edu.au Tel: +61 2 4221 4588 Research Interests: Currently working on the ARC Linkage-Projects “Cyclic behavior of unstable soils stabilized by Lignosulfonate with special reference to rapid transport infrastructure”. He has published more than 10 technical papers, including peer-reviewed journal and international conference papers. His research interests mainly include earthquake geotechnical engineering and related problems, rock dynamics, soil improvement techniques, constitutive modelling for geomaterials.

DR SANJAY SHRAWAN NIMBALKAR PhD (IIT Bombay), MTech (IIT Bombay), BEng (GCoE Pune) Position: Research Fellow Em: sanjayn@uow.edu.au Tel: +61 2 4221 3385 Research Interests: Geotechnical Earthquake Engineering, Dynamic Soil Structure Interaction, Role of Geosynthetics and Shock Mats in Railways, Artificial Neural Network in Civil Engineering, Centrifuge Modeling of Earth Structures, Finite Element Modeling, and Constitutive Modeling.

DR SUDIP BASACK PhD, MASCE, MIGS, C.Eng(India) Position: Associate Research Fellow Em: sudip@uow.edu.au Tel: +61 24221 4588 Research Interests: Ground Improvement, Stone Columns, Pile Foundations, Geo-hydraulic Engineering.

DR CHENG CHEN PhD, MSc, BEng Position: Associate Research Fellow Em: cchen@uow.edu.au Tel: +61 2 4221 5993 Research Interests: Numerical modelling in Geotechnical Engineering (DEM), ballast degradation, geogridballast interaction and track transition zone.

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PERSONNEL

DR QINGSHENG CHEN PhD, MSc, BEng

DR UDESHINI PATHIRAGE PhD, BSc (Hons)

PERSONNEL

Position: Associate Research Fellow Em: udeshini@uow.edu.au, pp695@uowmail.edu.au Tel: +61 24221 5993 Research Interests: Modelling of clogging in a permeable reactive barrier in an acid sulfate soil terrain. The Role of vegetation and associated root suction and reinforcement on the stabilisation of transport corridors and sloping ground.

DR MEHMET EREN UZ PhD, MEng (Res), BEng (Civil) Position: Associate Research Fellow Em: meuz@uow.edu.au Tel: +61 2 4239 2124 / 2286 Research Interests: Structural Optimization, Genetic Algorithms, Applications of Artificial Intelligence in Structural Design, Development of Seismic Design of Structures, Capacity of Bolted Connections in Cold-Formed Steel Plates, Hail Damage on Coated Sheet Steel Roofing.

DR ZHONGWEI WANG PhD, BSc Position: Associate Research Fellow Em: zhongwei@uow.edu.au Tel: +61 2 4221 5313 Research Interests: Advanced computational and numerical modelling, coal mine dust monitoring, simulation and control, longwall goaf gas flow and goaf fire modelling, mine ventilation simulation.

DR RUI ZHONG PhD, BEng Position: Associate Research Fellow Em: rzhong@uow.edu.au Tel: +61 2 4221 3385 Research Interests: Large strain deformation of soft clays with and without cyclic loading, vacuum preloading to mitigate excessive displacements, and theory of coupled consolidation for the application of vertical drains.

MR NOEL NOĂ&#x2030; Industrial Chemistry Certificate Position: Research Assistant Em: nnoe@uow.edu.au Tel: +61 2 4221 3019 Research Interests: Polyester synthesis and polymer production for formulation into spray able thin skin liners.

10 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

PERSONNEL Shi-Shun Zhang

Ngoc Trung Ngo

Ana Heitor

EARLY CAREER RESEARCHERS Udeshini Pathirage

2013 – 2014 ANNUAL REPORT 11

PERSONNEL

Ana Heitor received a Licentiate degree (New University of Lisbon) in 2004, a master’s (Kyoto University) and doctoral (University of Wollongong) degrees in Geotechnical Engineering in 2009 and 2013, respectively. From 2004 to 2006 she also worked in consultancy and construction companies in Portugal. During her PhD study, undertaken under the auspices of an ARC linkage project, she was honoured in the Young Geotechnical Professional Competition (2010) and with the AGS NSW Research Student Award (2012) for her innovative research work on the investigation of cost effective and non-destructive testing methods for evaluating the compaction efficiency of reclamation fills at Penrith Lakes. Her research work is also showcased in a number of scholarly academic publications, including international journals and conference proceedings.

Ngoc Trung Ngo received a Bachelor degree in Civil Engineering at the HoChiMinh City University of Technology in Vietnam in 2001. He obtained Master and PhD degrees majoring in Geotechnical Engineering at the University of Wollongong in 2008 and 2012, respectively. From 2002 to 2007 he has also been working in construction project management companies in Vietnam. During PhD study, he investigated the performance of geogrid stabilised coal-fouled ballast using a series of experimental tests and Discrete Element Method (DEM) and received the 2012 RTSA Post Graduate Thesis Award from the Railway Technical Society of Australia. Dr. Ngoc Trung Ngo has interests in conducting experimental tests including large-scale direct shear tests, cubical triaxial tests to simulate railway ballast under monotonic and cyclic loading. He also performs mathematical and numerical analyses adopting the discrete element method (DEM) and coupling the DEM with the finite difference method (FDM) to model stone column stabilised soft soils and ballasted rail tracks. His research work has been published in highly-ranked peer review journals and conferences.

Rui Zhong received a Bachelor degree of Civil Engineering and a doctoral degree of Geotechnical Engineering from Tongji University, Shanghai in 2008 and 2013 respectively. He spent 6 month at University of California, Davis as a visiting scholar from December 2011 to June 2012. He received the award of excellent graduate of Shanghai in 2008 and 2013, and developed a number of academic publications during his PhD study. Presently he is working at University of Wollongong as an associate research fellow, supported by ARC Centre of Excellence. His current research interests include Prefabricated Vertical Drains (PVDs) combined with vacuum and surcharge loading, behaviour of soft clays under cyclic loading, and geotechnical large-strain theory.

Shi-Shun Zhang is a Lecturer in Civil Engineering in the School of Civil, Mining and Environmental Engineering of the University of Wollongong (UOW). He received his PhD degree from The Hong Kong Polytechnic University (PolyU) in May 2012 and received the “Award for Outstanding PhD Theses” from the Faculty of Construction and Environment of PolyU. Before joining UOW in August 2014, he worked as a Postdoctoral Fellow at PolyU. His research interests include FRP-strengthened concrete structures, nonlinear finite element analysis of structures, application of fiber-optic sensing systems in civil structures, and seismic retrofit of RC frames. He has a number of scholarly peer-reviewed publications in reputed international journals and has also given presentations and published papers at several international conferences. He is one of the authors of the Hong Kong design guideline “Guide for the Strengthening of Reinforced Concrete Structures using FRP Composites” and the main developer of the software package “Composite Strengthening Designer” for the design of FRP-strengthened concrete structures (to be issued). He was/is the secretary-general for the 8th/9th National Conference on FRP in Construction in China and serves as a reviewer for several reputed international journals. As a key member, he coordinated several research or consultancy projects related to the FRP strengthening or fiber-optic monitoring of civil structures in Hong Kong. In addition, he participated in and assisted the Principal Investigator coordinate a 973 research sub-project funded by the National Basic Research Program of China (973 Program), which is one of the most prestigious schemes funded by the Central Government of China. As the Principal Investigator, he also secured a research grant from the National Natural Science Foundation of China.

Udeshini Pathirage graduated from the University of Moratuwa, Sri Lanka with First Class Honours in the field of Earth Resources Engineering in 2009. She received the prestigious Endeavour Award to pursue her PhD in Geotechnical Engineering at the University of Wollongong. She has delivered a number of scholarly articles in peer reviewed journals and in conference proceedings by the time she finished her doctoral degree in 2014. Currently she is researching on two topics; 1) Modelling of clogging in a permeable reactive barrier (PRB) in acid sulfate soils and 2) The role of root suction and reinforcement for strengthening transport corridors.

12 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

The School of Civil, Mining and Environmental (CME) has 10 professional staff responsible for research and laboratory activities including undergraduate teaching. Part of their role is to develop tests which include design, fabrication and construction. The operation of the test equipment often involves setting up sensors and recording the data for research activities and student projects. Alan Grant - CME Laboratory Manager Senior Technical Officer Specialisation – managing CME data acquisition including soils, structural, mining, environmental and operating specialised test equipment Cameron Nielson - Senior Technical Officer Specialisation – data acquisition including construction, design, mining, structural, environmental, fluids, and operating specialised test equipment. Duncan Best - Senior Technical Officer Specialisation – data acquisition related to civil and mining and the management and operation of the test rig at the National Rail Centre which will open in 2015. Richard Berndt - Senior Technical Officer Specialisation – soil experimentation in soft soils and hard rock for CME, data acquisition and operating specialised test equipment. Ling (Linda) Tie - Senior Technical Officer Specialisation – responsible for the management of environmental laboratories.

Fernando Escribano - Technical Officer Specialisation – design, construction and fabrication in civil engineering and operating structural test equipment. Frank Crabtree - Technical Officer Specialisation – design, construction, machining and fabrication and operation of test equipment for environmental engineering. Ritchie McLean – - Technical Officer Specialisation – design, construction, machining, fabrication and operation of test equipment for civil and mining. Richard Gasser - Technical Officer Specialisation – design, construction, machining and fabrication of test equipment for civil, mining and environmental engineering. Colin Devenish - Technical Officer Specialisation – design, construction, machining and fabrication of test equipment for mining and polymer research activities

2013 – 2014 ANNUAL REPORT 13

PERSONNEL

Professional Staff Profiles

PERSONNEL 14 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

DENNIS PERE ALAZIGHA Doctor of Philosophy An investigation on the stabilisation mechanism of lignosulfonate and its effect on swell potential of soil Supervisors: Vinod Jayan Sylaja, Buddhima Indraratna

AYOOB IBRAHIM Doctor of Philosophy (Integrated) Behaviour of Reinforced Concrete Members Supervisors: Muhammad Hadi, Neaz Sheik

JAHANZAIB ISRAR Doctor of Philosophy

MATTHEW APOLO Master of Engineering

Internal instability of granular filters under cyclic loading

DSS for Remediation of Ageing Roads in Local Government

QASIM KHAN Doctor of Philosophy

Supervisors: Lip Teh

PANKAJ BARAL Doctor of Philosophy Anisotropic viscoplastic behaviour for soft soil consolidation subjected to vacuum preloading with special reference to consolidation Supervisors: Cholachat Rujikiatkamjorn , Buddhima Indraratna

PATRICK BOOTH Doctor of Philosophy An Adaptive Model for Triple Bottom Line Optimisation of the Gas Management Life Cycle in Underground Coal Mines Supervisors: Jan Nemcik, Naj Aziz

KIRTI CHOUDHARY Doctor of Philosophy Time-Dependent Response of Soft Subgrade of Unreinforced and Reinforced Railway Tracks with Dynamic Parameters Supervisors: Cholachat Rujikiatkamjorn, Buddhima Indraratna

HUNG DUONG Doctor of Philosophy (Integrated) Drinking Water Production from Saline Solution by Membrane Distillation Using Solar Thermal Supervisors: Long Nghiem, Paul Cooper

MATTHEW GOLDSTON Master of Philosophy Reinforced Concrete beams with FRP bars under impact loading Supervisors: Alex Remennikov, Neaz Sheikh

LIBIN GONG Doctor of Philosophy

Supervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

Effect of internal FRP reinforcement and eccentric loads on ultimate conditions of FRP tube confined concrete columns Supervisors: Muhammad Hadi, Neaz Sheikh

JIANLI LIU Doctor of Philosophy Coastal Reservoir in Murray-Darling River and Its Useful Experience for Yangtze River Supervisors: Shuqing Yang, Muttucumaru Sivakumar

WENHAI LUO Doctor of Philosophy Removal of trace organic contaminants by a novel osmotic membrane bioreactor Supervisors: Long Nghiem, Will Price

MARIA MASHIRI Doctor of Philosophy Monotonic and Cyclic Behaviour of Sand-Tyre Chip (STCh) Mixtures Supervisors: Neaz Sheikh, Vinod Jayan Sylaja

SINNIAH NAVARATNARAJAH Doctor of Philosophy Use of Energy Absorbing Shock Mats for Mitigating Ballast Degradation Supervisors: Buddhima Indraratna, Sanjay Nimbalkar

LUONG NGUYEN Doctor of Philosophy Development of a membrane bioreactors (MBR) using wholecell fungi and their enzymes for the removal of trace organic contaminants Supervisors: Faisal Hai, Will Price

CNS Testing of Infilled Rock Joints Supervisors: Buddhima Indraratna

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PERSONNEL

Research Students

PERSONNEL

SASHA NIKOLIC Doctor of Philosophy

SEYED TASALLOTI Doctor of Philosophy

Understanding and Improving the Engineering Laboratory Experience

Behaviour of Blended Waste Materials for Land Reclamation for Port Extension

Supervisors: Timothy McCarthy,Tom Goldfinch

Supervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

YUJIE QI Doctor of Philosophy

KRISHANTHAN THEVAKUMAR Doctor of Philosophy

Cyclic Loading Behaviour of Compacted Granular Fills

Behaviour of Prefabricated ventral drains under cyclic loads

Supervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

QIUQIU QIAO Doctor of Philosophy

GAETANO VENTICINQUE Doctor of Philosophy

Experimental and Numerical Analysis of a Polymer Liner for use in Underground Mines

Advanced Numerical Modeling of Fracture Propagation in Rock

Supervisors: Jan Nemcik, Ian Porter

MEHDI ROBATI Doctor of Philosophy Optimal Sustainable Structural Design of Multi-Story buildings Supervisors: Timothy McCarthy

ZHENJUN SHAN Doctor of Philosophy Geotechnical Assessment of Thin Spray-on Liners (TSL) for Coal Mine Roof Support Supervisors: IanPorter, Jan Nemcik

YORK STANHAM Doctor of Philosophy Experimental and Analytical Study of Floating Wave Energy Devices Supervisors: Timothy McCarthy, Brad Stappenbelt

QIDENG SUN Doctor of Philosophy Elasto-plastic strain based approach for analysing rail track behaviour Supervisors: Buddhima Indraratna, Song-Ping Zhu

YIFEI SUN Doctor of Philosophy Optimization of Ballast Gradations for High Speed Tracks using Fuzzy Sets Supervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

PEI TAI Doctor of Philosophy Stone Columns under Cyclic loads Supervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

Supervisors: Jan Nemcik, Naj Aziz

GAOFENG WANG Doctor of Philosophy (Integrated) Development of UTBM for Gas Drainage Supervisors: Ting Ren, Chris Cook

SHUFAN YANG Doctor of Philosophy Wastewater sludge treatment by anaerobic digestion with recuperative thickening Supervisors: Long Nghiem, Will Price

JIM YOUSSEF Doctor of Philosophy Behaviour of Reinforced Concrete Members Supervisors: Muhammad Hadi

JIANSONG YUAN Doctor of Philosophy The Bonding Properties between FRP Bars and Concrete Supervisors: Muhammad Hadi

ASHLEY ZARACOSTAS Doctor of Philosophy Resource Recovery from Wastewater Supervisors: Long Nghiem, Will Price

WEIGUO ZENG Doctor of Philosophy (Integrated) Simulation and Analysis of Surface Mine Truck/Shovel System Supervisors: Ernest Baafi

YING ZHANG Doctor of Philosophy Solar Electrocoagulation and solar-thermal Vacuum membrane distillation water treatment system Supervisors: Muttucumaru Sivakumar, Shuqing Yang

16 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

MOHAMMAD ALI TASALLOTI Ali Tasalloti is currently a PhD student at the Centre for Geomechanics and Railway Engineering, School of Civil Mining and Environmental Engineering. Before joining UOW, Ali completed a Bachelor of Civil Engineering and a Master of Geotechnical Engineering at Amirkabir University of Technology (Tehran Polytechnic), Iran. He is the recipient of an Australian Postgraduate Industry Award. Ali’s research topic is focused on the behaviour of blended waste materials for land reclamation for port extension, under the supervision of Professor Buddhima Indraratna, Associate Professor Cholachat Rujikiatkamjorn and Dr. Ana Heitor. This research is an ARC linkage project for the Port Kembla Outer Harbour land reclamation. The application of his PhD work will be recycling and reusing of Coal Wash and Steel Furnace Slag blends as structural fill material for land reclamation. Ali has published several journal and conference papers and was recently awarded First Prize in the 2014 Young Professionals Geotechnical Competition hosted by the Australian Geomechanics Society and Institution of Engineers Australia.

MOHAMMAD RAMEZANIANPOUR Mohammad Ramezanianpour was born in Tehran, IRAN in 1983. Mohammad is a PhD candidate in Environmental Engineering, at the School of Civil, Mining and Environmental Engineering. He majored in water and wastewater treatment. Mohammad graduated with a Bachelor’s degree in Civil Engineering and subsequently obtained his Master’s degree in Environmental Engineering. He has successfully completed his research project (PhD thesis) devoted to treat brackish and grey water by means of a sustainable water treatment system using solar power under the supervision of Associate Professor Muttucumaru Sivakumar. A number of academic refereed publications have been produced based on PhD thesis which demonstrates the quality of this project.

THONG MINH PHAM Thong Minh Pham completed his Bachelor (Hons) of Civil Engineering at Ho Chi Minh City University of Technology in 2009. He is a recipient of the joint scholarship program between the Viet Nam Government and the University of Wollongong. Thongs started his PhD studies in July 2011 and will complete his PhD degree in December 2014. Thong’s research topic relates to the Confinement Mechanism of FRP-Confined Concrete Columns. During his PhD candidature, he was able to publish sixteen scientific papers in reputable journals and international conferences in the field of Civil Engineering. Based on his achievements, he was awarded the Peter Schmidt Memorial Scholarship for the best postgraduate student in Civil Engineering at the University of Wollongong in 2013. He has just received special commendation for his PhD thesis from all external thesis examiners.

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PERSONNEL

Research Student Profiles

PERSONNEL

TEACHING & LEARNING

18 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

THE 8TH INTER-UNIVERSITY INVITATIONAL CIVIL ENGINEERING COMPETITION The 8th Inter-University Invitational Civil Engineering Competition (8th IUICEC), was hosted by the Department of Civil Engineering at Monash University from 6th to 10th July 2014. The aim of the competition was to design an aesthetically pleasing and innovative bridge capable of withstanding each of the applied loads whilst not over designing. Twenty teams from 15 countries were invited to take part in the competition. Each team consisted of three students and one academic, including at least one female. The teams were given 23 hours in total over two days to construct their bridge from scratch at the competition. In early 2014, two groups of top Civil Engineering students were established to begin preparations for the competition. It was decided that these teams would compete against each other and the winning team would travel to Melbourne for the 8th IUICEC. The groups were supervised by two academics Prof Tim McCarthy and A/Prof Alex Remennikov. Team UOW was first to complete building the bridge on the day of the competition which demonstrated excellent resistance to a range of load conditions that included moving vehicle load, impact load and hydraulic load on the bridge piers.

by the US Department of Energy (DoE), who in 2013 collaborated with China’s National Energy Authority to run the first Solar Decathlon in China in 2013. University teams from around the world compete to get into the competition and the successful finalists are set the challenge to design, build and operate a fully solar powered house. The interesting edge to this challenge is that the students must transport their house to the competition site and fully assemble it and fit it out within just 12 days. In 2011, Team UOW was established by a core group of engineering students which included students from the School of Civil, Mining and Environment Engineering and two academics Professors Paul Cooper and Tim McCarthy. UOW became the first Australian university to make it to the final, gaining places in both the US 2013 competition and newly established Solar Decathlon China 2013 competition. Drawn by the exotic challenge of shipping a house to China and demonstrating the team’s ingenuity in the most populous country in the world, the students set about their task. Team UOW began work on the house design, a sustainable retrofit of a 1960’s Aussie fibro house. Their aim was to demonstrate that even the most humble abode could be upgraded to the highest energy efficiency standards. The university students teamed up with their counterparts in the TAFE Illawarra to create a truly student led design and construction team. The house, named the “Illawarra Flame”, took shape on the page and CAD workstation during 2012 and construction began in January 2013. In twelve weeks the house had been completed in the construction shed at TAFE. Four days later it had been completely disassembled and shipped across town for a practice re-build. The re-build was completed in seven days amidst with worst autumn storms in years. This gave the team confidence for China where they were to be allowed two weeks for construction. Finishing touches were made and the house was once again disassembled and packed in seven shipping containers and put on the sea to Tianjin Port. After 45 days at sea and 2 weeks battling customs and local shipping agents, the convoy began its 500 km trek to Datong in Shanxi, Northern China, not far from the border with Mongolia. In mid-July 2013, the team of 50 students and teachers flew in to Datong for their 5 week stay in the Energy Olympic Village.

SOLAR DECATHLON

The other teams came from all over the world: Australia, Belgium, China, Iran, Israel, Malaysia, Singapore, Sweden, UK and USA. Twenty teams representing 33 universities began the two week build. Team UOW were the first to complete construction and commissioning, well in advance of the deadline. The construction was followed by two weeks of intensive competition, monitoring, presentations and exhibition to the public. Over 35,000 visitors came through the Australian house. Over 300,000 locals visited the competition site. Coming in to the last day Team UOW was narrowly behind, in third place. The final announcement of the judged competitions gave UOW three gold medals in Architecture, Engineering and Solar application and silvers in Market Appeal and Communications. Team UOW’s final score was 957.6/1000, a solar decathlon world record, beating South China into second with Sweden third.

The Solar Decathlon is the world’s largest student led competition for solar powered homes in the world. The first Solar Decathlon was held in Washington DC in 2002 and it has been held in the USA every two years since 2005. The competition is coordinated

Team UOW has received many awards following the massive project: 2013 International Green Gown Award for Student Initiatives, Lord Mayor of Wollongong’s Australia Day Award 2014, Rotary International Pride of Workmanship award and the

TEAM UOW - INTER-UNIVERSITY INVITATIONAL CIVIL ENGINEERING COMPETITION Overall, students reflected on a unique experience they received through this competition that allowed them to take charge of the design process. Students also enjoyed learning about efficient design and thinking outside the box. The subject required a hands-on approach, which included: building and testing prototypes, material testing, soil settlement testing and use of computer packages Strand7 and AutoCAD. All of these activities made the subject interesting and also contributed to a deeper understanding of the concepts and processes involved.

2013 – 2014 ANNUAL REPORT 19

TEACHING & LEARNING

Student Competitions

2014 Engineers Australia Presidents Award. Civil engineering student and Illawarra Flame construction manager, Scott Redwood was awarded the 2013 UOW Workplace Health and Safety award for coordinating 3 builds and disassembly’s with zero accidents and injuries.

TEACHING & LEARNING

SOLAR DECATHLON - ILLAWARRA FLAME HOUSE

NEW SUBJECT AND DELIVERY METHOD CIVL 458 – FUNDAMENTALS OF CONSTRUCTION MANAGEMENT The subject CIVL 458 was delivered for the first time in the spring session of 2014. The inception of this subject aims to address a gap in the UOW Civil Engineering curriculum and to equip students with the skills set that would allow them to gain the fundamental knowledge of construction management practices which will gain them an advantage in the graduate’s employment market. Given the importance of this topic in the regional context and the very practical nature of the subject, there was a strong involvement between UOW and industry representatives from a range of Construction Management backgrounds. The industry representatives not only were instrumental in the definition of the scope of subject’s content, but also participated in the delivery engaging civil engineering students through real cases studies of local constructions projects aligned with the contents covered in every week. Anecdotal feedback from students shows that the use of real case studies promotes engaging discussion activities and allows for higher order cognitive learning during lectures and tutorials. The delivery of the subject in this way seems to promote a more rewarding learning experience for the students.

CIVL 458 - STUDENTS PORTRAYED WITH THE INDUSTRY REPRESENTATIVES LEILA SADLER, GREG KLAMUS AND GARY KENNEDY.

20 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

2013 – 2014 ANNUAL REPORT 21

RESEARCH

RESEARCH CENTRES Centre for Infrastructure Protection and Mining Safety (CIP&MS) Coordinators: Associate Professor Alex Remennikov and Associate Professor Ting Ren The Centre for Infrastructure Protection and Mining Safety (CIP&MS) is an integrated interdisciplinary research centre that facilitates, coordinates and promotes innovative activities involving wide collaboration in the areas of infrastructure protection and mining safety. The CIP&MS provides a platform for researchers from Civil, Mining and Environmental disciplines of School of CME to collaborate in order to efficiently utilise the unique technical expertise and capabilities currently existing within the School thus maximise our impact to industries. All activities and researchand-development conducted by the CIP&MS will be aimed at enhancing the image and standing of UoW as a leading research institution in line with the current UoW vision “to enrich people, communities and the environment by making original and creative connections across disciplinary, social and cultural boundaries”.

Education Research. Members of EMERG have been recognised for their teaching excellence with a number of Office of Learning and Teaching (OLT) citations and research funding. In the last five years we have been lead institution in over $1.2M in nationally competitive OLT grants in addition to being collaborating investigators on four other research projects led by other institutions. There are currently 9 PhD students working on Engineering and Mathematics Education research projects.

RESEARCH PROJECTS INCLUDE: •• Inspiring Mathematics and Science in Teacher Education •• Indigenous student support through Indigenous perspectives embedded in engineering curricula •• Understanding and improving the Engineering Laboratory Experience •• The Virtual Design Workshop: An on-line adaptive resource for engineering students •• Creating And Modifying Mathematical Learning Resources And Learning Designs For Use In Developing Countries •• Improving mathematics education in the Middle East: A focus on technology, learning design and professional development. •• Non-Response in Australian Educational Surveys

RESEARCH

RESEARCH PROJECTS

•• An evidence based model for developing undergraduate engineering mechanics education

•• Development of innovative dust monitoring and control strategies for underground coal mines;

For more information: http://eis.uow.edu.au/emerg/index. html

•• Applications of Computational Fluid Dynamics modelling of mine ventilation and dust flow characteristics ; •• Gas adsorption and desorption characteristics of CO2 rich seams; •• Nitrogen injection in directional in-seam boreholes to enhance gas drainage in low permeable seams; •• Prevention and control of spontaneous combustion and inertisation of goaf heatings; •• Dust and gas management in rapid development headings; •• Application of longwall hole directional drilling in underground coal mines •• Protection and retrofitting of buildings against effects of natural and man-made hazards, •• Safety of railway infrastructure, •• High-performance computing and modelling of effects of severe loads on critical infrastructure, •• Demolitions of large structures in Civil and Mining industries. For more information: http://www.uow.edu.au/eng/research/UOW095476.html

Engineering and Mathematics Education Research Group (EMERG)

GeoQuest Environmental Engineering Research Environmental Engineering is based on several key aspects relating to society’s interaction with the Environment. This includes the development of engineering solutions to environmental problems which impact on our land, water, air quality, and provision of clean water and air for domestic, industrial, and agricultural purposes. Our research is developed on the principle of sustainability and centres on water quality and treatment as well as water resource engineering.

RESEARCH PROJECTS INCLUDE: •• Novel high retention membrane bioreactors for sustainable water reuse: Process performance and optimization. •• Assessment and optimisation of N-nitrosamine rejection by reverse osmosis for planned portable water recycling applications. •• Optimising nanofiltration and reverse osmosis filtration processes for water recycling: effects of fouling and chemical cleaning on trace contaminant removal. •• Biosolids management: odour and volume reduction.

Coordinator: Professor Tim McCarthy

•• Co-digestion of wastewater sludge and organic waste for biogas production.

OBJECTIVES:

•• A novel carbon neutral desalination process based on forward osmosis (FO) and membrane distillation (MD).

EMERG is a group that spans across the Faculty of EIS bringing together Engineering and Mathematics researchers who have also demonstrated track record in scholarly research in the growing field of Engineering and Mathematics

•• Development of a membrane based platform for energy and resource recovery from wastewater. For more information: http://smah.uow.edu.au/geoquest/index.html

22 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Centre for Geomechanics and Railway Engineering

Environnmental Geotechnics, Filtration and Drainage

Professor Buddhima Indraratna

•• Design and construction of granular filtration for embankment dams.

•• Offshore reclamation with blended waste materials

•• Remediation of acid sulphate soils to prevent corrosion of track components. •• Role of filtration in eroded soil retention. •• Stability analysis of embankment dams and internal piping and erosion assessment. Rock Engineering and Mining Geomechanics •• Geomechanics and Mine Planning •• Jointed rock engineering. •• Rock excavations including tunnelling and mining. •• Minimisation of Geo-hazards and Geo-environmental Impact •• Landslide hazards and risk management. Computational and numerical Geomechanics •• Deep foundations and pile dynamics.

OBJECTIVES:

•• Earthquake effects on foundations.

•• Establish an inter-disciplinary research team to contribute to the innovative development of sustainable surface and sub-surface infrastructure.

•• Constitutive modelling of geomaterials .

•• Undertake challenging ground structure interaction projects. •• Conduct fundamental and applied research on modern ground improvement techniques. •• Improve the quality of research and training of postgraduate students with strategic research directions, with a focus on current industry trends.

THE KEY RESEARCH AREAS OF GRE ARE: •• Soft Ground Engineering and Ground Improvement •• Stabilising soft clay embankments using prefabricated vertical drains combined with vacuum preloading. •• Chemical stabilisation of problematic soils, including erodible, dispersive, collapsible, and unstable soils. •• Use of synthetic materials to improve subsurface drainage and reduce track deflection. •• Stabilisation of soft and weak foundation soils using native vegetation that exploits root suction. Rail Track Engineering and Transport Geotechnics •• Dynamic modelling and prediction of track performance. •• Automated monitoring of track defects. •• New materials for track components for increased ballast and sub-ballast performance. •• Assessment of rail-ballast-foundation interaction. •• Behaviour of granular materials under cyclic loads including particle degradation and cyclic densification •• Effect of slope movements on rail tracks and highway cuttings. •• Railway sub-ballast filtration under cyclic conditions.

•• Numerical and computational geomechanics. •• Stability assessment of embankments and Transport systems

ARC Centre of Excellence for Geotechnical Science and Engineering The ARC Centre of Excellence (ARC COE) for Geotechnical Science and Engineering was established in 2011 through the award of an Australian Research Council grant worth over $20 million. The Centre is expected to operate over a 7 year period via cash funding approaching $20 million, and contributions from ARC, industry, University, and NSW Science Leveraging. ARC COE was formed by merging 3 of the most active and successful geotechnical research centres in Australia: the Centre for Geotechnical and Materials Modelling (Newcastle), the Centre for Geomechanics and Railway Engineering (Wollongong), and the Centre for Offshore Foundation Systems (Western Australia). The Centre focuses on large scale laboratory experiments and advanced computational methods in Geotechnical engineering, and for the first time in Australia the Centre will combine experimental and numerical researchers into a cohesive national team. Their combined strengths will generate a powerful capability for understanding and applying Geomechanics. Researchers from the University of Wollongong will lead exciting projects in the fields of energy, transport infrastructure, and ground improvement. This will lead to many new opportunities for research students at the international leading edge of Geotechnical Engineering. The Centre is developing a major outreach program to bring this exciting field to the public. For more information: http://www.uow.edu.au/eng/research/geotechnical/index. html

2013 – 2014 ANNUAL REPORT 23

RESEARCH

The Centre for Geomechanics and Railway Engineering (GRE) has been built around several inter-disciplinary research phases to undertake advanced research into the design and performance of major infrastructure such as dams and transportation systems. It is one of the three nodes of the Australian Research Council (ARC) Centre of Excellence in Geotechnical Science and Engineering. Researchers at the Centre have successfully secured many ARC (linkage and discovery) grants, in addition to funding from the Cooperative Research Centre (CRC) for Railways, and government and industry organisation. The total annual funding for the Centre now exceeds $3 million. The proven high level research from a team of focused academics, research fellows and high calibre PhD students places the GRE Research Centre on top of the region in many key R & D areas.

•• Dams and Foundation Engineering

Mining Research Centre Director: Associate Professor Ian Porter Mining Engineering at the University of Wollongong (UOW) is a major provider of research outcomes to the Australian minerals industry. Academics are actively engaged in a number of fundamental and applied research projects which are externally funded and industry sponsored in various areas of mining engineering.

OBJECTIVES: •• To be an international provider of research outcomes to the minerals industry. •• To support the mining industry with established expertise in mine safety, ground control, and mine design.

CURRENT RESEARCH PROJECTS INCLUDE: •• Mine Safety - in the areas of coal gas migration mechanisms, underground mine dust control, dust suppression technologies, coal mine outburst control and prediction. •• Mining Geotechnical Engineering and Ground Control – with a focus on strata reinforcement, rock bolting, numerical modelling, and mine subsidence prediction.

RESEARCH

•• Computer Applications and Operations Research Methodologies – an active programme of system approach to mine productivity improvements. The work currently being conducted focuses on discrete simulation modelling, computational fluid dynamics (CFD), and numerical modelling of ground movement.

24 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

2013 – 2014 ANNUAL REPORT 25

RESEARCH

SELECTED RESEARCH PROJECTS

CIVIL ENGINEERING Densification And Degradation Of Rail Ballast Under Cyclic Wheel Loading Key researchers: Buddhima Indraratna, Cholachat Rujikiatkamjorn, Cheng Chen Funding Sources: Australian Research Council (ARC)

INTRODUCTION Cyclic densification of ballast especially under high speed freight trains has significant implications on the settlement and stability of tracks. Although the quasi-static stressstrain behaviour of granular media is generally understood, the fundamental processes of cyclic densification of ballast at increased train speeds have not been studied in-depth. A comprehensive, micro-mechanics based cyclic densification model will be developed, capturing the processes of ballast densification and associated degradation under various load frequencies through extensive laboratory and numerical studies. The research outcomes will lead to improved design and accurate deformation predictions in view of stability, safety and operational efficiency.

NUMERICAL SLEEPER TEST SIMULATIONS

RESEARCH

The sleeper test simulations using the discrete element method (DEM) have investigated the micro-mechanical behaviour of ballast under cyclic loading, and the effect of loading frequency (train speed) and axle load. Figure 1 shows the PFC3D sample model, which contains a rectangular clump simulated as the sleeper and 1468 two-ball clumps as ballast particles. In order to replicate realistic traffic loading, the sample was loaded using a sinusoidal load, which was achieved by the servo-control mechanism. The loading frequency chosen are 10, 20 and 30 Hz to represent train speeds of approximately 86, 173 and 259 km/h respectively for investigating the influence of train speed. Both normal axle load (15 tonnes) and heavy axle load (30 tonnes) were tested to evaluate the effect of axle load on ballast settlement.

LARGE-SCALE CUBICAL TRIAXIAL TEST SIMULATIONS This study is motivated by the fact that the experiments alone cannot provide a more detailed study of the micro-dynamics of the lateral flow of ballast. Large-scale cubical triaxial test simulations using PFC3D have been tested to investigate the micro-dynamics of the lateral flow of ballast, and also evaluate the effect of lateral confining pressure (10-30 kPa) on vertical settlement and the lateral spread of ballast. Figure 2 shows that the lateral displacement decreases with the increasing confining pressure in the range of 10 - 30 kPa.

Figure 2: The effect of lateral confining pressure on lateral displacements

LARGE-SCALE TRIAXIAL TEST SIMULATION USING GRADED AND REAL-SHAPED 3D BREAKABLE PARTICLES Figure 3 shows the irregular shape ballast particle model using PFC3D. Although the surface of simulated particle is not as smooth as the real one, the outline and shape of simulated particle is quite similar to real particle. Large-scale triaxial test simulation using the graded and real-shaped 3D breakable particles is ongoing. The effect of confining pressure, axle load and loading frequency on the ballast degradation and particle breakage mechanism could be investigated. The simulation results will be validated with the existing experimental data.

Figure 3: Real-shaped particle model

SUMMARY Figure 1: PFC3D sample model under cyclic loading

DEM provides a powerful numerical tool for modelling the micro-mechanical behaviour of railway ballast under cyclic loading and examining the influence of the train load and the train speed.

26 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

In the coastal areas, the soft alluvial clays with low bearing capacity and high compressibility may cause instability during the construction of the infrastructures. Hence, the technique of pre-construction consolidation is always utilised to enhance the soil strength as well as reduce the post-construction settlement. Prefabricated Vertical Drain (PVD) combined with vacuum and surcharge preloading is an attractive technique to accelerate the pre-consolidation process, which helps to reduce the economical loss of the delayed project schedule. With the assistance of the vacuum, the negative pressure can accelerate the dissipation of the excess pore pressure caused by the surcharge loading effectively, thus speed up the accumulation of the soil effective stress and maintain the ground stability. Generally, there are two types of PVD systems combined with vacuum and surcharge loading, which are membrane system and membraneless system, respectively. In the membrane system, the vacuum propagate to the PVDs through a sand blanket which covers the soft soil surface, while in the membraneless system the vacuum directly goes into the PVDs through a system of horizontal pipes connected to the vacuum pump, as shown in Fig. 1. E E

Surcharge Fill Membrane Vacuum Pump Peripheral trench Impervious slurry wall

Vacuum Pump

Surcharge Fill

Sand blanket

Drain Collector

80 60 40 20 0 -20 -40 -60 -80 0

(a) from the clay surface

-0.2

21 m 17 m

-0.4 -0.6

12 m Field data Analytical results

-0.8

8 m (b)

Figure 2: Settlement history at the Tianjin Port: (1) Loading history; (2) Settlements.

I F

100

I C

Clay

Clay PVDs

PVDs

(a) (b) Figure 1: System of PVDs combined with vacuum and preloading: (1) membrane system; (2) membraneless system.

GOVERNING EQUATION

REFERENCES Geng XY, Indraratna B, and Rujikiatkamjorn C (2012). Analytical Solutions for a Single Vertical Drain with Vacuum and Time-Dependent Surcharge Preloading in Membrane and Membraneless Systems. Int. J. Geomech., ASCE; 12(1): 27-42. Indraratna B, Rujikiatkamjorn C, Balasubramaniam AS, and McIntosh G (2012). Soft ground improvement via vertical drains and vacuum assisted preloading. Geotextiles and Geomembranes; 30: 16-23.

The consolidation progress of a soil element in the undisturbed zone is governed by:

kh  1 ∂u ∂ 2 u  kv ∂ 2 u  ∂u dq  + + = −    mv gw  r ∂r ∂r 2  mv gw ∂z 2  ∂t dt 

(1)

where, kh, kv are the horizontal and vertical permeability of undisturbed soils, respectively; mv is the coefficient of volume compressibility; γw is the unit weight of water; and u and q are the excess pore pressure and the surcharge loading. For the soil element in the smear zone, Eqn. (1) applies with the replacement of kh by ks, which means the horizontal permeability of the remoulded soil. Vacuum p is applied along the PVD as the boundary condition. Considering the loss of vacuum along the PVD, it is assumed that the vacuum pressure at the top and bottom of the PVD are p and ηp respectively, where 0<η<1.

2013 – 2014 ANNUAL REPORT 27

RESEARCH

INTRODUCTION

Due to the expansion of the Tianjin Port in China, a new pier was constructed for a storage facility on the reclamation land. Below the reclaimed soil layer (about 5 m) are soft soil layers of muddy clay (about 5 m) and soft silty clay (about 6 m) underlain by a stiff silty clay layer. PVDs and vacuum pump are adopted to accelerate the consolidation process under surcharge loading. Fig. 2 shows the good agreement between the analytical results and the field data. Vacuum Surcharge pressure (kPa) preloading (kPa)

Key researchers: Buddhima Indraratna, Cholachat Rujikiatkamjorn and Rui Zhong

APPLICATION TO A CASE HISTORY

Settlement (m)

Effectiveness of Prefabricated Vertical Drains (PVD) and Vacuum Application in the Stabilization of Soft In-Situ Clays

Ballast Track Stabilisation By Shock Mats And Geogrids Key researchers: Buddhima Indraratna and Sanjay Nimbalkar Industry Partners: Australian Rail Track Corporation Ltd. (ARTC), Aurizon (previously QR National) Sydney Trains (previously RailCorp NSW) Funding Sources: CRC for Rail Innovation; ARC Centre of Excellence in Geotechnical Science and Engineering.

INTRODUCTION

Figure 1: Placement of shock mat at bridge.

Ballast plays an important role in supporting heavy traffic loads and preventing track deformation (Indraratna et al. 2011). However, the recent use of faster and heavier trains results into deterioration of track performance. Large impact loads caused by wheel-rail irregularities aggravate ballast breakage. Use of geogrids and energy absorbing shock mats can improve the performance of rail track. Through research conducted at the Centre for Geomechanics and Railway Engineering (CGRE), effects of shock mats and geogrids on ballasted track stabilisation were assessed. Key Objectives:

RESEARCH

To determine the role of energy absorbing shock mats in reducing track degradation

To evaluate a method of determining the optimum geogrid type and aperture size for a given ballast gradation

FIELD TESTS ON INSTRUMENTED TRACK AT SINGLETON A field trial is being conducted on a section of rail track in the town of Singleton (near Newcastle) to measure transient stresses and ballast deformations (Indraratna et al. 2014). Four types of geogrids were installed at the ballast-capping interface of track sections and shock mat (Fig. 1) was placed above the concrete bridge. The track performance was monitored using sophisticated instruments (pressure cells, settlement pegs, strain gauges, transient displacement monitoring frame and fiber bragg grating sensors). The vertical deformations of sections with geogrid were generally smaller than those without geogrid. Significantly reduced deformation was observed for ballast underlain by shock mats.

COMPUTATIONAL MODELLING Figure 2 shows a FEM mesh for a section of the track analysed in Singleton. The FEM predictions were compared with field measurements, and found to be in good agreement. A comprehensive software package based on MATLAB was also developed, which is expected to be commercialised in the near future, i.e. SMART (Supplementary Method of Analysis of Rail Track) has been developed at CGRE. The use of SMART is anticipated to assist industry users to adopt modern track design approaches leading to increased track capacity, reduction in maintenance costs and increased operation efficiency.

Figure 2: Finite element mesh discretisation of a section of the rail track in Singleton.

SUMMARY Results obtained from full-scale instrumented tracks provided significant knowledge to better understand track performance using geogrids and shock mats. SMART is able to assist industry in design verification and track maintenance operations. The concepts and outcomes from this project have been further incorporated in a new project now launched under CRC for Rail Manufacturing.

REFERENCES Indraratna B, Salim W, Rujikiatkamjorn C (2011). Advanced Rail Geotechnology â&#x20AC;&#x201C; Ballasted Track. CRC Press/Balkema. Indraratna B, Nimbalkar S, Neville, T (2014). Performance Assessment of Reinforced Ballasted Rail Track, Ground Improvement, 167(1), 24-34.

28 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Investigation Of Chemical Clogging In A Permeable Reactive Barrier (Prb) Installed In Acid Sulfate Soil Key researchers: Buddhima Indraratna, Udeshini Pathirage, Laura Banasiak, Long Nghiem

where, n0 is the initial porosity, Mk is the mineral molar volume, Rk is the overall reaction rate of the mineral, Nm is the number of minerals from 1 to k, K0 is the initial hydraulic conductivity, b is the aquifer thickness, S is the storage co-efficient, and Îź, C, D are integral constants (Indraratna et al., 2014).

Industry Partners: Southern Rivers Catchment Management Authority, Douglas Partners Pty Ltd., Manildra Group

RESULTS

Funding Sources: Australian Research Council (ARC)

Recycled concrete has been a promising alkaline material for remediating acidic groundwater generated at acid sulfate soil terrains. Field results were in good agreement with the model calculations (Fig. 2). The reduction in hydraulic conductivity due to secondary mineral precipitation was only 3% at the entrance zone of the PRB, after seven years of operation.

INTRODUCTION A permeable reactive barrier (PRB) was utilised to remediate the acidic water generated from acid sulfate soil (ASS) in the Shoalhaven Floodplain South of Wollongong, Australia, where acidic groundwater is a severe environmental, social and economic problem (Fig. 1). After testing more than twenty alkaline materials, recycled concrete aggregates were chosen as a capable alkalinity source, for its ability to neutralise the acidity and precipitate dissolved aluminium and iron from groundwater.

Figure 2: Field observed results and model predictions of pH, Al and Fe concentrations in the upstream and PRB (Pathirage et al., 2014) Figure 1: Pilot-scale PRB at the study site

REFERENCES

METHODOLOGY

Indraratna, B., Pathirage, P. U., Kerry Rowe, R. & Banasiak, L. J. (2014). Coupled hydro-geochemical modelling of a permeable reactive barrier for treating acidic groundwater. Comp. Geotech., Vol. 55, No. 1, pp. 429-439.

This study simulated the performance of the PRB by coupling geochemistry with geo-hydraulics. Secondary minerals precipitated during the remediation process, caused chemical clogging, which reduced the porosity and hydraulic conductivity of the reactive material. A mathematical model was developed to capture the change in head (h) with time (t) (Eqn. 1). Commercially available finite different codes, MODFLOW and RT3D were used to simulate the timedependent modelling of the PRB. An original geochemical algorithm was developed capturing all the chemical reactions and fed into RT3D.

Pathirage, P. U., Indraratna, B., Mcintosh, G. & Banasiak, L. (2014). Modeling of mineral fouling in an alkaline permeable reactive barrier in Australia. The 14th International Conference of the International Association for Computer Methods and Advances in Geomechanics, 2014 Kyoto, Japan.

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 29

RESEARCH

PRB

The Role Of Root Suction And Reinforcement For Strengthening Transport Corridors Key researcher: Buddhima Indraratna, Udeshini Pathirage, Cholachat Rujikiatkamjorn

SUMMARY ABAQUS finite element code was used to examine the matric suction distribution around a single eucalyptus tree. The proposed root water uptake model could predict the location of the maximum matric suction change (Fig. 2).

Industry Partners: GHD Geotechnics, The City of Salisbury, New South Wales Transport Funding Sources: Australian Research Council (ARC)

INTRODUCTION Existing demand for infrastructure facilities along urban areas has been led to construct buildings, main highways and railways on soft soils. To accommodate the above, geotechnical engineering is in a more challenging situation to discover more cost effective and sustainable methods for ground improvement. In that case green corridor concept or ground improvement using native vegetation can be considered as a more attractive method. Trees are capable of increasing the suction of the soil subgrade underneath the substructure via root water uptake, in combination with the tree canopy evapo-transpiration. Moreover, tree roots provide significant mechanical reinforcement through the anchoring effect plus the additional cohesive increment due to hair roots generating osmotic suction (Fig. 1).

Figure 2: Matric suction profile after 1 year (Indraratna et al., 2006) Currently, this model is being updated to capture the effect of root reinforcement and osmotic suction along with matric suction through a series of laboratory experiments (Fig. 3) and numerical modelling. Accordingly, this study provides an advanced shear strength model coupling osmotic, evapotranspiration phenomenon.

RESEARCH Figure 1: Schematic of soil-plant-atmosphere (Indraratna et al., 2006) Empirical relations have been developed to quantify the mechanical strength for a given tree species grown under known soil conditions. Nevertheless, the effect of transpiration by tree canopy and its influence on the sustained suction equilibrium generated at the root zone for stabilising soft subgrade has not been considered rationally in the design of rail corridors. To address the above, a novel and rational computational model has been developed to quantify the overall suction effect provided by the tree roots and its continual link with the rate and magnitude of canopy evapotranspiration. Root based suction of a tree improves the shear strength and accelerates the pore water pressure dissipation. In addition it may alter the potential failure conditions of the soil-root system from a saturated to an unsaturated domain.

Figure 3: Eucalyptus plants for shear box testing

REFERENCE Indraratna B, Fatahi B & Khabbaz H (2006). Numerical analysis of matric suction effects of tree roots, Geotechnical Engineering, Institute of Civil Engineers 159(2), 77-90.

30 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Cyclic Behaviour Of Unstable Soils Stabilised By Lignosulfonate With Special Reference To Rapid Transport Infrastructure Key researchers: Buddhima Indraratna, Cholachat Rujikiatkamjorn and Qingsheng Chen

Also, the resilient modulus (MR) decreased with the increasing number of cycles (N) for untreated and LS-treated soils at all levels of cyclic loading (qcyc), especially for N>1000 (Figure 2). However, compared to the untreated soil, Mr increased significantly as a result of LS treatment. For all specimens, the values of MR decreased with an increasing value of qcyc (Chen and Indraratna, 2014a).

Industry Partners: Queensland Department of Transport and Main Roads, Chemstab Consulting Pty.Ltd, Douglas Partners, Coffey Geotechnics Funding Sources: Australian Research Council (ARC)

INTRODUCTION

LABORATORY TESTS ON LS-TREATED SOIL UNDER MONOTONIC &CYCLIC LOADING A series of laboratory tests, including the unconfined compressive strength (UCS) tests, and isotropic consolidated drained (CID) and consolidated undrained (CIU) tests under monotonic & cyclic loading were conducted on untreated and treated silty sand for varying LS contents. As expected, both USC and triaxial (CID & CIU) test results indicated that the soil strength increased significantly from LS=0% to LS=2%, but hardly any favourable effects were observed when the LS content was increased beyond 2%. More importantly, the post-peak ductility of LS-treated soil remained practically unaltered as that of the untreated soil (Chen and Indraratna, 2014b; Chen et al, 2014). The results of cyclic triaxial tests indicated that the rate of increase in axial deformation of treated specimens as a function of the loading cycles was much smaller than the corresponding LS-treated specimens (Figure 1);

Figure 2: Resilient Modulus Mr Variation as a Function of Number of Cycles for Untreated and LS-treated Sandy Silt (Nmax=50,000)

CONSTITUTIVE MODELING OF LS-TREATED SOIL A simple bounding surface plasticity model was developed to capture the bonding effects induced by lignosulfonate. A new hardening rule together with a destructuration law that can describe the different failure modes of the bonding effects is proposed, adopting a non-associated flow rule that captures the stress-dilatancy relationship. The present model is capable of providing an acceptable match with the experimental data for the LS-treated soils (Chen et al, 2014).

REFERENCES Q.S.Chen, B. Indraratna (2014a). Deformation Behavior of Lignosulfonate-Treated Sandy Silt under Cyclic Loading. Journal of Geotechnical and Geoenvironmental Engineering, 10.1061/(ASCE)GT.1943-5606.0001210 , 06014015 Q.S. Chen, B. Indraratna, J. Carter, C. Rujikiatkamjorn (2014). A theoretical and experimental study on the behaviour of lignosulfonate-treated sandy silt. Computers and Geotechnics, 61:316-327 Q.S.Chen, B. Indraratna (2014b).Shear Behaviour of sandy silt treated with lignosulfonate. Canadian Geotechnical Journal (revised manuscript submitted).

Figure 1 Axial Deformation of Untreated and LS-treated Sandy Silt as a Result of Cyclic Loading (Nmax=50,000)

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 31

RESEARCH

Although many traditional soil stabilisers (e.g. lime, cement) have been widely and effectively used for ground improvement, they often adversely affect the surrounding soil and groundwater environment. Moreover, traditionally treated soils have shown excessive brittle behaviour, especially under cyclic loads, which is often undesirable for structures such as rail embankments and airport runways (Chen et al, 2014).To overcome these problems, it is necessary to use an alternative (non-traditional) soil stabiliser that can improve the strength and durability of the soil, without harming the environment. This report describes the laboratory tests & constitutive modelling for the examination of effectiveness of lignosulphonate (LS) as an environmental friendly additive to improve the soil properties, thereby improving foundation performance.

Soft Soils Stabilized By Stone Columns For Transport Infrastructure Key Researchers: Buddhima Indraratna, Cholachat Rujikiatkamjorn and Sudip Basack Industry Partners: Coffey Geotechnics and Keller Ground Engineering Funding Sources: Australian Research Council, Coffey Geotechnics and Keller Ground Engineering

INTRODUCTION Soft ground improvement by installing stone columns has numerous benefits including increased bearing capacity and accelerated consolidation. Foundations supporting transport infrastructure is in addition subjected to cyclic loading. The specific aims of this ARC-Linkage project are: Quantifying the load displacement and consolidation characteristics of stone columns, Optimising column installation and Incorporating the influence of high frequency cyclic loads.

FIELD BASED INVESTIGATION A large number of undisturbed soil samples are collected at various depths and radial distances from the stone columns installed at Ballina bypass site. Currently, laboratory tests are in progress to investigate the installation effect on the strength, stiffness and permeability of soft clay.

LABORATORY TESTS ON SINGLE COLUMN Large-scale one-dimensional undrained triaxial tests on instrumented single stone column in soft kaolin clay were conducted (Indraratna et al. 2014). The variation of stress concentration ratios (ns) with time for various particle size distributions was studied (Fig.2). The term ns was observed to be influenced by time, depth as well as PSD.

ANALYTICAL AND NUMERICAL MODELLING The load transfer and consolidation characteristics of stone columns were captured by advanced analytical and numerical modelling (Indraratna et al. 2013) based on unit cell analogy and free strain hypothesis. The vertical stress distribution w(r) in soft soil has been quantified by the following equation:

RESEARCH

Figure 2: Stress concentration ratio versus time

SUMMARY where, r = radial coordinate, rc & re = column and unit cell radii, N = re / rc. The radial consolidation was governed by the following differential equation:

where, urt = excess pore water pressure, t = time and cvr = radial consolidation coefficient. The non-linear void ratioeffective stress of clay and the influence of cyclic loading were captured using modified Cam-clay model. Comparison of the numerical results with field test data (Fig.1) indicates reasonable accuracy of the analysis.

The soil-column stress concentration ratio depends on time, depth and PSD. Clogging retards the overall consolidation process. The average ground settlement increases asymptotically with time. The degree of improvement of soil strength and stiffness is significantly affected by column geometry, ground condition and loading pattern. Better prediction is achieved by incorporating the modified Cam-clay model. Progressive pore water pressure is built up by cyclic loading which gradually stabilizes with number of cycles and depends on frequency, amplitude and initial consolidation.

REFERENCES Indraratna, B., Basack, S. and Rujikiatkamjorn, C. (2013). Numerical Solution to Stone Column Reinforced Soft Ground considering Arching, Clogging and Smear Effects. J. Geotech. Geoenv. Engrg., 139 (3), 377-394. Indraratna, B., Siahaan, F., Rujikiatkamjorn, C. and Basack, S. (2014). Vertical Stresses in Stone Column and Soft Clay during One-Dimensional Consolidation Test. Proc. Soft Soils, Indonesia.

â&#x20AC;˘â&#x20AC;˘ Figure 1: Comparison of numerical results with field data

32 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Key researchers: J S Vinod & Buddhima Indraratna Research Collaborator: Masayuki Hyodo (Yamaguchi University, Japan)

INTRODUCTION Natural gas is one of the cleanest fossil fuels. For each unit of energy produced, natural gas emits only 25 - 50 percent less carbon dioxide than either oil or coals. In the recent past, research has shown that the oceans and polar terrestrial masses around the world hold immense amounts of methane (the primary component of natural gas) concentrated in cage-like ice structures known as Methane Hydrates (MH). Methane hydrate or clathrates contains methane, the main component of natural gas. They form under high pressure and low temperature conditions. In Australia, seismic geologic analyses have identified a few locations of methane hydrate deposits (Fig.1). Understanding the potential environmental impacts of methane gas and seabed deformation due to MH dissociation through drilling operation is important considering the production. Moreover, the marine substructures are vulnerable to sea bed deformations and no attractive technology is available so far to recover methane economically and environmentally from methane hydrate. This emphasises the need to understand the pore scale interactions between methane hydrate and soil grains which has a significant effect on the shear and deformation behaviour of methane hydrate bearing sediments. Recently, preliminary laboratory experiments have been carried out on the shear behaviour of artificially produced methane hydrate sample. However, there is only limited literature available on the understanding of methane hydrate sediment behaviour from the microscale level.

APPROACH AND METHODOLOGY The main objective of this research is to understand the shear behaviour of MH bearing sand using Discrete Element Method (DEM). The shear behaviour of hydrate bearing soil is significantly influenced by the hydrate habit growth (e.g. Pore filling, load bearing & cementation). In this study the pore filling and cementation type hydrate growth habit was modelled using PFC3D for Toyuora sand. DEM simulations were carried out very similar to the laboratory experiments carried out in Yamaguchi University. It was shown that that the deviator significantly increases with increase in MH saturation (Fig.2). Moreover, the cementation type hydrate growth may exist during shear loading of Toyuora sand in laboratory condition.

Figure 2: Deviator stress with MH saturation

SUMMARY A novel DEM model was developed to capture the shear behaviour of methane hydrate sediment mixtures. It was shown that both the approaches (pore filling & cementation) have captured the stress - strain and volumetric strain behaviour similar to the laboratory experiments. It is anticipated that with these studies, it is plausible to expect an efficient environmentally friendly extraction methods for MH will be developed if long term global gas demand warrants MH recovery.

REFERENCES Vinod, J S, Hyodo, M, Indraratna, B and Kajiyama, S (2014) Shear behaviour of methane hydrate bearing sand: DEM simulations, Inter. Symp. on Geomech. from Micro to Macro, IS-Cambridge 2014, pp. 355-359.

Figure 1: Worldwide location of MH deposit (http://woodshole.er.usgs.gov/project-pages/hydrates/primer. html)

Hyodo, M., Yoneda, J., Yoshimoto, N., and Nakata, Y. (2013). Mechanical and dissociation properties of MH bearing sand in deep seabed, Soils and Foundation, 53(2),pp. 299314.

This project will provide an understanding on the physics of interaction between methane hydrate sediments mixtures and develop a new diagnostic tool for assessing the sea bed deformation during methane gas production.

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RESEARCH

Geomechanical Behaviour Of Methane Hydrate Sediment Mixtures: Dem Simulations

United Closed-Form Solutions For Passive Piles Key researchers: Wei Dong Guo

INTRODUCTION New (screw, expanded branch) piles can double vertical pile capacity, and triple the lateral capacity of conventional piles. Their use will lower global carbon emissions by 50-70% for piling. The piles should be used in all traditional area (foundations, bridges, excavation), in building ballastless track for high-speed railway, wind-turbine foundations, and offshore foundations, and in earthquake, scour and flood prone area. In particular, coastal revetment walls and buildings should be built on the piles to resist scour and lateral spreading etc (sliding soil) owing to earthquake and tsunami. A consistent and systematic approach for designing various piles can save large cost owing to complicated design methods and input parameters. Guo (2012) have developed highly compact, closed-form solutions (underpinned by 3~4 soil related parameters). The solutions well capture nonlinear response of piles under vertical, torsional or lateral loading right up to failure. They also allow input parameters (e.g. the limiting resistance per unit length pu) to be effectively and reliably deduced, which has been empirically selected for numerical approach or conventional ultimate-state solutions over half a century. Similar solutions, however, are not available to design piles in sliding soil.

200

Guo and Ghee (2006) devised a square shear apparatus with 1×1 m2 in plan and 0.8 m in height to simulate response of passive piles (see Figure 1a). Horizontal force was applied laterally (via the lateral jack) on a loading block to translate the aluminum frames of the upper portion of the shear box (thus the adjacent sand). The loading block was made to a uniform (U, Figure 1b), an inverse triangular (T) (Figure 1c) and an arc (A) shape. It generates a U, T or A profile of soil movement at the loading location, respectively, but an unknown sand movement across the shear box and around the test pile(s). Advancing the lateral T block horizontally (see Figure 1a, Guo and Qin 2010), for instance, the frames (thus the sand) was displaced vertically (to a maximum depth lm) and horizontally at an increment of 10 mm (measured on the top frame), until a total lateral (frame) movement wf (see Figure 1a) of ~150 mm (with ws= wf-40 mm) was achieved. Typical response is obtained, including (i) The profile of the net force per unit length p on the pile to a final sliding depth lm (see Figure 2b,c); (ii) The evolution of pile deflection wg at ground-line with the soil movement wf; (iii) The rotation angle, and the maximum bending moment Mm for each displacement wg (Figure 2).

Maximum bending moment Mm (Nm)

RESEARCH

EXPERIMENTAL MODEL

Figure 1: Model tests on two passive piles (a) Tests, (b) uniform movement, (c) T- movement pu based (Constant k) prediction m = 11/18 ks= 60/50 kPa

175 150 125

m = 7/13 ks = 60/40 kPa

100

/ : without/with tran ks p =12.5/10. kN/m,

75 50

Measured (T32-0) 125 lm (mm) = 250 300

25 0

200 350

Mudline deflection wg (mm)

100

Figure 2: Pile-head displacement (wg) versus maximum bending moment (Mm)

NEW MODEL AND CLOSED-FORM SOLUTIONS A 2-layer model was developed by Guo (2014), which is underpinned by five input parameters of modulus ks and its non-homogeneity factor m, limiting force per unit length pu, non-uniform soil movement factor α, and rotational restraining stiffness kθ (= kA in Figure 3c). The model pile-soil system must satisfy force, moment equilibrium and displacement compatibility, from which new closed-form solutions are deduced.

34 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

conducted centrifuge tests on models of single piles in twolayer soil profile subjected to lateral spreading (upper layer liquefied). The models were excited in flight with an input base acceleration, which provide (a cyclic and a permanent component) of excess pore pressures; the free-field soil lateral deformations (ws), bending moment (Mm) in the piles, pile-head deflection (wg), and the ultimate profiles of bending moments. The 2-layer offer satisfactory predictions of all measured response, as shown in Figure 5c for the evolution of bending moment (Mm) with lateral spreading movement (ws). Figure 3: A model for passive piles (Guo 2014) The solutions by Guo (2014) well capture nonlinear response of 9 instrumented piles subjected to lateral spreading, or sliding slope; and reveal (1) the nonlinear response was induced by a progressively increasing sliding depth lm (resembling the pile-soil relative slip depth for static soil) and mobilization of on-pile force per unit length p (= pllm/(αl), pl = pu at pile-tip ]; and (2) a dominant elastic pile-soil interaction in the sliding soil rather than elastic-plastic interaction noted for stable soil.

A Slope Stabilising Pile: Frank and Pouget (2008) reported response of an pipe pile installed in downslope of an ‘sliding’ embankment. The pile (11.0 m in length, 0.915 m in diameter, and 19 mm in wall thickness) was instrumented with strain gauges. The soil movement was monitored using inclinometers and piezometers. During the 16- years-long test, the pile was pulled back by applying force H and moment Mo four times, while the soil sliding continued. The measured response includes the time-evolution of maximum bending moment Mm1 and the shear load Tm1 at pile-head level; the profiles of force per unit length along the pile after each ‘pulling back’; And the pile-deflection profiles prior to and after each pulling-back. The 2-layer solutions offer excellent predictions of all pertinent measured data, for instance, the bending moments Mm1 and Mm2 with the soil movement ws (see Figure 4). 1600 1400

Measured Mm2@ 1200 a depth of 8~9 m

Mmi , kNm

1000

@ depth 8.3 m

600

SUMMARY

REFERENCES

400

@ depth 3.75 m Predicted using α = 0.588 ws= wg/α

200 0

Figure 5: (a) the problem, (b) 2-layer model, (c) Predicted vs. measured Mm during lateral spreading

The 2-layer model and solutions offer great convenience for real world design (incorporating nonlinear response) of any laterally loaded piles in static, sliding soil through to scour or lateral spreading. In addition, the 4 input parameters are determined by the low-cost model shear tests rather than costly shaking tables. The current practice may be unnecessarily complicated (costing). The solutions are currently extended to capture nonlinear response of piles subjected to embankment or excavation induced loading.

Measured - Mm1 @ depth 3.75 m

800

RESEARCH

APPLICATION EXAMPLES

100

200

300

Guo, W. D. (2012). Theory and practice of pile foundations. Boca Raton, London, New York, CRC press.

400

500

Soil movement ws , mm Figure 4: Predicted versus measured bending moments Mm1 and Mm2 with the soil movement ws

Guo, W. D. (2014). Elastic models for nonlinear response of rigid passive piles. International Journal for Numerical and Analytical Methods in Geomechanics: DOI: 10.1002/ nag. 2292. Guo, W. D. and Qin, H. Y. 2010. Thrust and bending moment of rigid piles subjected to moving soil. Can. Geotech. J. 47(2): 180-196.

Pile Subjected to Lateral Spreading: Abdoun et al (2003)

2013 – 2014 ANNUAL REPORT 35

Geotechnical Properties of Granular Wastes as Potential Port Reclamation Fill

friction angle (Ď&#x2020;â&#x20AC;&#x2122;peak) computed ranged from 40o to 48o which indicates that the selected blends meet common performance based criteria for typical reclamation conditions, with peak friction angles easily exceeding 30o (Davies et al., 2011).

Key researchers: Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jayan Vinod and Ana Heitor Industry Partners: Port Kembla Port Corporation (PKPC), Coffey Geotechnics, Douglas Partners, Menard Bachy, BHP Billiton-Illawarra Coal and Australian Steel Mill Services (ASMS) Funding Sources: Australian Research Council

INTRODUCTION Coal wash (CW) and steel furnace slag (SFS) are granular wastes that result from the operation of coal mining and steel making industries. In the Wollongong region alone, the production of these granular wastes can amount to few million tonnes per year. Their effective reuse and recycling as synthetic fill materials for earthwork construction, embankments and/or structural fill materials in port expansion projects is vital for the local economy and environmental sustainability. This study encompasses the evaluation of a suitable fill material to be used for the Port Kembla Outer Harbour extension in Wollongong (Australia). SFS

Figure 2: Stress-strain behaviour of the CW-SFS blends for an effective confining stress of 30kPa

BREAKAGE

RESEARCH

A method based on the variation of the particle gradation was adopted to quantify breakage (Indraratna et al., 2005). Fig. 3 shows the incidence of breakage during compaction and shearing. As expected, the breakage is more significant for the blends having higher content of CW. Based on Fig. 3, it seems that blends with CW<50% may be preferable to avoid excessive breakage during service. CW content (%)

50mm

Figure 1: Typical aspect of SFS and CW granular waste byproducts. While the use of CW and SFS is attractive from both economic and environmental perspectives, their individual adverse geotechnical properties, i.e. breakage potential for coal wash (Indraratna et al., 1994, Rujikiatkamjorn et al., 2012) and volumetric instability (swelling) for steel furnace slag (Wang, 2010) may prevent their use as individual fill materials. This study aims to evaluate whether a blend of these two granular by-products can produce a new mixture which has smaller incidence of particle breakage and swelling while meeting the typical performance criteria for structural fills in Port conditions.

STRESS-STRAIN BEHAVIOUR OF CW-SFS BLENDS The stress strain behaviour of the source materials and selected blends was evaluated through drained triaxial tests for a range of confining pressures. Fig. 2 illustrates the typical stress-strain behaviour obtained for the selected blends and the source materials. It can be observed that the percentage of CW content has a significant influence on the shear and volumetric behaviour, i.e. the larger CW content is the lower peak deviator stress and the larger volumetric contraction is observed, due to breakage of CW particles. The effective peak

Breakage index , BI (%)

100

25.00

Compaction induced breakage total breakage Shearing induced breakage

20.00 15.00 10.00 5.00 0.00 0

100

SFS content (%)

Figure 3: Breakage index for the selected blends.

SWELLING The swelling potential of the selected blends was evaluated through one-dimensional expansion tests. It can be observed 1D volumetric expansion is significant particularly for SFS with about 8% (Fig. 4). In contrast, as expected no swelling but shrinkage was observed for CW. Furthermore, the addition of CW to the selected blends seems to suppress swelling to some extent as it was noticed a significant reduction in the maximum expansion.

36 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

10 φ'=37.1o CBR=19.5% k=6.9×10-6 cm/s

3 0

Swelling

Optimisation of CW-BOS blend as structural fill material

10.0

7.5 ng elli Sw

φ'=37.3o CBR=23% k=1.5×10-5 cm/s

25 50 75 BOS slag content: % (by dry weight)

5.0

2.5

Volumetric expansion, εvol: %

εvol=(Hf-Hi)/Hf

εvol> 0 : Swelling εvol< 0 : Srinkage

0 12.5

Swelling < 3%

Range of acceptable material

Particle breakage < 10%

Swelling induced by hot water bath (70oC)

Breakage index, BI: %

1D volumetric expansion, Volumetric expansion, εvol: % evol (%)

100 12

Coal wash content: % (by dry weight) 50 25 75

100 25

CWcontent, content a (% by(%) dry weight) Coal wash

0.0 100

Srinkage 0

25 50 75 BOS slag content: % (by dry(%) weight) SFS content

100

Figure 4: Swelling behaviour of the selected blends. (modified after Chiaro et al., 2014)

Typically the performance specifications of fill materials to be used for Port conditions rely on the characterization of the material in terms of shear strength (i.e. peak friction angle) and permeability (Davies et al., 2011). However, for CW and SFS blends, additional parameters need to be considered, such as breakage potential and swelling. A new modified criterion proposed for selecting the optimal CW-SFS blend includes four levels of acceptance and it is illustrated in Fig. 5. The region defining the optimal mixing ratio of CW and SFW lies between 70%>CW>55%. It can be observed that blend ratios within this range easily comply with the acceptance criteria defined for structural fill.

SUMMARY The potential use of a new synthetic material resultant from blending two granular wastes by-products (i.e. coal wash and steel furnace slag) is evaluated. The material index properties and the he stress strain behaviour demonstrated that the different ratios of CW and SFS blends satisfy typical port condition performance criteria in terms of strength with an overall φ’peak > 40o for all the selected blends. However, the breakage analysis conducted after compaction (i.e. placement) and after shearing (i.e. in service) showed that for blends having CW>70%, the total breakage exceeded 10%. This indicates that blend ratios with CW>70% should be possibly be avoided for use as structural fill. In addition, the swelling tests demonstrated that CW content suppress long term volumetric expansion and that blend ratios having CW>55% (i.e. <3%) may be preferable. Furthermore, while the source materials are undoubtedly influenced by breakage (CW) and swelling (SFS), the selected blends behaviour in this respect is well within acceptable geotechnical requirements to be used as an acceptable structural fill for reclamation.

Figure 5: A criteria for defining the optimal CW-SFS blend (modified after Chiaro et al., 2014).

REFERENCES Chiaro, G., Indraratna, B., Tasalloti, S. M. A. and Rujikiatkamjorn, C. (2014). Optimisation of coal wash – slag blend as a structural fill. Ground Improvement Journal, ICE (ahead of print; doi:10.1680/grim.13.00050) Chiaro, G., Indraratna, B. & Tasalloti, S.M.A. (2014) Predicting the behaviour of coal wash and steel slag mixtures under triaxial conditions Canadian Geotechnical Journal (in press) Davies, P., Philip, R. E. D. and James, D. M. (2011). Geotechnical design for the Port Botany expansion project, Sydney. Proceedings of the Institution of Civil Engineers. Geotechnical engineering 164(9): 149 –167. Indraratna, B., Gasson, I. and Chowdhury, R. N. (1994). Utilization of compacted coal tailing as a strutural fill. Canadian Geotechnical Journal 31(5): 614-623. Indraratna, B., Lackenby, J. and Christie, D. (2005). Effect of confining pressure on the degradation of ballast under cyclic loading. Géotechnique 55: 325-328. Rujikiatkamjorn, C., Indraratna, B. and Chiaro, G. (2012). Compaction of coal wash to optimise its utilisation as water-front reclamation fill. Geomechanics and Geoengineering 8(1): 36-45.

2013 – 2014 ANNUAL REPORT 37

RESEARCH

APPLICATIONS IN PORT CONDITIONS

Seismic Protection Of Infrastructure Using Scrap Tyres: An Environmentally Sustainable Approach

friendly and low cost use of advanced geomaterial (TSM) for the seismic protection of low-to-medium-rise buildings.

Key researchers: Neaz Sheikh, J S Vinod & Soledad Mashiri Research Collaborator: Hing-Ho Tsang (Swinburne University of Technology)

INTRODUCTION Over the past few decades, earthquakes have caused an average of 20,000 deaths every year together with significant damage and destructions to the properties. The investigators have proposed a novel, environmentally friendly, seismic isolation method for low-to-medium-rise buildings (common in Australia) using scrap-tyre soil mixtures (TSM). Preliminary research conducted by the investigators highlights that TSM can effectively control the response of the building during moderate earthquakes. Moreover, the use of recycled materials will positively contribute to building an environmentally sustainable society. This research project proposes environmentally sustainable use of low-cost scrap tyre-soil mixture (TSM) for infrastructures (Fig.1). However, few potential problems such as ground settlement and pore water pressure build up during cyclic loading associated with the use of TSM need urgent attention before their applications in infrastructure construction, which are within the scope of this project.

Figure 2: Damping ratio with number of cycles

SUMMARY

RESEARCH

Considering the significant amount of deaths and damages caused in recent earthquake, the research will develop a low-cost, environmentally friendly seismic isolation method using scrap tyre-soil mixtures (TSM) especially suited for low-to-medium-rise buildings. The application of scrap tyre will enhance the longevity and serviceability of the infrastructure and will minimise upgrading and maintenance costs. The successful outcomes explore the use of scrap tyre as a construction material contributing to an environmentally sustainable Australia.

REFERENCES Sheikh, M. N, Mashiri, M.S., Vinod, J.S. and Tsang, H.H. (2013). Shear and compressibility behaviour of sand-tire crumb mixtures. Journal of Material in Civil Engineering, ASCE, 25(10), 1366-1374. Mashiri, M.S., Sheikh, M., Vinod, J.S. and Tsang, H.H. (2013). “Dynamic properties of sand-tyre chip mixtures”. In S. Anderson (Eds), Australian Earthquake Engineering Society Conference 2013 (pp 1-8), Tasmania, Australia, Australian Earthquake Engineering Society,

Figure 1: Scrap tyre – soil mixture

APPROACH AND METHODOLOGY The main objective of the proposed research project is to evaluate the mechanical behaviour of scrap tyre-soil mixture (TSM) during monotonic and cyclic loading. Also, practical design guidelines will be developed for the effective use of TSM in various infrastructures. Recent experimental investigations carried out at University of Wollongong (UOW) found that TSM is a ductile material and also has the ability to absorb significant amount of seismic energy (See Fig.2). Also, it has been found in preliminary numerical analyses by the investigators and research collaborators that the proposed seismic isolation method using TSM is effective in reducing the response of low-to-medium-rise buildings in both horizontal and vertical directions. It is anticipated that this research investigation will open the door for environmentally

Mashiri, M.S., Vinod, J.S., Sheikh, M.N, and Tsang H.H. (2014) “Shear Strength and Dilatancy Behaviour of Sand–Tyre Chips Mixture”, Soils & Foundations. (tentatively accepted). Tsang, H. H., Lo, S.H. Xu, X. and Sheikh, M.N. (2012) Seismic isolation for low-to-medium-rise buildings using granulated rubber–soil mixtures: numerical study. Earthquake Engineering and Structural Dynamics. 41:2009–2024

38 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Response Of Steel Columns To Close Range Blast Loads Key researchers: Alex Remennikov and Brian Uy (UNSW) Funding Sources: Centre for Infrastructure Protection and Mining Safety (CIP&MS)

using the polystyrene spacers. TNT charges were prepared by casting molten TNT into 120 mm cubic moulds. Pentolite booster, with integral detonator well, was cast into the TNT cube charges to facilitate charge detonation centrally from the top. An average actual density of TNT was 1500 kg/m3. All explosive charges were detonated using electric initiation system. Figure 2 shows the fireball caused by detonation of the cubic TNT charges in the live tests used in this project.

INTRODUCTION Response of structural systems and elements to the blast resultants generated by a distant external explosion have been investigated thoroughly and a number of publicly accessible design guidelines, manuals and monographs are available for conducting blast vulnerability assessment studies and designing protective structures (DoD 2008). However, response of structural components to contact and close-range detonations of high explosives (HE) has not been investigated to the level sufficient for developing engineeringlevel design and analysis tools and producing reliable design recommendation. Figure 2: Fireball during explosive testing

EXPERIMENTAL RESULTS Column C1 was tested by placing the cubic TNT explosive charge on the top surface of the square steel column. The column specimen C1 failed in a catastrophic failure mode by splitting in half and forming severely deformed column remains as shown in Figure 3.

EXPLOSIVE TRIALS The aim of the blast loading trials was to investigate experimentally the response and failure modes of steel square hollow and concrete-filled square hollow sections subject to contact and close-range detonations of HE charges (Remennikov and Uy 2013, 2014). Figure 1 shows the experimental setup for testing steel columns using contact and non-contact charges. All columns were 100x5 SHS Grade 350 steel tubular sections.

Figure 3: Failure mode of Column C1

Figure 1: Experimental setup for blast testing The explosive load was provided by a square charge of trinitrotoluene (TNT) placed either directly in contact with the column surface or at the appropriate standoff above the column surface. The required standoff distances were created

The effect of small air gap between the explosive charge and the concrete-filled steel section was investigated by placing the cubic TNT charge 50 mm above the top surface of the column. Figure 4 presents the localised demolition of the specimen. One can observe a noticeable difference in the failure modes of columns C1 and C2. Column C2 was breached by the blast but it did not cause a ‘peeled banana’ destruction of the column. This demonstrates a significant effect of a small air gap between the charge and the structure in reducing the intensity of loading by the detonation products for the ‘near-field’ loading regime.

2013 – 2014 ANNUAL REPORT 39

RESEARCH

The failure modes and analytical prediction of the response of the hollow and concrete-filled steel square tubular sections subjected to a highly localized blast impulse have not been studied yet, to the best of the authors’ knowledge. This research project involves explosive trials on the steel square tubular columns subjected to the near-field blast loading effects. The experimental data are then used to validate a simplified engineering-level analysis of concretefilled steel tubular members subjected to a large-magnitude concentrated blast impact caused by a close-in detonation of HE charges.

200 175

Deflection (mm)

150 125 deformation ÂťTest 152 residual mm 100 75

SDOF Specimen C5 Test residual displ. LS-DYNA Specimen C5

50 25 0

100

Time (ms)

Figure 4: Failure mode of Column C2

NUMERICAL SIMULATION

RESEARCH

The LS-DYNA finite element model of column C5 specimen with the initial velocities is shown in Figure 5. The model includes the steel square tubular section 100x5 SHS modelled using Belytschko-Tsay shell elements. The concrete infill is modelled using constant stress solid elements. The steel square tube is modelled rigidly connected to the upstanding steel channel PFC sections, which is also modelled using shell elements. From the convergence study, a mesh size of 10 mm was found to be appropriate for the steel sections and the concrete core.

Figure 6: Comparison of numerical experimental deformations for column C5

predictions

and

SUMMARY This study has shown that simplified analytical modelling of near-field blast effects combined with modelling dynamic structural response using FE non-linear analysis can form a basis for the development of an engineering-level approach for predicting response of structures to close-in detonations of HE charges. It was demonstrated that utilising the assumption of an instantaneous detonation, the specific impulse for an explosion occurring at a short distance from a rigid obstacle can be predicted and used for the determination of the initial conditions for FE-based dynamic analyses. In this case, a structural member is analysed to the effect of a concentrated blast impact impulse inflicted by the shock wave rather than carrying out a highly complicated coupled Arbitrary Lagrange Euler (ALE) blast wave â&#x20AC;&#x201C; structure interaction analysis for close-range HE detonations.

REFERENCES Department of Defence (2008). UFC 3-340-02 Structures to Resist the Effects of Accidental Explosions. Washington, D.C.

Figure 5: (a) LS-DYNA model of Column C5 with initial velocities applied; (b) Numerical prediction of blast damage to Column C5 The blast damage of column C5 as predicted by the LS-DYNA model is presented in Figure 6. The results of numerical simulations can be qualitatively compared to the damage experienced by the specimen in the explosive test. It can be noticed that numerically predicted deformation mode is very similar to the one observed in the explosive tests.

Remennikov, A and Uy, B (2013) Simplified Modelling of Hollow and Concrete-Filled Square Tubular Steel Columns for Near-Field Detonations. In: The 15th International Symposium on the Interaction of the Effects of Munitions and Structures (ISIEMS15), Potsdam, Germany, September 17-20, 2013. Remennikov, A and Uy, B (2014) Explosive testing and modelling of square tubular steel members for near-field detonations, Journal of Constructional Steel Research, 101, pp. 290-303.

40 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

New Framework For Predicting Life Of Prestressed Concrete Sleepers Key researchers: Alex Remennikov and Sakdirat Kaewunruen Industry Partners: RailCorp, ARTC, Rio Tinto

INTRODUCTION Over the past 50 years, railway prestressed concrete sleepers have been used in rail networks around the world, especially in Europe and Japan. In Australia, concrete sleepers have been designed to withstand up to 40 tonne axle loads and used for nearly 35 years. The railway sleepers are a key structural element of railway track structures. The sleepers redistribute dynamic pressures from the rail foot to the underlying ballast bed. Based on the current design approach, the design life span of the concrete sleepers is also considered to be around 50 years. Figure 1 demonstrates a typical ballasted railway track and its components.

the positive and negative, cracking and ultimate moment capacities at the sleeper centre. Resistance of the concrete sleepers to high-magnitude wheel impact loads is investigated using the drop hammer facility at UoW. The sleepers are tested for impact strengths at the rail seat for soft, moderate and hard track conditions to simulate on-track sleeper behaviours with different track moduli. Static tests are performed in order to rate the load performance of aged concrete sleepers in accordance with Australian Standards [4-5]. Figure 2 shows the setup for rail seat vertical load tests â&#x20AC;&#x201C; positive bending moment.

Figure 1: Typical components of railway track Recent investigations showed that a railway sleeper could have experienced multiple high-intensity impact loads, causing a rapid degradation of its structural integrity and durability (Kaewunruen and Remennikov 2011). In-field, experimental and numerical data recorded by UOW has revealed that the failure of a railway sleeper is more likely be due to cumulative damage rather than due to a once-off extreme event, which might occur due to the derailment. It is important to note that, for prestressed concrete sleepers, the low magnitude but high cycle impact fatigue tends to be insignificant in comparison with the high magnitude but low cycle impact fatigue (Kaewunruen and Remennikov 2011). In contrast, it was found from a critical literature review that there is no research data related to load rating or remaining life prediction of concrete sleepers. As a result, many assumptions have been made in practice that may lead to either incorrect or inefficient asset management under constantly changing operations. This practical issue has resulted in a study to investigate the existing conditions of railway concrete sleepers and to develop a standard guidance for predicting the remaining life of such components. This study presents the experimental load rating results of railway prestressed concrete sleepers after a period of service life through a variety of structural testing programs.

EXPERIMENTAL PROGRAM Concrete sleepers are initially tested for static bending strength at the rail seat to determine both the positive and negative cracking/ultimate rail seat moment capacities. Next sleepers are tested under static loading to determine

The UOW structures laboratory contains the largest drop hammer facility for structural impact testing in Australia. The facility has the ability to generate an impact load by a free-falling mass of 600 kg from the height of up to 6 metres. Monitoring equipment includes high-capacity load cells for measuring impact loads up to 2000 kN, high speed laser displacement sensors, accelerometers, strain gauges and high-speed camera. Figure 3 presents an experimental setup for impact testing of concrete sleepers at railseat position.

Figure 3: Impact testing of concrete sleepers

SIMULATION OF TRACK SUPPORT CONDITION The experimental sleeper support conditions are grouped into Soft Track (< 20 MPa), Moderate Track (20-70 MPa) and Hard Track (100-120 MPa) for experimental simulation purposes. As shown in Figure 4, the extreme cases of track moduli can be replicated by using ballast (200 mm) over a thick layer of sand-rubber mix (50% by volume of rubber crumbs) for the very soft track, and a thin ballast layer (150 mm) on a shock mat placed directly on the concrete strong floor for the very stiff track.

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Figure 2: Static testing of railway sleepers

SUMMARY This study addresses the life of railway concrete sleepers that can be significantly affected by extreme impact loads and fatigue loading cycles. Over a period of time, the concrete sleepers age and deteriorate in addition to experiencing various types of static and dynamic loading conditions, which are attributable to train operations.

Figure 4: Simulation of track support conditions

EXPERIMENTAL RESULTS The capacity of the heavy-haul, coal-line concrete sleepers is investigated for both positive and negative moments acting at the rail seat. Figure 5 shows typical load-deformation behaviour of the concrete sleepers. 600

UOW5 UOW6

Total load (kN)

500

A new evaluation procedure (Remennikov and Kaewunruen 2014) has been developed at UOW to investigate static and dynamic load rating of aged railway concrete sleepers extracted from service lines. The structural evaluation program includes quasi-static bending tests, probabilistic analysis of the wheel-rail interface forces, dynamic impact tests, and tests to establish the current level of prestress in the steel wires. The outcomes of this research program suggest that there should be a routine periodic test program to ascertain the load rating of aged clustered sleepers and their fastening systems in the heavy haul track systems to avoid large unplanned sleeper replacement costs.

REFERENCES

400

Kaewunruen, S. and Remennikov, A (2011). Experiments into impact behaviours of prestressed concrete sleepers in railway tracks, Engineering Failure Analysis, 18(8): 23052315.

300 200 100 0 0

8 12 Displacement (mm)

Figure 5: Load-deformation characteristics of tested concrete sleepers The results from static tests on concrete sleepers that include cracking moment and the ultimate moment capacities can be used for benchmarking assessments of the concrete sleepers on a future heavy-haul rail line when planning increased traffic on that line. Sleepers are also investigated for the rail seat ultimate impact resistance. The dynamic loading programme included 10 consecutive impact load applications by the anvil. The impact loads are determined from probabilistic analysis of the incremental impact loads from the Wheel Impact Load Detectors for a specific railway line. The simulated impact loads can be varied from 600 kN to 1200 kN as shown in Figure 6 to determine the ultimate impact resistance of the sleepers. 1200

1200 kN (Test 13)

Impact Velocity: 4.5 m/s (1050 mm) 4.3 m/s (950 mm) 3.8 m/s (750 mm) 2.6 m/s (350 mm)

1000

Impact load (kN)

RESEARCH

Remennikov, A and Kaewunruen, S (2014). Experimental load rating of aged railway concrete sleepers, Engineering Structures, 76, pp. 147-162.

1020 kN (Test 12) 900 kN (Test 11)

800

600 kN (Tests 1-10)

600

400

200

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

Time (sec)

Figure 6: Range of loads applied to sleepers during impact testing

42 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Static And Dynamic Performance Of Gfrp-Reinforced Concrete Structures Key researchers: Alex Remennikov, Neaz Sheikh and Matthew Goldston Funding Sources: Centre for Infrastructure Protection and Mining Safety (CIP&MS)

INTRODUCTION

EXPERIMENTAL PROGRAM Twelve RC beams were internally reinforced with GFRP bars and subjected to static (four point bending) and dynamic loading (three point bending). Beams were designed to analyse two main parameters, reinforcement ratio (0.5, 1.0 and 2.0%) and concrete strength (40 and 80 MPa). Beams were designed to be over reinforced (concrete crushing governs), under reinforced (FRP rupture governs) and balanced. All beams had identical geometrical properties, with a rectangular cross section of 150 x 100 mm and an overall length of 2400 mm. Shear reinforcement was provided at 100 mm centre to centre spacing. Load carrying capacity, deflection and crack propagation were analysed during testing. Strain gauges were attached to the GFRP tensile reinforcement and on the top concrete surface for static beams to measure elongation during testing. The main objective from dynamic loading was to verify dynamic equilibrium by observing all forces and resisted forces the six beams were subjected to – impact load, support reactions and inertia forces. Mass of drop hammer was 110 kg, with a constant height of 1200 mm used for all impact specimens. Figure 1 shows the setup for the GFRP RC beams under static and impact loading.

Figure 1: Experimental setup for testing of GFRP RC beams: (a) static testing; (b) impact testing.

EXPERIMENTAL RESULTS GFRP Bar Tensile Testing A total of 9 tensile tests were conducted, 3 of each different size reinforcement bars. This was done to obtain experimental data of the material, including the tensile strength, elastic modulus and rupture strain. Failure was sudden and unexpected, causing the fibres to rupture and separate. Figure 2 displays a tensile test specimen in the Instron apparatus. The relationship between stress and strain was linear until failure, with no signs of ductility, see Figure 3.

Figure 2: GFRP Tensile Test – failed GFRP bar

Figure 3: Stress Strain Curve of GFRP Bar

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RESEARCH

Conventional materials are traditionally used to build resilient structures from blast attacks including concrete, masonry and steel. An alternative material to replace steel is FRP (Fibre Reinforced Polymer). The composite material is an attractive substitute for steel due to its superior properties including its non-corrosive behaviour, a significant problem for steel when exposed to marine environments, increased durability, nonmagnetic behaviour and high fatigue endurance (ACI-440 2006). Its weight to strength ratio is about 1/5 to 1/4 the density of steel. FRP has a variety of applications used for strengthening including fibre sheets or plates to the outer surface of structures (external reinforcement) including beams and columns with a strong epoxy (Attari et al. 2012). Other forms of FRP include adding fibres to the concrete mix (Yang, Min et al. 2012) or using internal reinforcement bars (Toutanji and Saafi 2000). It lacks ductility and thus fails in a brittle manner, with no warning of collapse.

Beam Static Testing A typical failure load-deformation of an over reinforced GFRP is depicted in Figure 4. Due to the low elastic modulus of the material, there is a reduction in gradient once cracking initiates. At the point of failure, the specimen has reached εcu=0.003.

Figure 5: Breakdown of resisting dynamic forces for GFRPreinforced concrete beam The impact specimens displayed shear plugs at the impact zone, as displayed in Figure 6, as a result of high shear forces for dynamic loading.

Figure 6: Failure of GFRP reinforced concrete beam under impact load

RESEARCH

SUMMARY

Beam Impact Testing

Increasing the GFRP reinforcement in the bottom layer is a major factor in increasing the load carrying capacity of the deflection and helping to decrease serviceability (deflection). Higher strength concrete showed to improve load capacity and decrease deflection at reinforcement ratios of 1.0 and 2.0%. For the impact test specimens, regardless of the shear capacity, all over – reinforced specimens displayed shear cracks around the impact zone, with formation of shear plugs present.

Equation 1 displays the vertical force equilibrium of a specimen under dynamic forces as a function of time along the beam.

REFERENCES

Figure 4: Experimental results GFRP RC Beam: (a) loaddeflection relationship; (b) concrete compressive failure.

ACI-440 (2006). “Guide for the Design and Construction of Concrete Reinforced with FRP Bars (ACI 440.1 R-06).” American Concrete Institute, Detroit, Michigan: 44

Figure 5 displays the breakdown of forces experienced by the beam during the first 50 ms. As displayed, at 0.1 s, the resisted forces were controlled by the inertia forces at initial contact. At 0.12 seconds, the impact of the drop hammer was mainly resisted by the support reactions, with the inertia forces negligible or approximately zero.

Attari, N., S. Amziane, et al. (2012). Flexural strengthening of concrete beams using CFRP, GFRP and hybrid FRP sheets. Construction and Building Materials 37: 746-757. Toutanji, H. A. and M. Saafi (2000). Flexural Behavior of Concrete Beams Reinforced with Glass Fiber-Reinforced Polymer (GFRP) Bars. ACI Structural Journal 97(5): 712719. Yang, J.-M., K.-H. Min, et al. (2012). Effect of steel and synthetic fibers on flexural behavior of high-strength concrete beams reinforced with FRP bars. Composites: Part B, Engineering 43(3): 1077-1086.

44 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Hybrid FRP-Concrete-Steel Tubular Columns Key Researchers: Tao Yu and Alex Remennikov Funding Source: ARC Discovery Early Career Researcher Award and UOWâ&#x20AC;&#x2122;S Small Grants Scheme

INTRODUCTION

COLUMN FORMS Hybrid FRP-concrete-steel double-skin tubular columns (hybrid DSTCs) consists of an outer tube made of FRP and one or more inner tubes made of steel, with the space between filled with concrete (Figure 1) (Teng et al. 2007). In hybrid DSTCs, the FRP tube offers mechanical resistance primarily in the hoop direction to confine the concrete and to enhance the shear resistance of the column; the steel tube acts as the main longitudinal reinforcement and prevents the concrete from inward spalling. The inner void may be partially filled with concrete if desired. The main advantages of hybrid DSTCs include (1) excellent corrosion resistance, as the FRP tube is highly resistant to corrosion while the steel tube is protected by the FRP tube and the concrete; (2) excellent ductility and energy-absorption capacity, as the concrete is well confined by the two tubes and outward local buckling of the steel tube is constrained by the concrete; (3) a high strength/stiffness-to-weight ratio as the inner void largely eliminates the redundant concrete; (4) ease for construction, as the tubes act as a permanent form for casting concrete and the presence of the inner steel tube allows easy connection to other members (Teng et al. 2007; Yu 2007). In addition, a direct cost comparison between a hybrid DSTC and a hollow reinforced concrete (RC) column indicates that the construction costs of the two are similar, but the former possess two important advantages over the latter: excellent corrosion resistance and excellent seismic resistance (Teng et al. 2009). Hybrid DSTCs thus have great potential in both civil infrastructure and mining infrastructure (Yu and Remennikov 2013).

Figure 1: Typical sections of hybrid DSTCs FRP-confined concrete-encased steel composite columns (FCSCs) consist of an outer FRP tube, an encased steel section and concrete filled in between (Figure 2) (Karimi et al. 2011). Similar to hybrid DSTCs, the FRP tube typically is much stronger and stiffer in the hoop direction to provide confinement and shear resistance to the column than in the axial direction. The steel section acts as the main longitudinal reinforcement. FCSCs may be constructed in-situ or precast, with the FRP tube acting as the stay-in-place form. The FCSCs are also a durable and ductile structural form. It should be noted that the concept of FCSCs can also be practised for the retrofitting/strengthening of an existing steel column.

Figure 2: Typical sections of FCSCs

RESEARCH AT UOW Intensive research on the behaviour and design of hybrid DSTCs and FCSCs is ongoing at University of Wollongong (UOW), in collaboration with The Hong Kong Polytechnic University. Research on hybrid DSTCs includes (1) the static behaviour of rectangular hybrid DSTCs (Figure 1c) and the confining mechanism of concrete in such hybrid DSTCs; and (2) the dynamic behaviour of hybrid DSTCs under lateral impact loading. Research on FCSCs includes (1) compression tests on both short and slender FCSCs to understand its static behaviour; (2) development of 3-dimensional finite element models for FCSCs; (3) development of stress-strain models for the confined concrete in FCSCs; and (4) development of design methods for FCSCs.

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RESEARCH

Corrosion of steel reinforcement in concrete structures has been the main cause of the massive infrastructure deterioration problem worldwide, while safety of structures attacked by severe hazards is also of great concern. To overcome these problems, recent extensive research has explored the use of fibre-reinforced polymer (FRP) composites in new construction, where the hybrid and optimal use of FRP with other materials (e.g. concrete and steel) to create economical and corrosion-resistant structures is a very promising direction (Teng et al. 2007). Against this background, this project is concerned with two novel forms of hybrid FRP tubular columns, namely, hybrid FRPconcrete-steel double-skin tubular columns and FRP-confined concrete-encased steel composite columns. The novel column forms are durable, ductile and have great potential to resist multi-hazards (e.g. earthquakes, vehicle impacts).

AXIAL COMPRESSION TESTS

RESEARCH

Axial compression tests on rectangular hybrid DSTCs were conducted (Figure 3). The test results showed that the concrete in rectangular hybrid DSTCs is effectively confined by the tubes, leading to a very ductile response (Cavill and Yu 2014). The outward local buckling of the steel tubes were restrained by the surrounding concrete, but inward buckling was found in most tested rectangular DSTCs, indicating that the diameter-to-thickness ratio of the steel tubes is a more critical parameter in rectangular DSTCs than in circular DSTCs.

In the tests, a 592 kg mass was released from a predetermined height to directly impact the specimens at the mid-span. A dynamic load cell was mounted on the drop hammer; a high-speed camera was used to capture the deflection during the impact process. A typical impact load-time curve is shown in Figure 5. The test results showed that hybrid DSTCs possess excellent ductility, and are able to sustain very large inelastic rotation without significant reduction in the load capacity. The maximum end rotation was found to be over 10 degrees, which is significantly higher than normally expected for reinforced concrete flexural members (i.e., 4-5 degrees). Hybrid DSTCs therefore have very good potential for resisting large blast and impact loads (Yu and Remennikov 2013).

Figure 3: Rectangular hybrid DSTCs during tests

Figure 5: Typical impact load-time curve

Axial compression tests on FCSCs were also conducted at UOW. The test results showed that the buckling of the steel section in an FCSC can be effectively restrained by the surrounding concrete and the FRP tube. The behaviour of concrete in FCSCs was found to be general similar to that in concrete-filled hollow FRP tubes, but the presence of an inner steel section led to differences in the ultimate state of the FRP tubes.

LATERAL IMPACT TESTS Lateral impact tests were conducted to investigate the dynamic behaviour of circular and square hybrid DSTCs using an instrumented drop hammer facility at UOW (Figure 4).

REFERENCES Cavill G and Yu T (2014). Rectangular Hybrid FRP-ConcreteSteel Double-Skin Tubular Columns: Stub Column Tests, Proceedings, The 23rd Australasian Conference on the Mechanics of Structures and Materials, 7-9 December, Byron Bay, Australia. Karimi K, Tait MJ and El-Dakhakhni WW (2011). Test and Modelling of A Novel FRP-Encased Steel-Concrete Composite Columns, Composite Structures, 93, 1463-1473. Teng JG, Yu T, Wong YL and Dong SL (2007). Hybrid FRPConcrete-Steel Tubular Columns: Concept and Behaviour, Construction and Building Materials, 21(4), 846-854. Teng JG, Yu T and Fernando D (2009). FRP Composites in Steel Structures, Proceedings, The Third International Forum on Advances in Structural Engineering, 13-14 November, Shanghai, China, 182-208.. Yu T (2007). Behaviour of Hybrid FRP-Concrete-Steel DoubleSkin Tubular Columns, PhD Thesis, The Hong Kong Polytechnic University, Hong Kong, China. Yu T and Remennikov (2013). Novel Hybrid FRP Tubular Columns for Sustainable Mining Infrastructure: Recent research at UOWâ&#x20AC;?, Proceedings, the 6th International Symposium on Green Mining, 24-26 November, Wollongong, Australia.

Figure 4: Instrumented drop hammer facility

46 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Reinforced Concrete (Rc) Beams Strengthened With Near-Surface Mounted (Nsm) Frp Composites Key researchers: Shi-Shun Zhang and Jin-Guang Teng (Hong Kong Polyu)

beams strengthened in flexure with NSM CFRP strips have identified several debonding failure modes (Zhang 2012). Out of these debonding failure modes, end cover separation, which involves the detachment of the NSM FRP reinforcement together with the concrete cover along the level of the steel tension reinforcement (Fig. 2), has been observed most frequently in existing tests and is the main debonding failure mode of concern in the present study.

INTRODUCTION

Stirrup

Figure 2: End cover separation

BOND BEHAVIOUR OF NSM CFRP-TOCONCRETE BONDED JOINTS Meso-Scale Finite Element Modelling of Bond Behaviour A 3-D meso-scale FE model was developed using the general-purpose FE software package MSC.MARC for the bond behaviour of NSM CFRP strips in concrete (Teng et al. 2009, 2013). The predicted failure mode is shown in Fig. 3. The FE predictions were found to be in close agreement with the test results. Most importantly, local bond-slip curves were extracted from the 3D FE predictions of the axial strains in the CFRP strip.

Tension rebar

tf hf Groove

Groove filler

hg wg

Figure 1: Flexural strengthening of RC beams with NSM FRP bars The most common FRP strengthening technique involves the external bonding of FRP laminates to the tension surface of RC members. Over the last decade, the near-surface mounted (NSM) FRP strengthening technique (Fig. 1) has emerged as an effective alternative to the externally bonded (EB) FRP strengthening technique. The NSM FRP method involves cutting grooves in the concrete cover of a RC member, filling the grooves with adhesive, and embedding into each groove an FRP bar. The most important advantage of the NSM FRP method over the EB FRP method is the improved bond effectiveness between FRP and concrete, leading to a higher debonding strain of the FRP. Due to this advantage, the method of strengthening reinforced concrete (RC) structures using near-surface mounted (NSM) FRP reinforcement has attracted increasing attention in recent years. The study presented herein was focused on NSM CFRP strips, as CFRP strips have found to be particularly attractive and desirable in NSM FRP strengthening applications due to their superior proprieties. By now, existing laboratory tests on RC

Figure 3: Predicted failure mode (half-specimen model)

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According to the 2013 Report Card of the American Society of Civil Engineers (ASCE) for America’s Infrastructure (http:// www.infrastructurereportcard.org/), the United States was estimated to need US$3,600 billion over the subsequent seven years to bring its infrastructure up to a good condition. The US problem is only an illustration of the scale of the world-wide infrastructure deterioration problem. Most of the world’s civil structures have been constructed in reinforced concrete, and corrosion of steel reinforcement has been the main cause of their deterioration. To address the massive infrastructure deterioration problem, extensive research has been conducted world-wide on the use of advanced fibrereinforced polymer (FRP) composites in the strengthening/ retrofit of existing structures (particularly RC structures) for over a decade (Hollaway and Teng 2008). FRP composites are formed by embedding continuous fibres in a resin matrix. FRP composites offer attractive solutions to the strengthening of existing structures due to a number of important advantages including their excellent corrosion resistance and a high strength-to-weight ratio. As a result, the FRP technology has become an effective mainstream technology for the strengthening of engineering structures.

Bond-Slip Model for NSM CFRP Strips in Concrete By making use of the 3-D meso-scale FE model described above, a parametric study was conducted to generate numerical data for bond-slip responses. Based on the numerical results from the parametric study, the following bond-slip model, including expressions for the interfacial fracture energy (Gf) and the maximum bond shear stress (τmax), was formulated (Zhang et al. 2013a, b):

A comparison between the bond strengths predicted by the proposed model (i.e. Eqs. 4 to 7) and those predicted by the existing bond strength model for such joints with the results of 51 test specimens collected from 7 existing studies shows that the proposed model performs significantly better than the existing bond strength model.

STRENGTH MODEL FOR END COVER SEPARATION Interaction forces between FRP and concrete in RC beams strengthened with NSM FRP bars

Where τ and s are the bond shear stress and the shear slip respectively; A = 0.72g 0.138 f c0.613 and B = 0.37g 0.284 f c0.006 ; and g is the groove height-to-width ratio (hg/wg). Comparisons of the bond-slip curves for three selected cases between the FE results and the proposed model are shown in Fig. 4, showing close agreement. 14

Proposed model (h_g/w_g=2.33)

RESEARCH

L oc a l bond s tres s ( MP a)

Proposed model (h_g/w_g=5.67)

FE analysis (h_g/w_g=2.33) FE analysis (h_g/w_g=4)

FE analysis (h_g/w_g=5.67)

6 4 2 0 0

0.2

0.4

0.6 0.8 S lip (mm)

1.2

Present method (Simplified eccentricity)

50 40 30 20 10 0 0

20 30 40 50 D is tance from the N S M bar end (mm)

FE result

Present method (Actual eccentricity)

Present method (Simplified eccentricity)

6 4 2 0 -2 -4

1.4

Figure 4: Bond-slip curves for interfaces with a concrete cylinder compressive strength of 30 MPa

D is tance from the N S M bar end (mm)

(a) Tangential interaction force (b) Normal interaction force Figure 5: Comparison of interaction forces for the RC beam strengthened with an NSM strip

Bond Strength Model of NSM CRP Strips in Concrete The basic equation for the bond strength is

Pu = 2G f E f Af C failure when Lb ≥ Le

(4)

Pu = b L 2G f E f Af C failure when Lb < Le

(5)

where Gf is the interfacial fracture energy (Eq. 2); Lb is the bond length; Le is the effective bond length; Ef and Af are the elastic modulus and the cross-sectional area of the CFRP strip respectively; Cfailure is the cross-sectional contour of the failure surface which is here taken to be composed of the three side surfaces of the groove surrounding the adhesive layer; and βL is a reduction factor to account for the effect of insufficient bond lengths. Based on numerical results from a simple beam-spring numerical model, the following equations were proposed for the effective bond length Le and the reduction factor βL (Zhang et al. 2014): Le =

1.6 h

where h 2 = t maxC failure 2G f E f A f

(6)

Lb L (2.0 8 − 1.0 8 b) Le Le

(7)

bL =

A theoretical investigation into the interaction forces between FRP and concrete in RC beams strengthened with NSM FRP bars has been conducted (Zhang and Teng 2012, 2013a). By introducing and defining two interfacial stiffness parameters, an analytical solution (Eqs. 8 to 14) for the tangential and the normal interaction forces is first obtained. The accuracy of the analytical solution is verified with predictions from a 3-D linear elastic finite element model. The numerical results from both the analytical solution and the 3-D FE model confirms the existence of high interaction forces (Fig. 5) in the bar-end regions as the cause for end debonding failure which has been commonly observed in tests.

Proposed model (h_g/w_g=4)

12 FE result

N ormal interaction force (N / mm)

T a nge ntial interaction force ( N / mm)

48 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

2-D Nonlinear FE Model for End Cover Separation

(1)

(2)

(3)

(4)

(5)

Figure 9: Typical predicted failure process

Strength Model for End Cover Separation

(a) Test

(b) Prediction

Figure 7: Typical predicted crack pattern at failure In the proposed 2-D Nonlinear FE model, the bond-slip relationship between steel bars and concrete and that between FRP and concrete were accurately modelled; and the critical debonding plane along the level of the tension steel bars was given special attention. The modelling of concrete and FRP was similar to that in the meso-sclae modelling of NSM CFRP strip-to-concrete bonded joints, and the steel reinforcement was modelled as an elastic-perfectly plastic material. Most importantly, a special cohesive-element-pair (CEP) (Fig. 6) was proposed to represent the effect of radial stresses generated by the steel tension bar (Zhang and Teng 2010, 2014a). A typical failure mode predicted by this FE mode is shown in Fig. 7. Comparisons between predictions and test results suggested for the first time ever that these radial stresses play an important role in cover separation failure and need to be taken into account to achieve an accurate model.

RESEARCH

Figure 6: Cohesive-element-pair (CEP)

To predict the ultimate shear force of an FRP-strengthened RC beam at end cover separation, the failure strain in the FRP at the inside cracked section (Point A in Fig. 8) and the position of this cracked section both need to be known. The crack spacing determines both the failure strain in the FRP at the inside cracked section and the position of this cracked section (i.e. distance from the nearest support). Based on a regression analysis of results of a parametric study conducted using the proposed simplified FE model, an expression for the FRP strain (Eqs. 15 to 19) at the inside cracked section at concrete cover separation failure was established (Zhang et al. 2012). This new strength model offers much closer predictions of the available test results than the existing models.

Simplified FE Model to Predict End Cover Separation The part of the RC beam between the two cracks near the FRP bar end can be isolated to form a simple model for FE analysis to obtain the failure strain in the FRP at the inside cracked section (Point A in Fig. 8) (Zhang and Teng 2013b, 2014b). A typical failure process predicted by this simplified FE mode is shown in Fig. 9. A comparison of the failure shear forces between the predictions of the simplified FE model (a section analysis is necessary) and test results verified the performance of the proposed simplified FE model (Zhang and Teng 2013b, 2014b). Load

P1 Rigid plate

End cover separation Tension steel

Initial crack

FRP P2

P3 Point A

Figure 8: Simplified FE model

where b R reflects the effect of moment ratio between the right and the left cracked sections, b câ&#x2C6;&#x2019; s reflects the combined effect of c d (distance between the steel reinforcement and the FRP) and s c (crack spacing), b AE reflects the effect of axial rigidity of the FRP bar A f E f , and bb / D reflects the effect of the ratio between the beam clear width bcl ear and the total diameter of the steel tension bars D t .

CONCLUSIONS Experimental studies conducted on RC beams strengthened in flexure with NSM CFRP strips have identified several debonding failure modes, and the end cover separation mode has been the most often observed debonding failure mode. A brief summary of a major recent study undertaken by the authors on the bond behaviour of NSM CFRP strips in concrete and the end cover separation failure mode of RC beams strengthened in flexure with NSM CFRP strips. In this study, a 3-D meso-scale FE model was first established for simulating

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 49

the behaviour of NSM CFRP strip-to-concrete bonded joints. Using this 3-D meso-scale FE model, the bond behaviour of the NSM CFRP strip-to-concrete interface was studied in detail, leading to the establishment of a bond-slip model and then a bond strength model for NSM CFRP strips in concrete. A full 2-D FE model for FRP-strengthened RC beams and then a simplified 2-D FE model were subsequently established. These FE models incorporated the proposed bond-slip relationship for NSM CFRP strip-to-concrete interfaces and a special cohesive element pair to reflect the effect of radial stresses generated by steel tension bars. Based on the results from a parametric study using the simplified FE model, a debonding strength model for end cover separation was finally developed for RC beams strengthened with NSM CFRP strips.

REFERENCES Hollaway, L.C. and Teng, J. G., eds. (2008). Strengthening and rehabilitation of civil infrastructures using FRP composites, Woodhead, Cambridge, U.K.

bar-end cover separation failure in RC beams strengthened with near-surface mounted FRP.” Proceedings, 12th International Symposium on Structural Engineering, 17-19 November, 2012, Wuhan, China, pp. 1018-1023 Zhang, S.S., Teng, J.G. and Yu, T. (2013a). “Bond-slip model for CFRP strips near-surface mounted to concrete.” Engineering structures, 56, 945–953. Zhang, S.S., Teng, J.G. and Yu, T. (2013b) “Bond-slip model for interfaces between near-surface mounted CFRP strips and concrete.” Proceedings, 11th International Symposium on Fiber Reinforced Polymer for Reinforced Concrete Structures, 26-28 June, 2013, Guimarães, Portugal. Zhang, S.S, Teng, J.G. and Yu, T. (2014b). “Bond strength model for CFRP strips near-surface mounted to concrete.” Journal of Composites for Construction, ASCE, 18, (Paper number: A4014003)

Teng, J.G., Zhang, S.S., Dai, J.G. and Chen, J.F. (2013). “Threedimensional meso-scale finite element modeling of bonded joints between a near-surface mounted FRP strip and concrete.” Computers & Structures, 117, 105–117. Teng, J.G., Zhang, S.S., and Dai, J.G. (2009). “Finite element modelling of FRP strips near-surface mounted to concrete.” Proceedings, 9th International Symposium on Fiber-Reinforced Polymers Reinforcement for Concrete Structures, 13-15 July, 2009, Sydney, Australia (CD-ROM).

RESEARCH

Zhang, S.S. 2012. Behaviour and Modelling of RC Beams Strengthened in Flexure with Near-Surface Mounted FRP Strips. PhD thesis, The Hong Kong Polytechnic University, Hong Kong SAR. Zhang, S.S., and Teng, J.G. (2010). “Finite element prediction of plate-end cover separation in FRP-strengthened RC beams.” Proceedings, 11th International Symposium on Structural Engineering, 18-20 December, 2010, Guangzhou, China, pp. 1794-1799. Zhang, S.S., and Teng, J.G. (2012). “Analytical solution for interaction forces in RC beams strengthened with NSM rectangular bars.” Proceedings, 6th International Conference on FRP Composites in Civil Engineering, 13-15 June, 2012, Rome, Italy (CD-ROM). Zhang, S.S. and Teng, J.G. (2013a). “Interaction forces in RC beams strengthened with near-Surface mounted rectangular Bars.” Composites Part B: Engineering, 45(1), 697-709. Zhang, S.S. and Teng, J.G. (2013b). “Simplified finite element modelling of end cover separation in RC beams flexurally-strengthened with bonded FRP reinforcement.” Proceedings, 4th Asia Pacific Conference on FRP Composites in Structures (APFIS), 11-13 December, 2013, Melbourne, Australia. (CD-ROM). Zhang, S.S. and Teng, J.G. (2014a). “Finite element analysis of end cover separation in RC beams strengthened in flexure with FRP.” Engineering Structures, 75, 550-560. Zhang, S.S. and Teng, J.G. (2014b). “End cover separation in RC beams strengthened in Flexure with bonded FRP reinforcement: simplified finite element approach.” ready for submission. Zhang, S.S., Teng, J.G. and Chen, J.F. (2012). “Analytical model for

50 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Analysis Of Hail And Other Impacts On Roofing/Cladding Key Researchers: Mehmet Uz, James Maguire and Lip Teh Key Industry Partner: Bluescope Steel Funding Source: ARC Industrial Transformation Research Hubs and UOW’S Sustainable Building Research Centre

INTRODUCTION

OBJECTIVES OF RESEARCH A review of the literature indicates that there is uncertainty regarding the relationships between the material yield stress and the dent resistance, and between the sheet thickness and the dent resistance. The yield stress and the sheet thickness are central to the development of optimum roofing profiles and cladding systems. The first objective is therefore to determine the effects of material yield stress and sheet thickness on the dent resistance of a steel sheeting. This objective involves the use of finite element simulation, plate dynamics theory and laboratory tests. The effects of other variables such as roofing profile will also be determined. One important objective is to establish a theoretical framework for measuring hailstone impact, whether on the basis of kinetic energy or momentum, or some other parameters.

Figure 1: Ice Ball Launcher device developed for hailstone impact testing at SBRC

FINITE ELEMENT MODEL VALIDATION Preliminary finite element analyses of the dynamic denting process have been carried out using ABAQUS/Explicit that is validated against laboratory test results of Vreede et al. (1995) involving steel balls, as shown in Fig. 2. The finite element analysis results match the laboratory test results quite well, as demonstrated in Fig. 3.

RESEARCH

With an insurance loss of approximately $1.7 billion and total economic costs of over $2 billion, the Sydney hailstorm of 14 April 1999 was the costliest natural disaster in the Australian insurance history (Schuster et al. 2005). With regard to COLORBOND® and ZINCALUME® steel roofing, sheets thicker than 0.42 mm is believed to remain structurally sound in the event of hailstones, but indentations may occur leading to ponding and dirt accumulation which may eventually promote corrosion. At present, there is no reliable methodology for predicting the size of indentation due to hailstone impact as a function of the material yield stress, sheet thickness, membrane stiffness, roofing profile, hailstone mass and impact velocity. The existing roof profiles are not optimised for hailstone impact resistance.

Figure 2: Validation finite element model

LABORATORY TESTS The experimental facility for hailstone impact tests including the equipment for launching ice balls (see Fig. 1) is located in the High Bay Lab of Sustainable Building Research Centre (SBRC), Innovation Campus, University of Wollongong. Ice balls of various masses will be fired onto steel roofing and cladding materials at different velocities to provide experimental data of the effects of hailstone impact on steel sheets having different yield stresses and thicknesses.

Figure 3: Comparison between the test results of Vreede et al. (1995) and the present FEA results

2013 – 2014 ANNUAL REPORT 51

Two different numerical models have been developed to simulate hail impact, as illustrated in Fig. 5: a) Lagrangian; b) Arbitrary Lagrangian Eulerian (ALE) Ice ball impact experiments had been conducted by Kim et al. (2003), Rhymer (2012) and Tippmann et al. (2013). In the present work, the simulated spherical projectile consists of 8-node reduced integration hexahedral elements (C3D8R element type in ABAQUS/Explicit), shown in Fig. 4.

Figure 6: Simulation results of 50.8 mm diameter SHI at 60.6 m/s (114 J); Compared to tests DS2-195 (Experiment 1): 60.6 m/s (114 J) and DS1-49 (Experiment 2): 61.9 m/s (108 J)

Figure 4: Quarter model biased mesh of 50.8 mm diameter SHI and rigid target

RESEARCH

The simulated hail ice (SHI) projectile was modelled using a Lagrangian mesh. A quarter-model of the spherical projectile was used along with quarter-symmetry boundary conditions. The impact force histories of a 50.8 mm ice ball impacting the force measurement bar (the rigid target) at 60.8 m/s and at 61.9 m/s are shown in Fig. 6 with the corresponding still images shown in Fig. 7. For better clarity, the quarter model results are patterned cylindrically to represent the view of a complete SHI. The force-time history result of the present work is quite consistent with the laboratory test results in terms of the peak force magnitude and impulse. The experimental cracking phenomenon is matched by the finite element simulation with the failed elements propagating from the impact interface to the backside.

a) 36 μs

b) 135 μs

Figure 7: Comparison between experimental observation and FEA simulation; 50.8 mm SHI at 60.6 m/s (114 J).

REFERENCES Kim, H., Welch, D.A., and Kedward, K.T., 2003. Experimental investigation of high velocity ice impacts on woven carbon/ epoxy composite panels. Composites Part A: Applied Science and Manufacturing, 34(1), 25-41. Rhymer, J.D., 2012. Force criterion prediction of damage for carbon/epoxy composite panels impacted by high velocity ice. Ph.D. dissertation, University of California, San Diego. Schuster, S.S., Blong, R.J., Leigh, R.J., and McAneney, K.J., 2005. Characteristics of the 14 april 1999 sydney hailstorm based on ground observations, weather radar, insurance data and emergency calls. Nat. Hazards Earth Syst. Sci., 5(5), 613-620. a) b) Figure 5: Numerical approaches for the ice: a) Lagrangian b) ALE

Tippmann, J.D., Kim, H., and Rhymer, J.D., 2013. Experimentally validated strain rate dependent material model for spherical ice impact simulation. International Journal of Impact Engineering, 57(0), 43-54. Vreede, P.T., Tamis, P.J., and Roelofsen, M.E., 1995. The influence of material properties and geometry on dynamic dent resistance: Experiments and simulations. In IBEC’95 Materials and Body Testing: IBEC, 79-86.

52 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

SELECTED PUBLICATIONS

Novel Membrane Processes For Sustainable Water Resue And Seawater Desalination

Laboratory and pilot scale equipment for the project: (a) MBR; (b) Direct contact membrane distillation; (c) NF/RO cross flow filtration rig; (d) MBR-FO system; (e) Granular activated carbon adsorption columns; (f) Ozone generator; and (g) pilot scale RO plant.

Key researchers: Long D. Nghiem and Faisal I. Hai Further information: http://www.uow.edu.au/~longn; http:// www.uow.edu.au/~faisal A major challenge to mankind is to provide adequate clean fresh water for sanitation as well as industrial and agricultural production. This problem is further heightened in Australia where the climatic pattern is characterised by intense droughts and flooding rains. Despite being the driest continent on Earth, Australia has been a provider of reliable and high quality food to its neighbouring countries and has recently set a national target to become the food bowl of Asia. The key challenge to achieving this target is to ensure ample and steady supply of fresh clean water, that is independent of the hydrological cycle, for urban and agriculture consumption. This project directly contributes to the national effort of securing our fresh water supply by developing and optimising innovative membrane based processes for water reuse and seawater desalination applications. This cluster of projects is supported by The Australian Research Council, Veolia Water, Seqwater, Shoalhaven Water and GeoQuEST (UOW).

(a)

(b)

(c)

(d)

(e)

(g)

Luo, W., Hai, F. I., Price, W.E., Guo, W., Ngo, H.H., Yamamoto, K. and Nghiem, L.D. High retention membrane bioreactors: challenges and opportunities. Bioresource Technology, 167 (2014) 539-546.

Wijekoon, K.C., Hai, F. I., Kang, J., Price, W. E., Cath, T. and Nghiem, L. D. (2014) Rejection and fate of trace organic compounds (TrOCs) during membrane distillation. Journal of Membrane Science, 453 (2014) 636-642.

3. Tu K.L., Fujioka T., Khan S.J., Poussade Y., Roux A., Drewes J.E., Chivas A.R., and Nghiem L.D., Boron as a surrogate for N-nitrosodimethylamine (NDMA) rejection by reverse osmosis membranes in potable water reuse applications. Environmental Science and Technology, (Accepted 13 May 2013). 4. Xie, M., Nghiem, L.D., Price, W.E., and Elimelech, M., Comparison of the removal of hydrophobic trace organic contaminants by forward osmosis and reverse osmosis. Water Research, 2012. 46(8): p. 2683-2692. 5.

Fujioka, T., Khan, S.J., McDonald, J.A., Henderson, R.K., Poussade, Y., Drewes, J.E., and Nghiem, L.D., Effects of membrane fouling on N-nitrosamine rejection by nanofiltration and reverse osmosis membranes. Journal of Membrane Science, 2013. 427: p. 311-319.

(f)

2013 – 2014 ANNUAL REPORT 53

RESEARCH

ENVIRONMENTAL ENGINEERING

Biosolids Management And Renewable Energy Production

SELECTED PUBLICATIONS 1.

Semblante, G. U., Hai, F. I., Ngo, H. H., Guo, W., You, S. J., Price, W. E. and Nghiem, L. D. (2014) Sludge cycling between aerobic, anoxic and anaerobic regimes to reduce sludge production during wastewater treatment: performance, mechanisms, and implications. Bioresource Technology, 155 (2014) 395-409.

Nghiem, L.D., Nguyen, T.T., Manassa, P, Fitzgerald, S.K., Dawson, M., Vierboom, S., Co-digestion of sewage sludge and crude glycerol for on-demand biogas production” International Biodeterioration & Biodegradation, 95 (2014) 160-166.

Key researchers: Long D. Nghiem and Faisal I. Hai Further information: http://www.uow.edu.au/~longn; http:// www.uow.edu.au/~faisal Wastewater treatment generates a large amount of solid product or sludge. This can be treated to produce biogas (a valuable renewable fuel) and biosolids for beneficial reuse. Sydney Water, the largest water utility in Australia, produces about a fifth of the total biosolids production of Australia. The management of these biosolids is a major cost to Sydney Water. Biosolids produced from wastewater treatment plants have tremendous potential for use as fertilisers. However, current treatment processes are generating major issues with the production of malodour. This means that the treatment plant authorities have to transport these substances great distances to customers, at significant cost. If the sludge odour can be reduced or eliminated, new market options much closer to the plants could be explored. It is thus necessary to understand the factors which contribute to the excess generation of malodourous sludge. This will facilitate formulation of more effective control regimes, which will substantially alter the economics of biosolids management.

3. Nghiem, L.D., Manassa, P., Dawson, M. and Fitzgerald, S. K. Oxidation reduction potential as a parameter to regulate micro-oxygen injection into anaerobic digester for reducing hydrogen sulphide concentration in biogas. Bioresource Technology (accepted, September, 2014). 4. Phan, H.V., Hai, F.I., Kang, J., Dam, H.K., Zhang, R., Price, W.E., Broeckmann, A., Nghiem, L.D. (2014) Trace organic contaminant (TrOC) removal by an anoxicaerobic membrane bioreactor (MBR) : Biological stability and trace organic compound removal., Bioresource Technology,165 (2014) 96-104.

UOW is working with Sydney Water to improve the efficiency and effectiveness of its management of biosolids. There are three main aspects to this:

RESEARCH

•

Reducing the overall volume of sludge being produced

•

Improving the yield of biogas from the sludge

•

Minimising the production of malodours associated with biosolids.

This cluster of projects is supported by Sydney Water and GeoQuEST (UOW).

54 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Key researchers: Faisal I. Hai and Long D. Nghiem Further information: http://www.uow.edu.au/~faisal; http://www.uow.edu.au/~longn

Figure: Schematic of TrOC degradation by mediator-enhanced enzymatic catalysis on solid support Evidence shows that a range of trace organic contaminants (TrOCs) which are suspected to have adverse impacts on humans and wildlife are not completely removed from wastewater by the conventional bacterial processes. Accordingly these TrOCs have been detected in sewageimpacted surface waters all over the world, including Australia. Development of cost-effective methods for TrOC removal is crucial for the safety of the downstream production of water for human consumption. To address this, this project proposes to use fungal-derived oxidative enzymes which have been reported to be useful for the remediation of a wide range of environmental contaminants. To fully exploit the comparative advantages of fungal degradation over bacterial remediation, this project will employ immobilization of enzyme in gel or porous matrix including membranes to improve its stability against thermal and chemical denaturation, and will simultaneously add ‘mediator’ compounds to broaden the range of TrOCs that the enzyme can degrade. The degradation of TrOCs of diverse chemical structures by the proposed combination will be evaluated and the associated biodegradation pathways elucidated. Understanding of the biodegradation pathways will allow more appropriate design and thus contribute to substantial economic savings.

enzymatic hydrolysis to increase the reaction speed and the conversion rate. This cluster of projects is carried out in collaboration with Novozymes Australia, BactiGro Australia, and Metgen Finland with support from GeoQuEST (UOW).

SELECTED PUBLICATIONS 1.

Yang, S., Hai, F.I., Nghiem, L. D., Price, W., Roddick, F., Moreira, M. T. and Magram, S.F. (2013) Understanding the factors controlling the removal of trace organic contaminants by white-rot fungi and their lignin modifying enzymes: a critical review. Bioresource Technology, 141 (2013) 97-108).

Nguyen, L.N., Hai, F.I., Price, W.E., Leusch, F.D.L., Roddick, F., Ngo, H.H., Guo, W., Magram, S.F. and Nghiem, L.D. The effects of mediator and granular activated carbonn addition on degradation of trace organic contaminants by an enzymatic membrane reactor. Bioresource Technology, 167 (2014) 169-177.

3. Hai, F. I., Fattah, K. P., Saroj, D. P. and Moreira, M. T. “Membrane reactors for bioethanol production and processing” in Membrane Reactors for Energy Applications , (eds. Basile, A., Di Paola, L., Hai, F.I., Piemonte, V.), Woodhead publishing, UK, 2014 (Accepted). 4. Membrane Biological reactors, (eds. Hai, F.I., Yamamoto, K. and Lee, C.-H.), IWA publishing, UK, 2014 (ISBN 9781780400655). 5.

Nguyen, L. N., Hai, F. I., Yang, S., Kang, J., Leusch, F. D. L., Roddick, F., Price, W. E. and Nghiem, L. D. Removal of trace organic contaminants by an MBR comprising a mixed culture of bacteria and white-rot fungi. Bioresource Technology, 148 (2013) 234-241.

Another aspect of this project is enzymatic biofuel production. Dwindling supplies of fossil fuel along with detrimental release of greenhouse gases have led to the quest for renewable sources of fuel such as bioethanol from cellulosic materials (e.g., sugar cane, corn starch, wood). Conversion of biomass to bioethanol involves a set of ‘biotransformation’ and ‘recovery/concentration’ processes. With the help of membrane technology, several process steps that were conventionally separate can be integrated and the production of bioethanol simplified. Raw material usually undergoes pretreatment (hydrolysis) via an enzymatic hydrolysis to release sugars such as glucose or xylose before it is fed to fermentation for ethanol production. This study will focus on membrane use in enzymatic pretreatment of cellulose. Membranes can be used to recover glucose during the

2013 – 2014 ANNUAL REPORT 55

RESEARCH

Biocatalytic Membrane Reactors For Trace Organic Contaminant Removal And Biofuel Production

Solar Powered Water Treatment System Key researchers: Muttucumaru Sivakumar, Mohammad Ramezanianpour, Shuqing Yang and Ying Zhang Funding Sources: GeoQuest Research Centre

INTRODUCTION

RESEARCH

Sustained water scarcity conditions due to increased fresh water demand necessitates water authorities to consider various alternatives as supplementary water supplies. Water recycling in a sustainable manner is increasingly being practised around the world. Abundantly available brackish water sources with suitable treatment can be used for recycling purposes. On the other hand, grey water recycling is considered as a reliable source of supply as it is generated near the source. A typical household’s grey water contains approximately 70% of the domestic wastewater and its TDS, COD and TOC concentrations are approximately 50, 40 and 38% less than the strength of average domestic wastewater. Grey water treatment for reuse will not only decrease the rate of fresh water consumption in urban areas but also will reduce the pressure on wastewater treatment plants. These substantial improvements are obtainable by means of an appropriate treatment technology in a sustainable and efficient manner. Water is also closely interconnected with energy. Water extraction, treatment, transport and distribution all requires energy. In regard with the exigent situations predicted for water and energy in future as well as their interactions, the potential of solar powered treatment technologies are investigated as an attractive and promising solutions.

able to store data of temperature sensors, pressure probes and flow meters. Available models for prediction of the permeate flux were evaluated using observed experimental data. These data indicated that the permeate flux is highly influenced by variation of permeate side pressure followed by feed temperature and flow rate. Also, variation of these parameters was investigated in terms of energy consumption to determine an efficient combination of operating parameters. Optimum operating parameters were 7kPa pressure, 65˚C temperature and 1 L/min flow rate. On the other hand, quality of the permeate water was measured after each test to determine the amounts of turbidity, coliform count, TDS, TOC, TN, Ca, Mg, Na, Fe and Al. The water quality tests performed for four brackish water samples (groundwater, seawater, mine water and swimming pool salt water) before and after treatment showed that VMD can remove 99.9 % TDS from raw water samples along with complete rejection of coliforms. Measured parameters of the permeate water met the Australian water quality guidelines for multi-purpose re-use.

SUSTAINABILITY ASSESSMENT OF TREATMENT TECHNOLOGIES This research compared three innovative solar-based treatment systems from a selection of a broad range of technologies that have been used for brackish and grey water treatment. The treatment systems were assessed through a multi-criteria decision analysis method embedding twelve sustainability indicators under three major criteria. Pairwise comparison of indicators and selected systems revealed that the solar powered vacuum membrane distillation (SVMD) system was the most sustainable technology option for both brackish and grey water treatment based on economic, environmental and social sustainability pillars.

Figure 1: VMD experimental set up.

MODELING OF FLUX DECLINE Membrane lifetime and the performance of MD process are influenced by scaling and pore wetting. A new analytical model incorporating the scaling and/or intermediate pore blocking followed by cake formation was developed to predict descending rate of the permeate flux as:

LABORATORY EXPERIMENTS Vacuum membrane distillation (VMD) is an emerging technology for water treatment which comprises of evaporation and condensation processes that mimic the water cycle in the nature. Higher rate of flux produced by VMD distinguishes this method from other types of membrane distillation processes. A lab scale VMD treatment system was set up to demonstrate the response of the permeate flux rate to the various operating parameters as shown in Fig. 1. The permeate flux rate achieved were between 0.27 to 6.44 L/ m2.h. The maximum flux rate was obtained at 65 ˚C feedwater temperature, 6.90 L/min feed flow rate and 7 kPa absolute pressure on the permeate side. An online data acquisition system for VMD incorporating LabVIEW program is

The model simultaneously combined force balance and pore blockage theories to illustrate the open pore-area reduction on the membrane surface. This model after calibration provided excellent fits to a range of experimental flux data as shown in Fig. 2. Sensitivity analysis of the model was carried out for variation of flow rate, viscosity, particle size, crystal shapes and concentration of feed solution. The model is highly influenced by TDS and TSS concentration, particle diameter and feed water flow rate. The model has been verified for the application of VMD for brackish water samples.

56 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Figure 2: Permeate flux experimental data (■) and the proposed model flux (─) at T=55 °C and P=10 kPa using NaCl solution with concentration 50 g/L.

WETTING OBSERVATION AND TESTING

FIELD TESTS ON INSTRUMENTED TRAILER AND SIMULATION STUDY Solar energy was embedded into the VMD process. An innovative Solar Vacuum Membrane Distillation (SVMD) unit was designed, assembled and tested as shown in Fig 3. A simulation study of heat and mass transfer of a membranebased distillation process was developed using assigned equations for the components. The performance of the system was continuously monitored over a two month day time period under natural and dynamic local weather conditions. The simulated model was validated against experimental data and it was shown that the model is highly sensitive to solar irradiance since the operating pressure and flow rate were kept constant. The model predicted well the experimental observations of treated permeate flux when fresh water was used as a feed. Sensitivity of the simulated permeate flux was investigated for variation of pressure, temperature, flow rate values and membrane characteristics.

Figure 3: Solar powered vacuum membrane distillation system.

HIGH QUALITY WATER EXTRACTION FROM GREY WATER BY MEANS OF SECVMD To overcome the problem of pore wetting for grey water treatment by SVMD, electro-coagulation (EC) was incorporated as a pre-treatment unit. EC is an effective technology for LAS removal. The COD and TOC concentration was reduced by 85.8 and 71.0 %, respectively by the EC process. A range of current density and circulation rate of EC unit was performed, and the permeate water quality was monitored. The two factors: water quality and energy consumption determined the optimised value for current density and circulation rate. The EC unit was combined with SVMD system (called the SECVMD), so that a successful field test under real condition was carried out.

SUMMARY Innovative aspect of this research work takes into account the three pillars of sustainability assessment using a multicriteria decision analysis method for brackish and grey water treatment. The solar powered electro coagulation and vacuum membrane distillation (SECVMD) is the world’s first solar powered vacuum membrane distillation unit that has the ability to treat grey water at source. SECVMD can potentially save up to 70 % of water in a typical household if all grey water generated is treated. A new analytical model development along with simulation study has been performed for such an innovative treatment system. Both theoretical and experimental studies will help engineers to better design a high quality water production system in future. More research needs to be undertaken at a pilot scale to proof the viability of this system for a real world application.

2013 – 2014 ANNUAL REPORT 57

RESEARCH

The VMD process is rarely used for wastewater treatment due to penetration of feed through the membrane as a result of active surfactants present in detergents and this can be measured as linear alkylbenzene sulfonate (LAS). The presence of LAS will reduce the contact angle between the solutions and the membrane surface. The contact angle tests performed for natural and synthetic grey water samples illustrated that direct treatment of these water sources are impossible using polypropylene (PP) and polyvinylidene difluoride (PVDF) membrane types for VMD process due to pore wetting. An empirical model was proposed to correlate contact angle and LAS concentration. Experimental works were carried out for three hydrophobic membranes. The highest values for contact angle were achieved by polytetrafluoroethylene (PTFE) followed by polyvinylidene difluoride (PVDF) and polypropylene (PP) membrane types. The observation also showed that the contact angle decreases in the presence of surfactants and has to be maintained above 90º for a membrane used in VMD process.

MINING ENGINEERING A new dust monitoring methodology for Australian longwall mines Key researchers: Ting Ren and Brian Plush Industry Partners: BHP Illawarra Coal, Peabody Energy and Glencore Coal Funding Sources: Australian Coal Association Research Program

INTRODUCTION Fugitive dust on longwalls has always been an issue of concern for production, safety and the health of workers in the underground coal mining industry both in Australia and globally. Longwall personnel can be exposed to harmful respirable and inhalable dust from multiple dust generation sources including, but not limited to: intake entry, belt entry, stageloader/crusher, shearer, and shield advance, as shown in Figure 1. With the increase in production created from the advancement in longwall equipment, dust loads have also increased and this has resulted in an increase in exposure levels to personnel.

PROJECT OBJECTIVES This project aims to develop a new dust monitoring methodology to quantify and document both respirable and inhalable dust magnitudes generated from different sources, using gravimetric sampling as per statutory requirements in conjunction with real-time dust monitors, and to identify and determine the combination of best control practices for dust mitigation on longwalls. This project aims to address some of the immediate industry concerns in dust monitoring and controls, specifically: • Provide a critical review of the current inhalable & respirable dust sampling methodologies used in NSW and other states in Australia as well as internationally to identify their merits and limitations against codes, guidelines and standards; • Develop a new sampling methodology applicable to underground longwall coal mining tasks to more accurately measure and quantify dust loads at identified sources of dust generation utilising gravimetric sampling and real time monitors; • Conduct field trials and demonstrations of the reliability and robustness of the new methodology by carrying out dust monitoring at selected coal mines in NSW to investigate and determine its validity against codes, guidelines and standards;

RESEARCH

• Evaluate current dust controls and their effectiveness at each of the above sources of dust generation, and analyse the most effective control process in place for each dust source at other longwall mines in Australia and globally; and • Establish a database of best practices for implementation on Australia longwalls to minimise dust exposure levels.

DUST MONITORING METHODOLOGY

Figure 1: Longwall dust generation sources The industry has been using statutory dust measurements in underground coal mines conducted by both SIMTARS and Coal Services according to AS 2985 for respirable size dust particles, and AS 3640 for inhalable size dust particles. The majority of dust sampling to date has been done with cyclone separation and collection of the sized particles for weighing, generally over the period of a full shift. Although this method provides an accurate measurement for the total dust exposure for the period sampled, it does not always accurately reflect the source, quantity and timing of respirable dust entering the longwall from different sources, hence presents difficulties in determining the relative effectiveness of the different control technologies in use. Tests based on this methodology also have a number of limitations including limited information from the results and the large number of invalid samples due to over-exposure to dust levels.

The testing methodology for the collection of respirable and inhalable dust loads at each independent source of dust generation on a longwall must be broken down into individual tasks of the dust collection process. Figure 2 shows the tasks and steps in the Dust Mitigation Efficiency (DME) model to be undertaken during the testing process. The first stage in this methodology is to determine monitor placement on each of the independent sources of dust generation. In each location, two monitors and two heads will be used to sample both respirable and inhalable dust loads.

58 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Identify and Record Engineering Controls

Determine Pump and Head Placement

or a positive number an increase in dust when installed engineering controls are operating. Once the samples were collected from the mine site, the sampling heads were weighted in the laboratory using an ultraâ&#x20AC;?precision balance (METTLER TOLEDO XP205DR - EL. ANALYTICAL BALANCE) connected to a computer which automatically records the data. Figure 3 shows the laboratory facility for dust sample weight processing.

Establish Benchmark Dust Load Production

Figure 2: Dust monitoring methodology flowchart DME is calculated to determine the efficiency of installed controls as a percentage of a tested dust load benchmark. Two tests are undertaken, one as a benchmark with no engineering controls operating to mitigate the produced dust, and the second test performed with all engineering controls operating. The difference between controls off and controls on determines the DME which is a quantifiable number that shows the percentage decrease, or in some cases increase, of dust loads produced at independent sources of dust generation and how effective the installed controls are at mitigating this produced dust. The calculation process to determine the respirable and inhalable DME is as follows:

Figure 3: Lab system for dust sample weight

FIELD APPLICATIONS Field trials were undertaken at five Australian longwalls producing a total of 190 respirable dust samples and 170 inhalable dust samples. Two mines sampled were in the Wollongong coal fields, two were in the Hunter coalfields and one was in the Bowen Basin. Figure 4 details the average mg/ tonne of respirable dust produced during the cutting cycle with no engineering controls operating at each of the known sources of dust generation for each of the mines sampled. The average mg/tonne was calculated by adding together each of the collected samples and dividing the number by the amount of samples collected. This average was then used to compare the average of each sample collected at that location for each of the 15 tests undertaken at the five mines

where: DME is the Dust Mitigation Efficiency, %; n represents the location of monitors and heads; wef is the weight of final efficiency test filter used, mg; wei is the weight of initial efficiency test filter unladen, mg; Te is the tonnes cut for efficiency testing, t. wbf is the weight of final benchmark test filter used, mg; wbi is the weight of initial benchmark test filter unladen, mg; Tb is tonnes cut for benchmark testing, t; The DME is presented as a percentage (%) change in the mg/ tonne produced at each individual source of dust generation sampled. This can be either a positive or negative number, with the negative number representing a reduction in dust

Field applications of the new dust monitoring methodology have successfully identified the most efficient installed engineering controls operating at individual sources of respirable and inhalable dust generation on operating longwalls in Australia. By installing the best practice engineering controls, operators are in a better position to ensure compliance to regulatory standards for exposure levels and most importantly, they are ensuring minimum risk to worker health by ensuring they are mitigating the most respirable and inhalable dust possible from the mining environment.

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RESEARCH

Quantify Installed Engineering Control Dust Mitigation Efficiency (DME)

Improved Dust Control on Longwalls Using a New Water Mist Venturi System Key researchers: Ting Ren and Zhongwei Wang Research Partners: CSIRO and Tecpro Australia Funding Sources: Australian Coal Association Research Program

INTRODUCTION

RESEARCH

Advances in modern longwall (LW) technology have resulted in high production faces with high powered chocks and shearers that can advance at faster rates. As longwall chocks advance, crushed roof coal and or rock can fall from the top of the chock canopy into the face ventilation airflow. Real-time respirable dust survey conducted showed that as the maingate (MG) chocks advanced immediately after a shearer pass, the registered dust levels at the shearer MG operator’s position increased significantly, accounting for about 47.8% of total longwall dust produced during the cutting cycle. Much of these respirable dust particles generated from MG chock movements and the beam stage loader/crusher (BSL) dispersed quickly into the longwall face due to the high velocities of air ventilation, thereby contributing significantly to higher dust levels. Hence controlling and suppressing the dust emanating from the advancement of MG chocks (1-5) is considered to be one of the critical activities to reduce the dust levels in LW face mining, as shown in Figure 1. Traditionally, water spray systems were used to suppress dust and are still used in many mines, however, these efforts to suppress dust have met with varying degrees of success. This is largely due to the difficulty in removing small dust particles (< 10 microns) as they quickly drift away in the air and the probability of collision with large water spray particles is greatly reduced.

Figure 1. Dust survey on a longwall showing MG Chocks (1-5) advance dust Historically water sprinklers/hoses have been used for dust control on longwalls to suppress the dust particles before they become airborne. The fundamental principles for dust suppression is to allow the water drops to collide with dust particles in the air, forming heavy agglomerates of dust and water, resulting in a “settling out” of the airborne dust. However, conventional hydraulic water sprays are not effective on respirable dust. With typical diameters of 200600 µm sprays, the droplets are much larger than the dust particles they are attempting to suppress. Water drops that are too large will not collide with the finest, most hazardous dust particles smaller than 10µm. Airborne water droplets and dust particle attraction is most likely to occur when the droplets and dust particles are in similar size.

This project aims to develop and test a new type of venturi system based on ultra‐fine water mist technology to reduce respirable dust contamination on medium and thick seam longwall faces, particularly those dust particles from the advancement of MG chocks and the intake ventilation passing the BSL. The system is designed to perform two main dust control functions: • To produce uniformly‐distributed ultra‐fine water droplets (1‐10 micron) for encapsulating and trapping a high proportion of the respirable dust particles before they become airborne and reach the walkway area; and • To induce a controlled volume of water‐mist airflow with sufficient momentum for diverting and streamlining respirable dust clouds off the walkway area along the face.

DESIGN OF A WATER MIST BASED VENTURI SYSTEM Dust suppression systems using ultra fine water mist technology have recently been tested in underground coal mines and demonstrated promising results. In Australia, a simple dust suppression system using ultrasonic atomisers has been installed at the MG transfer point at Broadmeadow and excellent dust control result has been observed. In South Africa, a fogger system using water mist technology has been investigated at Thandeka and Twistdraai as water curtains on the intake airway and transfer points. Field results prove that the system was highly effective by reducing dust concentrations by 96% during the test periods. In this project, dust suppression systems using ultra fine water mist technology, were used for suppressing the respirable dust. A new water mist based venturi system was developed for the purpose of suppressing respirable dust. This unit is powered by compressed air and water using an ultrasonic nozzle (MAL 1300 B1) embedded in the venturi body. These ultrasonic nozzles are capable of producing ultra fine water mist with droplet sizes ranging from 1 to 100 microns. As a result of the small droplet sizes, these particles collide more effectively with respirable dust particles, facilitating the reduction of respirable dust concentration. In order to optimise design configurations for optimum spray coverage and spray distances, several design assemblies were considered, namely, standard body rear fit, standard body front fit, shortened body rear fit, shortened body front fit, shortened body rear fit with extension of 1-40mm, and shortened body rear fit with extensions of 2-50mm and 3 -65mm. In our experimental design, two different ultrasonic nozzles were used, namely MAL-1300-B1 and MAD-1131-B1. The air pressure, air volume, water pressure, water flow rate, air induction velocity and air induction volume were varied and the water mist velocity and spray distance were monitored to determine the best optimal values. Further relative positioning of the nozzle within the venturi system was varied to minimise water droplets hitting the venturi body. After rigorous laboratory tests, the results indicated that the nozzle MAL-1300-B1 performed better than the MAD-1131-B1, and 70 mm (diameter) x 143 mm (length) venturi was capable of producing an optimum spray coverage and spray distance over 10 m. Further tests showed that a combination of air supply at 6 bar and water at 4 bar produced the optimum water mist thrust with inducted air velocity over 8 m/s. Water consumption for these nozzles was about 2 L/min in for a single unit. These optimised parameters were then considered for use in underground field trials.

60 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

locations. The operating conditions of sprays with the best mitigation performance may vary according to the source of dust. To achieve an overall good mitigation effect, it is suggested that sprays in the face should be operated at 20o down and tilted 45o along face; sprays on the AFC/BSL spill plate should be operated at 30o down and 20o along face.

20° down and titled 45° along face

30° down and titled 20° along face Figure 4: CFD modelling of venturi unit

Figure 2: Water mist based venturi units for dust suppression in longwall face

CFD MODELLING OF AIRFLOW AND DUST PATTERNS

Field trials were conducted at two mines, Moranbah North in QLD and Metropolitan Colliery in NSW. Figure 5shows the venturi units attached to the canopy of a longwall chock before being dispatched to the underground longwall face, and during field trials underground.

Computational Fluid Dynamics (CFD) has proved to be capable of investigating a series of factor affecting the behaviour of longwall dust, such as the impact of ventilation, cutting sequence and local geological conditions. CFD has also been used for parametric studies, probing into the best performance of various dust control strategies. Work in CFD modelling of dust problems has demonstrated that this method has advantages for an improved understanding of air flow fields and dust behaviour in a longwall face with the application of visualization techniques. In addition to the improved knowledge of airflow/respirable dust dispersion patterns on longwall faces, the study focused on dust mitigation at the MG corner of a longwall face. Figure 3 shows the use of CFD modelling of dust flow pattern in a typical longwall face.

Figure 3: CFD modelling of longwall dust In this study, CFD models are used to study the face ventilation pattern and associated dust particle dispersion patterns with and without the use of venturi units at different

Figure 5: Field trials of the water mist venturi unit

2013 – 2014 ANNUAL REPORT 61

RESEARCH

FIELD DEMONSTRATIONS

Three venturi units were placed at chock #6 in Moranbah North mine whereas at the Metropolitan mine, three venturies were placed in similar locations to those of Moranbah North plus an additional one was placed at the BSL. Real time dust measurement monitoring using a Personal Dust Monitor (PDM) and gravimetric samplers were used respectively to assess dust mitigation efficiency. The cyclone pumps for PDM and gravimetric samplers were calibrated at a flow rate of 2.2 L/min for the respirable heads and 2 L/min for the inhalable heads. This is in line with the standards such as AS2985 and AS3640. MAL-1300-B1 air and water supplied to these units were around 6 bar and 3.5 bar respectively, with a water consumption of 2 L/min in per unit (total of 6 L/min for 3 units). The induced airflow velocity at the outlet mouth of the venturi unit was around 8 m/s according the lab test results, thus having some momentum for diverting and streamlining respirable dust clouds from the walkway area along the face. The field trial results from these two mines are summarised below:

RESEARCH

At Moranbah North Mine, three venturies were attached at the canopy of chock #6 and the dust monitoring was carried out at chock #8 and shadowing shearer operators. Field dust monitoring data showed that respirable levels were reduced by 20-30% at chock #8; The dust monitoring at the operator position showed dust concentration reduction ranging from 8-31%. At Metropolitan Mine, three venturi units were installed at chock #6 and one unit at BSL. Field data showed that respirable dust was reduced by 7% at chock #2, 22.5% at chock #5, 27% at chock #8 and 7% at chock #15;. The venturi unit at the BSL reduced respirable dust by 12% at chock #2, 13% at chock #5, 5% at chock #8 and 9% at chock #15;

direct monitoring, in Proceedings of 8th Underground Coal Operators’ Conference (Eds: N Aziz and J Nemcik), 14 ‐ 15 February 2008, Wollongong, Australia. pp 143‐154. http:// ro.uow.edu.au/coal/14/. 5. Ren T and Balusu R, 2010. The use of CFD modelling as a tool for solving mining health and safety problems, in Proceedings of 10th Underground Coal Operators’ Conference (Eds: N Aziz and J Nemcik), 11‐12 Feb 2010, Wollongong, Australia. http://ro.uow.edu.au/coal/319/. 6. Rider, J P and Colinet, J F, 2006. Dust control on longwalls: assessment of the state of the art, In: Proceedings of the 11th U.S./North American Mine Ventilation Symposium (eds. Mutmansky JM and Ramani RV). University Park, PA, London, UK: Taylor and Francis Group June 5‐7, 2006, pp 225‐232. 7. Ting Ren, CFD Simulation and dust controls for hard rock mines, Hard Rock Mine Ventilation 2011, Perth, Western Australia. 8. Ting Ren, Graeme Cooper and Srinivasa Yarlagadda, Development of a water‐mist based venturi system for dust control from maingate chocks and BSL, 2011 Underground Coal Operators’ Conference, (Editors: N Aziz, B Kininmonth, J Nemcik and T Ren) Wollongong, NSW, Australia, February 10/11, pp 239‐49.

The combined effect of operating venturies at both BSL and chock spray showed a total reduction in respirable dust of 19% at chock #2, 35% at chock #-5, 32% at chock #8 and 16% at chock #15. These field trials demonstrated promising results with these ultra fine water mist technology. However the best mitigation performance may vary according to the source of dust and the operating conditions of sprays. The potential for the application of this technology in other areas of mining can be substantial particularly in underground coal mines and hard rock mines. Such units can also be deployed for dust mitigation in tunnelling surface stockpiling and mineral processing plants. Improved design and further trials are needed to improve its operation and dust mitigation performance.

REFERENCES 1. Brian Plush , Ting Ren and Naj Aziz, A critical evaluation of dust sampling methodologies in longwall mining in Australia and the USA, 2012 Underground Coal Operators’Conference, (Editors: N Aziz, B Kininmonth, J Nemcik and T Ren) Wollongong, NSW, Australia, February 16/17, pp 194‐202. 2. Brian Plush, Ting Ren, Ken Cram and Naj Aziz, Dust monitoring and control efficiency measurement in longwall mining, 2011 Underground Coal Operators’ Conference, (Editors: N Aziz, B Kininmonth, J Nemcik and T Ren) Wollongong, NSW, Australia, February 10/11, pp 231‐38. 3. Colinet, J F, Rider, J P, Listak J M, Organiscak, J A and Wolfe, A L, 2010. Best Practices for Dust Control in Coal Mining, NIOSH, Information Circular 9517.6) 4. Gillies S and Wu H W, 2008. Underground atmosphere real time personal respirable dust and diesel particulate matter

62 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Key Researchers: Naj Aziz and Jan Nemcik

INTRODUCTION Cable bolt usage in Australian coal mines is on the increase, because it is mostly used as a secondary support to supplement the primary support system for strata reinforcement. Several factors have contributed to the increase in cable bolt usage in mines; the most prominent of these are a better understanding of the principals of rock mechanics and strata control, and better management of difficult ground conditions. Reliance on Short Encapsulation Pull Testing (SEPT) of cable bolt cannot be considered as adequate for providing realistic answers to the credibility of the cable bolt installation in given ground condition. A number of papers have been reported on studies examining the load transfer and unscrewing characteristics of cable bolts (Tadolini, et al., 2012; Thomas, 2012, Aziz et al, 2014), and there have been significant variations in the cable bolt design to include both plain and indented cable bolts of different sizes and strand or wire configurations (Figure1). The increased variations in cable bolt configurations and designs have also generated deep interest in shear failure of tendons’. In situ studies in cable bolt shear are difficult to conduct, but can carried out in laboratory simulated conditions.

Testing of the cable bolt in shear using the double embedment assembly as recommended by the British Standard (BS 78612:2009) is an un-realistic approach. Guillotining of the cable tendon, leading to true shearing of the metal elements is not what occurs when a cable bolt is sheared across a rock joint. In reality the failure of the cable bolt in rock or composite material is a combination of both tensile and shear failure manifested with crushing of the rock or concrete surrounding the zone of the sheared plains, (Craig and Aziz, 2010). These findings were also demonstrated by numerical simulations in both rock bolts

CABLE BOLT DESCRIPTION Two cable bolts were tested. They were Super Strand 19 strand wires of construction designation (9 x 9 x 1) plain strand and spirally indented strand cable bolts. The cables were both 22 mm in diameter with the rope thread profiles being “Left Hand Lang’s Lay” construction type. Both cable bolts shown in Figure 1 consisted of an outer 5.5 mm diameter strand layer, overlying the middle 3 mm diameter wire strands. Both layers were wrapped around a single sold 7 mm diameter strand wire core. Table 1 show the specification of both cables Performace data

Plain strand

Indented strand

Ultimate yield load

495 kN (50 t)

425 kN (43 t)

Ultimate failure load

573 kN (58 t)

510 kN (52 t)

Bolt diameter

21.8 mm

Cross section area

312.9 mm2

277 mm2

Mass

2.482 kg/m

2.2 kg/m

Outer strand diameter

5.5 mm

Inner lay strand diameter

3.0mm

3.0 mm

Core strand diameter

7.0 mm

Table 1: – specification of Hilti Cable bolts a)

19 strand cross section

b) Indented cable

CONCRETE SAMPLES PREPARATION AND CABLE BOLT INSTALLATION Figure 2 shows a general layout of an assembled double shear apparatus with installed cable bolt. Each double shear testing process required three concrete blocks with two outer 300 mm side cubes and a central rectangular block 450 mm long. The casting of the concrete blocks for the test was carried out in the steel frame of the double shear apparatus. The UCS value of the concrete used in this study was 40 MPa, determined from testing the representative 100 mm diameter cylindrical concrete samples.

c) Plain strand cable Figure 1: Plain and indented cable bolt and cross-section view of 19 mm seal strand construction (Jalalifar, et al, 2006).

Figure 2: A schematic layout of the cable installation assembled in concrete blocks

2013 – 2014 ANNUAL REPORT 63

RESEARCH

Shear Strength Properties Of Plain And Indented Strand Cable Bolts Used For Ground Support In Mines

The installation of the cable bolt in a three pieces concrete mould was carried out using FB400 cable bolt grout. The cable bolt was inserted into the central hole of the assembled concrete blocks. A 60 t load cell was then mounted on one side of the protruding cable bolt using a barrel and wedge assembly. This was followed by the addition of the grout injection sleeve/and bolt tensioner assembled on the other side of the assembled double shear box, and was held in place using another barrel and wedge. The cable bolt was pretensioned to an axial load of 50 kN by a torque wrench prior to grouting. The assembled double shear box apparatus was then placed on a carrier base frame consisting of a parallel pair of rail track sections welded to a 35 mm thick steel plate. The whole assembly was mounted between the 600 x 600 mm loading plates of the 500 t compression testing machine as shown in Figure 3. The outer 300 mm side concrete cubes were seated on 75 mm high steel blocks, leaving the central 450 mm long block free to move vertically down during the shearing process. The rate of shearing of the double shear apparatus middle section was maintained constant at 1 mm/min for the 75 mm of vertical displacement. The rate of loading and displacement was monitored and simultaneously displayed visually on a PC monitor.

a) Indented strand cable bolt.

b) Plain strand

RESEARCH

Figure 4: shear load and axial load versus vertical travel of the central block of the loaded double shear assembly for (a) indented and (b) plain strand cable bolt.

Figure 3: Double shearing apparatus loaded in 500 t Avery compression testing machine

RESULTS AND ANALYSIS Figure 4 shows the applied shear load and axial load in each of indented and plain strand cable bolts versus the vertical displacement of the central concrete block of the double shear assembly. For the indented cable bolt test, the maximum vertical load was 904 kN, which occurred when the vertical travel of the central block reached approximately 52 mm. The maximum axial load developed at the cable bolt was 254 kN. Various shear load drops that occurred beyond the vertical displacement of 52 mm were due to individual cable strand failures (strand snap). The relatively larger shear load drop, post the 904 kN maximum

load, was likely due to the larger diameter (5.5 mm diameter) outer strand as well as the central core strand failures (7 mm diameter), while small drops are indicative of the small 3 mm diameter strand failure. It is interesting to note that the outer strand failures are also marked by drops in the axial load on the cable bolt, as monitored by the 60 t load cell. The number of visible sudden drops on the load displacement graph appears to be slightly less than the total number of the 19 failed strands. This is clearly evident from Figure 4a of the failed /snapped cable section as retrieved from dismantled blocks. Note that sudden drops at points A and B shown in Figure 4a are attributed to wedge and barrel settlement / adjustment during the early start of cable bolt shear loading. Characteristically, the snapped cable strand ends depict strand failures as a combination of tensile and shear failures as shown in Figure 5. This type of failure is likely to occur when the cable is sheared in a rock mass, which is a realistic failure occurrence and is the result of bending of the cable in the vicinity of the sheared plains where the concrete has crushed for a length of up to around 60 mm from the sheared joint plains as demonstrated in Figure 5b.

Figure 5: post shear view of the cable bending and snapped cable strands

64 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

The maximum applied shear load on the plain cable bolt of 1024 kN for vertical shear displacement of 72.5 mm was 13.8 % greater than the maximum shear load of 904 kN achieved from the indented strand cable. As can be seen in Table 1, the ultimate failure load of the plain strand cable bolt of 495 kN is 70 kN more than the tensile strength of the indented strand cable bolt, which is an increase in the ultimate strength of 16.5% in favour of the plain strand cable bolt. Thus, the reduction of 70 kN in the ultimate tensile strength of the indented cable bolt may explain the reason as why the cable failed at much lower sharing load. This reduction in the indented cable strength was subsequently verified by tensile strength testing of cable’s individual strands, which resulted in a drop in tensile strength of the indented strand by 10.0 %. Figures 6 shows typical profiles of load - elongation of both 5.5 mm plain and indent strands of cable bolts. The machining of the outer strands to create indentation may have a detrimental bearing on the strand strength, contributing to reduce tensile and shear strength of the cable bolt. Therefore, it is fair to conclude that the strand manipulation for producing indentation may have affected the ultimate tensile strength of the intended cable bolt, as the overall cross sectional area of the indented cable bolt was reduced by 13%.

REFERENCES British Standard BS 7861-2, 2009. Strata reinforcement support system components in coal mines Part 2. Specification for flexible systems for roof reinforcement. Craig, P and Aziz, N, 2010. Shear testing of 28 mm Hollow Strand “TG” Cable Bolt, in proc.,10th Underground Coal operators Conference, Wollongong, February 11/12, pp171179. Goris, J H, Martin, L A and Curtin, R P (1996). Shear behaviour of cable bolt supports in horizontal, bedded deposits, in proc., 15th Int. Conf. on Ground Control in Mining, Colorado school of Mines , Golden, Colorado, August 13-15, pp511521, (Eds: Ozdemir, Hanna, Haramy and Peng] Jalalifar, H., Aziz, N., and M Hadi. (2006). The effect of surface profile, rock strength and pretension load on bending behaviour of fully grouted bolts, Journal of geotechnical and geological engineering, Vol 24, pp 1203-1227. Tadolini C S, Tinsly, J and McDonnell, J P (2012). The next generation of cable bolts for improved ground control, in proc.31st Int. Conf. on Ground Control in Mining, ICGCM, 7 p,

Aziz, N, Heemann, K, Nemcik J. and Mayer, S (2014). Shear strength properties of Hilti plain and indented strand cable bolts, in proc. Coal Operators Conf.(Coal2014), Wollongong, February 12-14, , pp156-162 (Eds. N Aziz, and B Kininmonth

Figure 6: Tensile load / elongation profiles of both plain and indent 5.5 mm strands of cable bolts.

SUMMARY The shearing strength of the cable bolt is influenced by the outer strand indentation, with the reduction in shearing strength by around 13.8%. However, the tensile strength failure of the individual strand resulted in a strength reduction of 12.8 %. Thus, indentation of the cable bolt’s outer strand weakens the cable bolts tensile and shearing strength. • All strands of the indented cable bolt failed post peak shear load. No strand failures were observed in the plain strand cable bolt tested in shear. • All cable bolt strands failed in combined tensile and shear as demonstrated by the cup and cone failures of the failed cable section strands. • The use of the laboratory based double embedment assembly for shear test as recommended by British Standard BS 7961-2 2009 is not a realistic way of evaluating the shear strength of cable bolts in situ. • No cable rotation was detected in double shear testing of either plain or indented cable bolts.

2013 – 2014 ANNUAL REPORT 65

RESEARCH

Thomas, R, 2012. The load transfer properties of post groutable cable bolts used in the Australian coal industry, in proc., 31st Int. Conf. on Ground Control in Mining, Morgantown, WV, August, 10 P.

Simulation Of Fracture Propagation Mechanisms In Rock Key Researchers: Jan Nemcik and Gaetano Venticinque

INTRODUCTION

RESEARCH

The analysis and design of rock structures is important to ensure the stability and integrity of modern world infrastructure. In the field of rock mechanics, development and location of tensile fractures is relatively easy to predict yet the mechanism, speed and extent of shear fracture propagation remains poorly understood. This comes as a major shortcoming especially since the majority of failure through rock occurs in shear. This research aims to develop new mathematical and numerical theories and models to resolve the essential missing knowledge around fracture propagation in rock. The ongoing research concentrates on the static and dynamic load factors governing fracture propagation in both the isotropic and anisotropic rocks. Several theories have been successfully tested using the computational Fast Lagrangian Analysis Continua (FLAC) numerical method (Itasca 2005) to simulate fracture propagation observed in laboratory rock specimens. Up to date numerical simulations reveal remarkable agreement between the theoretical fracture propagation and laboratory tests. We aim to concentrate and develop new theories based mainly on pure science (physics) to simulate fracture behaviour as it occurs in nature. New findings are constantly incorporated into the fracture software to improve the current model. The proposed new fracture model has been trialled in large variety of rock types and geometries under different loading conditions from which some are briefly discussed here.

NUMERICAL MODELLING

Figure 1: Comparison of the FLAC capabilities to model rock failure, the newly developed rock fracture model and failure of the isotropic marble rock tested in the laboratory

A FLAC model driven by the FISH fracture subroutine was constructed to simulate uniaxial compression failure in the isotropic rock. Capability of the existing model can be seen in Figure 1 where the marble rock loaded to failure was simulated in FLAC. The first model (a) shows unrealistic failure behaviour when using the standard Mohr-Coulomb failure criterion, which is available commercially. The second model (c) that incorporates the subroutine with the proposed fracture mechanism showing a more realistic type of failure closely matching the laboratory test results. Anisotropic rocks were modelled in FLAC with an isotropic continuum exhibiting reduced strength properties in the direction of existing joints. The anisotropy was introduced by altering FLAC joint properties to include weakly oriented joints at 40째 to the sample vertical axis. The geometry of the modelled cylindrical rock core can be seen in Figure 2. The modelled fracture distribution is closely aligned with the expected shear failure along weakly bound joints oriented at 40째. The modelled compressive strength values of the jointed samples matched the theoretical values calculated using equations derived by Jaeger and Cook (1971) for anisotropic rock strength.

Figure 2: New approach of fracture modelling in FLAC showing fracture propagation in anisotropic rock

66 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

MODELLING OF ROCK SLOPES

REFERENCES

A numerical model of rock slope was constructed in FLAC to test the new fracture subroutine. The FLAC model used in these simulations reflect a hypothetical layered rock slope mined at an angle of 60Â°. The strata consisted of two coal seams overlain by weak claystone and weathered sandstone units. During progressive mining simulation In situ stresses were equalised through incremental excavations of 1m strips. Fractures and localised failures were produced independently throughout this entire process. The modelled failure is depicted in Figure 3.

Itasca Consulting Group, I., 2005. FLAC - Fast Lagrangian Analysis of Continua. Version 5.0, User Manual. Minneapolis.

Jaeger, J.C. and N.G.W. Cook, 1971. Fundamentals of Rock Mechanics, Chapman and Hall, London. Venticinque, G A, 2013. Advanced Numerical Modelling of Fracture Propagation in Rock, Honours Thesis, Department of Engineering, School of Mining Engineering, University of Wollongong.

3. Venticinque, G A, Nemcik, J A and Ren, T, 2013. New fracture model for the prediction of longwall caving characteristics, 6th International Symposium on Green Mining (ISGM), 2013. University of Wollongong, pp 63-68. 4. Venticinque, G and Nemcik J, 2014. New fracture models for the progressive failure of rock slopes, In Proceedings Coal operators conference, Wollongong, February, 12-14, pp82- 88 (http://ro.uow.edu.au/coal/501/)

Figure 3: New approach of fracture modelling in FLAC showing rock slope failure in bedded rock

RESEARCH

SUMMARY The newly developed fracture model detailed in thesis by Venticinque, et al., (2013,), Venticinque (2013) and Gaetano Venticinque and Jan Nemcik (2014) publications is offering a new approach to simulate various fracture types including progressive development of multiple fracture zones within rock structures. As demonstrated through the strength analysis of different rock samples and slopes, such analysis would not have been possible using any previous conventional modelling approach. The model has demonstrated the ability to simulate fracture propagation in various isotropic or anisotropic rock types and unlimited geometries. Through continued validation of other complex problems the new model is envisaged to offer safer and more realistic predictions of rock failure for the civil, mining and other geotechnical industries.

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 67

Polymer-Based Alternative to Steel Mesh for Coal Mine Strata Reinforcement

now reflect industry practice, has resulted in development of polymers of comparable tensile strength and hydrophobicity to that now being achieved in industry. Table 0: Tensile and flexural strength of developed polymers

Key Researchers: Ian Porter, Jan Nemcik and Ernest Baafi Funding Source: Australian Coal Association Research Program

INTRODUCTION The project seeks to identify novel polymer-based systems for skin reinforcement and confinement in longwall coal mine roadways as an alternative to the continued use of steel mesh for roof and rib support. The objective of the research is to develop a skin confinement system, ToughSkin that can be remotely applied thereby facilitating automation of the roadway development process and allowing operational personnel to be removed from the immediate face area. It is envisaged that the application system will be fully automated, and will enable higher rates of development to be achieved. The long-term objective is to develop a system that: • provides an effective skin reinforcement and confinement measure, yet is flexible and adaptable; • requires minimal human intervention in its supply and installation; • removes personnel from the immediate face area;

RESEARCH

• is compatible with Australian underground coal mine environments; • is safe to use and apply; • enables the mining process to advance continuously; • enables higher roadway development rates to be achieved, and • is cost effective.

MAIN FINDINGS Research has been able to demonstrate that polymers can be formulated with equal or superior tensile strength to steel mesh, albeit that some of the developed polymers may have properties which could preclude their adoption at this stage of the research. The tensile strength of steel roof mesh has been determined to be 500-600 MPa which, based on a 5 mm mesh strand at 100 mm centres, is equivalent to 20-30 MPa, whereaspolymers have been developed with the tensile strengths demonstrated in Table 1. It can be seen from Table 1 that the tensile strength of unreinforced polymers has improved beyond the levels initially reported for both styrene and NVP cross-linked systems. Improved process methodology and thermodynamic control also resulted in improved tensile strength in PE-7, methodology and controls which were subsequently utilised for the development of a new polymer formulation which also addressed chemical and water degradation (hydrolytic) as found in PE-7. With reformulation of the polyester (PE-X), not only was hydrophobicity improved but tensile strength was also increased. Further increases in tensile strength were then achieved by utilising selected monomers either singularly or as blends (e.g. 4-tert-butylstyrene, and a 50/50 blend of TEGDVE/4-tert-butylstyrene).The improvements in process methodology and thermodynamic control achieved, which

Polymer

Monomer

Unreinforced Tensile Strength (MPa)1

Control (I) Minova PE

Styrene

16.7

Minova PE

NVP

14.5

PE-7

TEGDVE

5.7

PE-7

TEGDVE (improved process methodology and thermodynamic control)

15.2

Control (II) PE-X

Styrene

24.5

PE-X

TEGDVE (with modified polyester)

18.2

PE-X

4-tert-butylstyrene

PE-X

50% TEGDVE / 50% 4-tert-butylstyrene

PE-NP1

Nuplex (built in monomer)

29.6

The behaviour of steel mesh was studied extensively in order to determine the control parameters for development of a polymeric confinement system. While it was determined that the maximum load bearing capacity of steel mesh was 45 kN under a concentrated load, and more than 70 kN under a distributed load (failure load was not reached), the behaviour of steel mesh under load could not be readily quantified. However, it has been shown that under the same loading regime steel mesh deforms substantially more than any of the polymer composites tested. The stiffer support system provided by the polymer, particularly at the time of application, helps the immediate roof maintain its integrity, thus assisting the self-supporting capacity of the roof. Although it may not be possible to fully define the behaviour of mesh in situ, it is believed that large scale tests of both steel mesh and the polymer skin supplemented with numerical modelling will assist in the future development of polymer based reinforcement systems by advising on the fundamental differences between the reinforcing mechanisms of steel mesh and polymeric skin confinement systems. Geotechnical studies in fact demonstrated that a polymeric skin confinement system had enhanced properties and qualities beyond that of steel mesh, with the polymeric skin acting as a composite with the underlying strata to prevent or arrest crack propagation. This ability of the composite to arrest crack propagation is due to the polymers ability to adhere to the substrate and cause the stress concentration at the crack tip to be transferred elsewhere. Further, other research found that the applied thickness of reinforced polymer (PE-7) could be reduced from the nominal 5 mm used in mechanical and geomechanical test regimes to a thickness of 3 mm without adversely affecting the tensile strength of the polymer. This reduction in skin thickness is likely to have a significant cost benefit if it can be replicated with other polymers. Tests to determine the optimum shape and size of the bolt plate were not conclusive, however, the initial hypothesis that

68 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

the polymer would require a large circular plate in order to avoid stress concentrations in the polymer was refuted and it was shown that a square plate would perform equal to that of a circular plate of similar size. What did become obvious was the impact of the plate’s rigidity, a plate that was too flexible and the stress will concentrate around the collar, too stiff and the stress will concentrate elsewhere. It was successfully demonstrated that the polymeric skin confinement product could be sprayed onto a simulated “roof” and “rib” without sag. In addition, • Product viscosity challenges to achieve a spray-able product that does not sag has been achieved by a combination of: 1) reducing base viscosity for pumping and spraying by resin synthesis optimisation, formula compounding techniques, selection of a low viscosity antistatic additive and application at elevated temperature; and 2) maximising set up viscosity by addition of rheology modifying agents and reinforcing fibres, and by virtue of the rapid cooling of the atomised product outside the gun and prior to reaching the sprayed surface. • Airless atomisation of Prototype A1 has been demonstrated with an evenly distributed flat fan spray pattern and consistent droplet size suited to external mixing. • External mixing with air-assist-sprayed Prototype B2 has demonstrated sprayed curing. • Reinforcing fibre application for a 3-part sprayed system has been demonstrated

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• Good bonding onto cement fibre has been demonstrated with suitable surface finish and very low porosity.

CONCLUDING REMARKS While the primary focus for development of ToughSkin has been to improve gateroad development rates it is evident that the system could also be utilised in bord and pillar mining systems, including cut and flit operations. There is also potential for ToughSkin to be utilised in the underground metalliferous sector as a replacement for shotcrete (mines typically apply 25-50 mm of shotcrete immediately after faces are blasted, with the faces then being bolted after the initial cure of the shotcrete has been achieved, a delay of some 1-2 hours). Similarly, ToughSkin could be used in the civil tunnelling sector for skin confinement or to seal against water ingress. Expressions of interest have been received from both sectors at industry conferences, with a number of chemical companies/formulators/suppliers expressing interest in manufacturing the final product.

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The Modelling of Roadway Development to Support Longwall Mining Key Researchers: Ernest Baafi and Ian Porter Funding Source: Australian Coal Association Research Program

BACKGROUND Longwall mining is recognised as an efficient and cost effective means of extracting coal from underground seams. However, effective longwall operation requires that roadway development must be kept ahead of the longwall advance. Simulation Modelling Services Pty Ltd (SMS) and the University of Wollongong have collaborated on the Australian Coal Association Research Program (ACARP) Project C17019. The result of this collaboration is a modelling system able to be used to review and explore options related to gate road development.

RESEARCH

The roadway development process requires the coordination of a range of mining equipment operating in challenging working conditions. For efficient roadway development operations to be possible the equipment used must be matched to the local environment and mining conditions. A number of options can exist for laying out and configuring any roadway development system. However, evaluating the likely relative performance of these options can be difficult. The result of this project is a dynamic simulation system referred to as RoadSIM. RoadSIM is a computer simulation that has been specifically developed to model roadway development operations in a typical 2 heading configuration. Through RoadSIM it is possible to investigate the impact changes in equipment configuration and/or operational procedures may have on performance indicators such as development rates, time to complete a pillar or equipment utilisation.

PROJECT OBJECTIVES This project aimed at providing tools to assist in improving the overall productivity of roadway development in the Australian coal industry. In particular, one of the outcomes of the project was to develop a modelling system capable of being used to assess roadway development options. The system was intended to allow professionals that may have only a general knowledge of simulation to be able to build, customise and use simulation models of a range of roadway development processes. The computer models were to be capable of being used to analyse current roadway development operations as well as being able to assess the impact on performance of potential changes in procedures and/or equipment.

PROJECT STAGES The development of the modelling system involved a number of stages. These included: • appreciation of the roadway development process; • collection of operating data; • development of a modelling system; and • validation of the modelling system. To achieve the desired objectives a computer simulation modelling system has been developed that utilises the technique of animated discrete event simulation. Discrete event simulation provides a proven technique to study the interaction between components of a complex system. It is especially well suited to evaluate the performance of roadway development operations. In addition, the simulation technology has the ability to explicitly allow for the randomness/variability inherent in the mining operation. For example, modelling can consider variability in shuttle car tramming times, loading and discharging times, the time to complete support operations and process availability. The system has been developed using “industry standard” simulation software (Arena) so that it may be expanded in scope and detail if required. The computer models built using RoadSIM can be used to analyse current roadway development operations as well as assess the impact on performance of potential changes in procedures and/or equipment.

ROADSIM SYSTEM CAPABILITY RoadSIM is able to simulate two heading roadway development configurations, including all operations from boot-end to development face. The simulation provides an animated display plus a range of output statistics that can be used to assess the performance of roadway development options. The statistics reported provide information on: • expected development rates (m/operating hour); • time to complete a pillar; • utilisation of continuous miners.

70 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

The system is capable of considering aspects of roadway development such as: Pillar Layout • pillar length; • cut-through length; • cut-through to Boot End distance; • heading width and height. Continuous Miner Operation • number of continuous miners (CM) in the model; • miner types, either a Miner-Bolter (ie mining and bolting are executed sequentially) or a Bolter-Miner (ie mining and bolting are executed in parallel); • the sequence followed by the miner/s in each heading. Shuttle Car Operation • number of cars in the model; • route followed by each car, note each car can only service a single miner; • shuttle car capacity, loading and discharge rates and wheeling velocity. Face Operations

Figure 1: Impact of support cycle on development rate Typically RoadSIM would be used to consider the impact on development rates of aspects of operations such as: • pillar and cut through dimensions; • number of shuttle cars in use; • cycle times for cutting and loading at the development face; • cycle times for bolting; • shuttle car tramming speeds; • cycle time for discharge of a shuttle car; • delays effecting out bye services; and • delays effecting face operations.

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• standard face operations are included (e.g. stone dusting, supplying miner, installing vent tubes); • other face operations (eg cutting breakaway, niche, etc). Support Operations • time required to complete support operations. Boot End and Out-bye Operations • Boot End with or without bunker; • bunker capacity and feed rate on the out-bye conveyor. Availability • patterns of weekly operating shifts and planned maintenance. • unplanned delays including duration and mean time between failure.

EVALUATING ROADWAY DEVELOPMENT OPTIONS Once the model is validated for a specific site it can be used to explore options by varying the input parameters. The model is setup for a “what if” type of analysis (Figure 1). This allows the user to put forward alternate equipment/operations and predict the likely impact on production rates.

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RESEARCH

Publications Abousnina, R. M. & Nghiem, L. D. (2014). Removal of dissolved organics from produced water by forward osmosis. Desalination and Water Treatment, 52 (4-6), 570-579. Abousnina, R. M., Nghiem, L. D. & Bundschuh, J. (2014). Comparison between oily and coal seam gas produced water with respet to quantity, characteritics amd treatment technologies: a review. Desalination and Water Treatment, Online First Alfadhli, I., Yang, S. & Sivakumar, M. (2014). The prediction of turbulence intensities in unsteady flow. 35th Hydrology and Water Resources Symposium (HWRS 2014) (pp. 860-866). Australia: Engineers Australia. Alfadhli, I., Yang, S. & Sivakumar, M. (2014). Why the observed turbulence intensities in non-uniform flow deviate from those in uniform flow?. 35th Hydrology and Water Resources Symposium (HWRS 2014) (pp. 525-532). Australia: Engineers Australia. Athukorala, R. Manori., Indraratna, B. & Vinod, J. (2014). A disturbed state concept inspired constitutive model for lignosulfonate treated silty sand. International Journal of Geomechanics, In Press Aziz, N., Craig, P., Nemcik, J. & Hai, F. (2014). Rock bolt corrosion - an experimental study. Transactions of the Institutions of Mining and Metallurgy, Section A: Mining Technology, 123 (2), 69-77.

Aziz, N., Florentin, R., Zhang, L., Ren, T. & Black, D. John. (2014). Enhancement of coal seam gas by nitrogen injection - a laboratory study. 10th International Mine Ventilation Congress (pp. 41-46). Aziz, N., Heemann, K., Nemcik, J. & Mayer, S. (2014). Shear strength properties of Hilti plain and indented strand cable bolts. 2014 Coal Operators Conference (pp. 156-162). Australia: University of Wollongong. Aziz, N., Nemcik, J., Ma, S., Field, S., Hillyer, J. & Moslemi, A. (2014). Evaluation on load transfer along the length of fully encapsulated rock bolts, based on installation parameters. Sixth International Symposium, High Performance Mining (pp. 221-230). Aziz, N., Nemcik, J., Mirzaghorbanali, A., Foldi, S., Joyce, D., Moslemi, A., Ghojavand, H., Ma, S., Li, X. & Rasekh, H. (2014). Suggested methods for the preparation and testing of various properties of resins and grouts. 14th Coal Operators Conference (pp. 163-176). Australia: University of Wollongong. Bahrami, S., Ardejani, F. Doulati., Aslani, S. & Baafi, E. (2014). Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran. Environmental Monitoring and Assessment, 186 (12), 85738585. Basack, S. & Sen, S. (2014). Numerical solution of single pile subjected to simultaneous torsional and axial loads. International Journal Of Geomechanics, 14 (4),

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Chu, J., Indraratna, B., Yan, S. & Rujikiatkamjorn, C. (2014). Overview of preloading methods for soil improvement. Proceedings of the Institution of Civil Engineers: Ground Improvement, 167 (3), 173-185.

Cai, D., Baafi, E. & Porter, I. (2014). Shuttle car network for roadway development. 2014 SME Annual Meeting & Exhibition: Leadership in Uncertain Times (pp. 1-4). United States: Society for Mining, Metallurgy & Exploration.

Clements, D. D. A. & Teh, L. H. (2014). Closure to “Active shear planes of bolted connections failing in block shear” by Drew D. A. Clements and Lip H. Teh. Journal of Structural Engineering, 140 (2), 07013002-1-07013002-2.

Cao, C., Ren, T. X. & Cook, C. D. (2014). Introducing aggregate into grouting material and its influence on load transfer of the rock bolting system. International Journal of Mining Science and Technology, 24 (3), 325-328.

Craig, P., Aziz, N., Nemcik, J. & Moslemi, A. (2014). Evalualting methods of underground short encapsulation pull testing in Australian coal mines. 2014 Coal Operators Conference (pp. 109-117). Australia: University of Wollongong.

Cao, C., Ren, T., Cook, C. & Cao, Y. (2014). Analytical approach in optimising selection of rebar bolts in preventing rock bolting failure. International Journal of Rock Mechanics and Mining Sciences, 72 16-25.

Dai, Z., Chen, Y., Zheng, G. & Guo, W. (2014). Numerical analysis on the mechanism of bamboo soil nails and bamboo piles in rows for retaining deep foundation pit. Geotechnical Special Publication (pp. 720-730).

Chai, J., Carter, J. P. & Liu, M. D. (2014). Methods of vacuum consolidation and their deformation analyses. Proceedings of the ICE - Ground Improvement, 167 (1), 35-46.

Dai, Z., Fan, X. & Lu, C. (2014). Numerical analysis of stability of highway embankments and karst cave roofs in karst region. Yantu Lixue/Rock and Soil Mechanics, 35 (SUPPL.1), 382-390.

Chen, C. & McDowell, G. R. (2014). An investigation of the dynamic behaviour of track transition zones using discrete element modelling. Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit, ONLINE FIRST

Dang, H. Q., Nghiem, L. D. & Price, W. E. (2014). Factors governing the rejection of trace organic contaminants by nanofiltration and reverse osmosis membranes. Desalination and Water Treatment, 52 (4-6), 589-599.

Chen, C., McDowell, G. & Thom, N. H. (2014). Investigating geogrid-reinforced ballast: Experimental pull-out tests and discrete element modelling. Soils and Foundations, 54 (1), 1-11.

Dang, H. Quang., Price, W. E. & Nghiem, L. Duc. (2014). The effects of feed solution temperature on pore size and trace organic contaminant rejection by the nanofiltration membrane NF270. Separation and Purification Technology, 125 (April), 43-51.

Chen, H., Cheng, Y., Ren, T., Zhou, H. & Liu, Q. (2014). Permeability distribution characteristics of protected coal seams during unloading of the coal body. International Journal of Rock Mechanics and Mining Sciences, 71 105-116.

Duangkhae, S., Bergado, D. T., Baral, P. & Ocay, B. T. (2014). Analyses of reinforced embankment on soft and hard foundations. Proceedings of the Institution of Civil Engineers: Ground Improvement, 167 (1), 2-23.

Chen, Q., Indraratna, B., Carter, J. & Rujikiatkamjorn, C. (2014). A theoretical and experimental study on the behaviour of lignosulfonate-treated sandy silt. Computers and Geotechnics, 61 316-327.

Fatahi, B., Khabbaz, H. & Indraratna, B. (2014). Modelling of unsaturated ground behaviour influenced by vegetation transpiration. Geomechanics and Geoengineering: an international journal, 9 (3), 187-207.

Chen, Q., Xiong, H. & Gao, G. (2014). Experimental study on properties of seismic loading and their influence on seismic compression in sands. Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering, 36 (8), 1483-1489.

Fernando, D., Yu, T. & Teng, J. G. (2014). Behavior of CFRP laminates bonded to a steel substrate using a ductile adhesive. Journal of Composites for Construction, 18 (2), 04013040-1-04013040-10.

Chiaro, G., Indraratna, B. & Tasalloti, S. (2014). Predicting the behaviour of coal wash and steel slag mixtures under triaxial conditions. Canadian Geotechnical Journal, Online First

Fujioka, T., Khan, S. J., McDonald, J. A. & Nghiem, L. D. (2014). Nanofiltration of trace organic chemicals: a comparison between ceramic and polymeric membrane. Separation and Purification Technology, 136 (November), 258264.

Chiaro, G., Indraratna, B., Tasalloti, S. Ali. & Rujikiatkamjorn, C. (2014). Optimisation of coal wash¿slag blend as a structural fill. Proceedings of the Institution of Civil Engineers: Ground Improvement, Online First 1-12.

Fujioka, T., Khan, S. J., McDonald, J. A. & Nghiem, L. D. (2014). Ozonation of N-nitrosamines in the reverse osmosis concentrate from water recycling applications. Ozone: Science and Engineering, 36 (2), 174-180.

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Black, D. John. & Aziz, N. (2014). Changes in gas composition during coal seam drainage and laboratory testing. 14th Coal Operators’ Conference (pp. 252-265). Australia: University of Wollongong.

Fujioka, T., Khan, S. J., McDonald, J. A. & Nghiem, L. D. (2014). Rejection of trace organic chemicals by a hollow fibre cellulose triacetate reverse osmosis membrane. Desalination, Online First

Hadi, M. N. S. & Uz, M. (2014). Investigating the optimal passive and active vibration controls of adjacent buildings based on performance indices using genetic algorithms. Engineering Optimization, Online First 2-22.

Fujioka, T., Khan, S. J., McDonald, J. A., Roux, A., Poussade, Y., Drewes, J. E. & Nghiem, L. D. (2014). Modelling the rejection of N-nitrosamines by a spiral-wound reverse osmosis system: mathematical model development and validation. Journal of Membrane Science, 454 (March), 212-219.

Hai, F. Ibney., Nghiem, L., Khan, S., Price, W. & Yamamoto, K. (2014). Wastewater reuse: removal of emerging trace organic contaminants (TrOC). In F. Ibney. Hai, K. Yamamoto & C. Lee (Eds.), Membrane Biological Reactors: Theory, Modeling, Design, Management and Applications to Wastewater Reuse (pp. 165-205). United Kingdom: IWA Publishing.

Fujioka, T., Khan, S., McDonald, J., Roux, A., Poussade, Y., Drewes, J. & Nghiem, L. (2014). N-nitrosamine rejection by reverse osmosis: Effects of membrane exposure to chemical cleaning reagents. Desalination, 343 (June), 60-66. Fujioka, T., Tu, K. L., Khan, S., McDonald, J., Roux, A., Poussade, Y., Drewes, J. & Nghiem, L. (2014). Rejection of small solutes by reverse osmosis membranes for water reuse applications: A pilot-scale study. Desalination, 350 (October), 28-34. Ganesalingam, D., Read, W. & Sivakugan, N. (2014). Radial consolidation of soil layer under truncated cone fill. Environmental Geotechnics, Online first

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Gao, W., Liao, B. & Hai, F. I. (2014). Anaerobic MBRs. In F. Ibney. Hai, K. Yamamoto & C. Lee (Eds.), Membrane Biological Reactors: Theory, Modeling, Design, Management and Applications to Wastewater Reuse (pp. 335-377). United Kingdom: IWA Publishing. Gilbert, B. P., Teh, L. H., Badet, R. X. & Rasmussen, K. (2014). Influence of pallets on the behaviour and design of steel drive-in racks. Journal of Constructional Steel Research, 97 10-23. Guo, W. (2014). Elastic models for nonlinear response of rigid passive piles. International Journal for Numerical and Analytical Methods in Geomechanics, Online First Guo, W. Dong. (2014). Case studies on response of laterally loaded nonlinear piles. Geotechnical Engineering, 45 (2), 7077. Hadi, M. N. S. & Le, T. D. (2014). Behaviour of hollow core square reinforced concrete columns wrapped with CFRP with different fibre orientations. Construction and Building Materials, 50 (January), 62-73. Hadi, M. N. S. & Lei, X. (2014). Spline-shape modification for FRP-confined concrete columns: theory and evaluation. In R. El-Hacha (Eds.), 7th International Conference on FRP Composites in Civil Engineering (CICE 2014) (pp. 1-6). United States: International Institute for FRP in Construction. Hadi, M. N. S. & Tran, T. Minh. (2014). Retrofitting nonseismically detailed exterior beam-column joints using concrete covers together with CFRP jacket. Construction and Building Materials, 63 161-173.

Hai, F. Ibney., Yamamoto, K. & Lee, C. (2014). Introduction to membrane biological reactors. In F. Ibney. Hai, K. Yamamoto & C. Lee (Eds.), Membrane Biological Reactors: Theory, Modeling, Design, Management and Applications to Wastewater Reuse (pp. 1-27). United Kingdom: IWA Publishing. Han, Y., Yang, S., Dharmasiri, N. & Sivakumar, M. (2014). Effects of sample size and concentration of seeding in LDA measurements on the velocity bias in open channel flow. Flow Measurement and Instrumentation, 38 92-97. Heitor, A., Indraratna, B. & Rujikiatkamjorn, C. (2014). Aspects related to the small strain shear modulus behaviour of compacted soils subjected to wetting and drying. Geocongress Technical Papers: Geo-characterization and Modelling for Sustainability (pp. 1433-1442). United States: American Society of Civil Engineers. Heitor, A., Indraratna, B. & Rujikiatkamjorn, C. (2014). Role of the compaction energy level on the small strain stiffness of a silty sand soil subjected to wetting and drying. Unsaturated Soils: Research and Applications (UNSAT) (pp. 749-754). United Kingdom: CRC Press. Holloway, R. W., Regnery, J., Nghiem, L. D. & Cath, T. Y. (2014). Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor. Environmental Science and Technology (Washington), 48 (18), 10859-10868. Hossain, M. A., Ngo, H. H., Guo, W. S., Nghiem, L. D., Hai, F. I., Vigneswaran, S. & Nguyen, T. V. (2014). Competitive adsorption of metals on cabbage waste from multi-metal solutions. Bioresource Technology, 160 79-88. Hu, G., Xu, J., Ren, T., Dong, Y., Qin, W. & Shan, Z. (2014). Field investigation of using water injection through inseam gas drainage boreholes to control coal dust from the longwall face during the influence of abutment pressure. International Journal of Mining, Reclamation and Environment, Online First 1-16. Huang, M. & Zhong, R. (2014). Coupled horizontal-rocking vibration of partially embedded pile groups and its effect on resonance of offshore wind turbine structures. Yantu Gongcheng Xuebao, 36 (2), 286-294. Hungerford, F. & Ren, T. X. (2014). Directional drilling in unstable environments. International Journal of Mining Science and Technology, 24 (3), 397-402.

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Indraratna, B. N., Ni, J. & Rujikiatkamjorn, C. (2014). Investigation on effectiveness of a prefabricated vertical drain during cyclic loading. IOP Conference Series: Materials Science and Engineering, 10 (1), Indraratna, B., Kumara, C., Zhu , S. & Sloan, S. W. (2014). Mathematical modeling and experimental verification of fluid flow through deformable rough rock joints. International Journal of Geomechanics, Online First 04014065-104014065-11. Indraratna, B., Ngo, N. & Rujikiatkamjorn, C. (2014). Closure to Deformation of Coal Fouled Ballast Stabilized with Geogrid under Cyclic Load¿ by Buddhima Indraratna, Ngoc Trung Ngo, and Cholachat Rujikiatkamjorn. Journal of Geotechnical and Geoenvironmental Engineering, 140 (6), 1-1. Indraratna, B., Ngo, N., Rujikiatkamjorn, C. & Vinod, J. S. (2014). Behavior of fresh and fouled railway ballast subjected to direct shear testing: discrete element simulation. International Journal of Geomechanics, 14 (1), 34-44. Indraratna, B., Nimbalkar, S. & Neville, T. (2014). Performance assessment of reinforced ballasted rail track. Proceedings of the Institution of Civil Engineers: Ground Improvement, 167 (1), 24-34. Indraratna, B., Nimbalkar, S. & Rujikiatkamjorn, C. (2014). Enhancement of rail track performance through utilisation of geosynthetic inclusions. Geotechnical Engineering Journal, 45 (1), 17-27. Indraratna, B., Nimbalkar, S. & Rujikiatkamjorn, C. (2014). Modernisation of rail tracks for higher speeds and greater freight. Second International Conference on Railway Technology: Research, Development and Maintenance (Railways 2014) (pp. 1-20). Scotland: Civil-Comp Press.

Indraratna, B., Rujikiatkamjorn, C. & Balasubramaniam, A. S. (2014). Consolidation of estuarine marine clays for coastal reclamation using vacuum and surcharge loading. In M. Isklander, J. Garlanger & M. Hussein (Eds.), From Soil Behavior Fundamentals to Innovations in Geotechnical Engineering : honoring Roy E. Olson (pp. 358-369). United States: American Society of Civil Engineers. http://cedb.asce.org Indraratna, B., Rujikiatkamjorn, C. & Nimbalkar, S. (2014). Ground improvement for rail, port and road, infrastructure - from theory to practice. International Conference on Geotechnical Engineering (Geoshanghai 2014) (pp. 1-19). United States: American Society of Civil Engineers. Indraratna, B., Rujikiatkamjorn, C., Nguyen, V. & Raut, A. (2014). Analytical solutions for filtration process based on the constriction size concept. GEO-Congress 2014: GeoCharacterisation and Modeling for Sustainability (pp. 9991006). United States: American Society of Civil Engineers. Indraratna, B., Thirukumaran, S., Brown, E. T. & Zhu , S. (2014). Modelling the Shear Behaviour of Rock Joints with Asperity Damage Under Constant Normal Stiffness. Rock Mechanics and Rock Engineering, Online First Indraratna, B., Thirukumaran, S., Brown, E. T., Premadasa, W. & Gale, W. (2014). A technique for three-dimensional characterisation of asperity deformation on the surface of sheared rock joints. International Journal of Rock Mechanics and Mining Sciences, 70 483-495. Kaewunruen, S., Remennikov, A. M., Aikawa, A. & Sakai, H. (2014). Free vibrations of interspersed railway track systems in three-dimensional space. Acoustics Australia, 42 (1), 20-26. Kong, S., Cheng, Y., Ren, T. & Liu, H. (2014). A sequential approach to control gas for the extraction of multi-gassy coal seams from traditional gas well drainage to mining-induced stress relief. Applied Energy, 131 67-78. Li, X., Zhao, B., Wang, Z., Xie, M., Song, J., Nghiem, L. D., He, T., Yang, C., Li, C. & Chen, G. (2014). Water reclamation from shale gas drilling flow-back fluid using a novel forward osmosis¿vacuum membrane distillation hybrid system. Water Science and Technology, 69 (5), 1036-1044.

Indraratna, B., Nimbalkar, S., Coop, M. & Sloan, S. W. (2014). A constitutive model for coal-fouled ballast capturing the effects of particle degradation. Computers and Geotechnics, 61 (September), 96-107.

Liang, F., Song, Z. & Guo, W. (2014). Group interaction on vertically loaded piles in saturated poroelastic soil. Computers and Geotechnics, 56 1-10.

Indraratna, B., Pathirage, P., Rowe, K. & Banasiak, L. (2014). Coupled hydro-geochemical modelling of a permeable reactive barrier for treating acidic groundwater. Computers and Geotechnics, 55 (January), 429-439.

Liang, F., Song, Z. & Guo, W. (2014). Integral equation method for interaction effect of stress of vertically loaded pile groups considering consolidation. Yantu Gongcheng Xuebao, 36 (5), 847-854.

Indraratna, B., Premadasa, W., Brown, E. T., Gens, A. & Heitor, A. (2014). Shear strength of rock joints influenced by compacted infill. International Journal of Rock Mechanics and Mining Sciences, 70 296-307.

Lin, Z. & Dai, Z. (2014). Interaction coefficients method for calculating piles group settlements considering reinforcing and restraining effect. Yantu Lixue/Rock and Soil Mechanics, 35 (S1), 221-226.

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Hussaini, S. K. Karimullah., Indraratna, B. & Vinod, J. S. (2014). An experimental investigation on the deformation and degradation behaviour of geogrid-reinforced ballast. Second International Conference on Railway Technology: Research, Development and Maintenance (pp. 1-12). Scotland: CivilComp Press.

Lu, M., Wang, S., Sloan, S. W., Indraratna, B. & Xie, K. (2014). Nonlinear radial consolidation of vertical drains under a general time variable loading. International Journal for Numerical and Analytical Methods in Geomechanics, Online first 1-12. Luo, W. Hai., Yuan, J., Luo, Y. Ming., Li, G. Xue., Nghiem, L. D. & Price, W. E. (2014). Effects of mixing and covering with mature compost on gaseous emissions during composting. Chemosphere, 117 (December), 14-19. Luo, W., Hai, F. I., Price, W. E., Guo, W., Ngo, H. H., Yamamoto, K. & Nghiem, L. D. (2014). High retention membrane bioreactors: challenges and opportunities. Bioresource Technology, 167 539-546. Luo, Y., Guo, W., Ngo, H. H., Nghiem, L. D., Hai, F. I., Kang, J., Xia, S., Zhang, Z. & Price, W. E. (2014). Removal and fate of micropollutants in a sponge-based moving bed bioreactor. Bioresource Technology, 159 (May), 311-319.

Nemcik, J., Ma, S., Aziz, N., Ren, T. & Geng, X. (2014). Numerical modelling of failure propagation in fully grouted rock bolts subjected to tensile load. International Journal of Rock Mechanics and Mining Sciences, 71 293-300. Nemcik, J., Mirzaghorbanali, A. & Aziz, N. (2014). An elastoplastic constitutive model for rock joints under cyclic loading and constant normal stiffness conditions. Geotechnical and Geological Engineering, 32 (2), 321-335. Nghiem, L. D. & Espendiller, C. (2014). Effects of organic and colloidal fouling on the rejection of two pharmaceutically active compounds (PhACs) by nanofiltration processes: role of membrane foulants. Desalination and Water Treatment, 52 (4-6), 633-642. Nghiem, L. D., Manassa, P., Dawson, M. & Fitzgerald, S. K. (2014). Oxidation reduction potential as a parameter to regulate micro-oxygen injection into anaerobic digester for reducing hydrogen sulphide concentration in biogas. Bioresource Technology, 173 443-447.

RESEARCH

Luo, Y., Guo, W., Ngo, H. Hao., Nghiem, L. Duc., Hai, F. Ibney., Zhang, J. & Liang, S. (2014). A review on the occurrence of micropollutants in the aquatic environment and their fate and removal during wastewater treatment. Science of the Total Environment, 473-474 (March), 619-641.

Nghiem, L. D., Nguyen, T. T., Manassa, P., Fitzgerald, S. K., Dawson, M. & Vierboom, S. (2014). Co-digestion of sewage sludge and crude glycerol for on-demand biogas production. International Biodeterioration and Biodegradation, 95 160-166.

Ma, S., Nemcik, J. & Aziz, N. (2014). Simulation of fully grouted rockbolts in underground roadways using FLAC2D. Canadian Geotechnical Journal, 51 (8), 911-920.

Ngo, N., Indraratna, B. & Rujikiatkamjorn, C. (2014). DEM simulation of the behaviour of geogrid stabilised ballast fouled with coal. Computers and Geotechnics, 55 (January), 224-231.

Ma, S., Nemcik, J., Aziz, N. & Zhang, Z. (2014). Analytical model for rock bolts reaching free end slip. Construction and Building Materials, 57 30-37.

Nguyen, L., Hai, F. Ibney., Yang, S., Kang, J., Leusch, F., Roddick, F., Price, W. E. & Nghiem, L. D. (2014). Removal of pharmaceuticals, steroid hormones, phytoestrogens, UV-filters, industrial chemicals and pesticides by Trametes versicolor: role of biosorption and biodegradation. International Biodeterioration and Biodegration, 88 (March), 169-175.

Mirzaghorbanali, A., Nemcik, J. & Aziz, N. (2014). A study of the shear behaviour of infilled rock joints under cyclic loadng and constant normal stiffness conditions. 14th Coal Operators Conference (pp. 210-215). Australia: University of Wollongong. Mirzaghorbanali, A., Nemcik, J. & Aziz, N. (2014). Effects of cyclic loading on the shear behaviour of infilled rock joints under constant normal stiffness conditions. Rock Mechanics and Rock Engineering, 47 (4), 1373-1391. Mirzaghorbanali, A., Nemcik, J. & Aziz, N. (2014). Effects of shear rate on cyclic loading shear behaviour of rock joints under constant normal stiffness conditions. Rock Mechanics and Rock Engineering, 47 (5), 1931-1938. Mirzaghorbanali, A., Rasekh, H., Aziz, N. & Nemcik, J. (2014). Effects of shearing direction on shear behaviour of rock joints. 14th Coal Operators Conference (pp. 202-209). Australia: University of Wollongong. Modin, O., Hai, F. I., Nghiem, L. D., Basile, A. & Fukushi, K. (2014). Gas-diffusion, extractive, biocatalytic and electrochemical membrane biological reactors. In F. Ibney. Hai & C. Lee (Eds.), Membrane Biological Reactors: Theory, Modeling, Design, Management and Applications to Wastewater Reuse (pp. 299-333). United Kingdom: IWA Publishing.

Nguyen, N. Luong., Hai, F. I., Kang, J., Leusch, F., Roddick, F., Magram, S. Faraj., Price, W. E. & Nghiem, L. D. (2014). Enhancement of trace organic contaminant degradation by crude enzyme extract from Trametes versicolor culture: Effect of mediator type and concentration. Journal of the Taiwan Institute of Chemical Engineers, 45 (4), 1855-1862. Nguyen, N. Luong., Hai, F. I., Nghiem, L. D., Kang, J., Price, W. E., Park, C. & Yamamoto, K. (2014). Enhancement of removal of trace organic contaminants by powdered activated carbon dosing into membrane bioreactors. Journal of the Taiwan Institute of Chemical Engineers, 45 (2), 571-578. Nguyen, N. Luong., Hai, F. I., Price, W. E., Leusch, F. D. L., Roddick, F., Ngo, H. H., Guo, W., Magram, S. F. & Nghiem, L. D. (2014). The effects of mediator and granular activated carbon addition on degradation of trace organic contaminants by an enzymatic membrane reactor. Bioresource Technology, 167 169-177. Nguyen, N. Luong., Hai, F. I., Price, W. E., Leusch, F., Roddick, F., Mcadam, E. J., Magram, S. Faraj. & Nghiem, L. D. (2014). Continuous biotransformation of bisphenol A and diclofenac by laccase in an enzymatic membrane reactor. International Biodeterioration Biodegradation, In Press

76 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Patel, V. I., Liang, Q. & Hadi, M. N. S. (2014). Behavior of biaxially-loaded rectangular concrete-filled steeltubular slender beam-columns with preload effects. Thin Walled Structures, 79 (June), 166-177. Patel, V. Ishvarbhai., Liang, Q. & Hadi, M. N. S. (2014). Numerical analysis of high-strength concrete-filled steel tubular slender beam-columns under cyclic loading. Journal of Constructional Steel Research, 92 183-194. Patel, V. Ishvarbhai., Liang, Q. Quan. & Hadi, M. N. S. (2014). Biaxially loaded high-strength concrete-filled steel tubular slender beam-columns, part II: parametric study. Journal of Constructional Steel Research, In Press Patel, V., Liang, Q. & Hadi, M. N. S. (2014). Nonlinear analysis of axially loaded circular concrete-filled stainless steel tubular short columns. Journal of Constructional Steel Research, 101 (October), 9-18. Pham, T. M. & Hadi, M. N. S. (2014). Confinement model for FRP confined normal- and high-strength concrete circular columns. Construction and Building Materials, 69 83-90. Pham, T. M. & Hadi, M. N. S. (2014). Stress prediction model for FRP confined rectangular concrete columns with rounded corners. Journal of Composites for Construction, 18 (1), 04013019-1-04013019-10. Pham, T. Minh. & Hadi, M. N. S. (2014). Predicting stress and strain of FRP-confined square/retangular columns using artificial neural networks. Journal of Composites for Construction, Just released 04014019-1-04014019-9. Phan, H. V., Hai, F. I., Kang, J., Dam, H. K., Zhang, R., Price, W. E., Broeckmann, A. & Nghiem, L. D. (2014). Simultaneous nitrification/denitrification and trace organic contaminant (TrOC) removal by an anoxic¿aerobic membrane bioreactor (MBR). Bioresource Technology, 165 96-104. Porter, I., Shan, Z., Nemcik, J. & Baafi, E. (2014). Title Full scale tests to compare the strength of polymer liners with high tensile steel mesh. 14th Coal Operators’’ Conference (pp. 193-201). Australia: University of Wollongong. Qiao, Q. Q., Nemcik, J., Porter, I., Baafi, E., Zhang, Z. Y. & Shan, Z. J. (2014). Development of testing methods of thin spray-on liner shear-bond strength. In R. Alejano, A. Perucho, C. Olalla & R. Jimenez (Eds.), Proceedings of EUROROCK: Rock Engineering and Rock Mechanics: Structures in and on Rock Masses (pp. 125-130). United Kingdom: Taylor & Francis Group. Qin, H. & Guo, W. Dong. (2014). Limiting force profile and laterally loaded rigid piles in sand. Applied Mechanics and Materials, 553 452-457.

Ramezanianpour, M. & Sivakumar, M. (2014). An analytical flux decline model for membrane distillation. Desalination, 345 1-12. Rashid, M., Pham, S. Q. T., Sweetman, L. J., Alcock, L. J., Wise, A., Nghiem, L. D., Triani, G., in het Panhuis, M. & Ralph, S. F. (2014). Synthesis, properties, water and solute permeability of MWNT buckypapers. Journal of Membrane Science, 456 175-184. Remennikov, A. & Kaewunruen, S. (2014). Determination of prestressing force in railway concrete sleepers using dynamic relaxation technique. Journal of Performance of Constructed Facilities, Online First Remennikov, A. M. & Kaewunruen, S. (2014). Experimental load rating of aged railway concrete sleepers. Engineering Structures, 76 147-162. Remennikov, A. M. & Uy, B. (2014). Explosive testing and modelling of square tubular steel columns for near-field detonations. Journal of Constructional Steel Research, 101 290-303. Remennikov, A., Mutton, V., Nimbalkar, S. & Ren, T. (2014). Experimental and numerical investigation of high-yield grout ore pass plugs to resist impact loads. International Journal of Rock Mechanics and Mining Sciences, 70 1-15. Ren, T. & Wang, F. (2014). Gas reservoir simulation for enhanced gas recovery with nitrogen injection in low permeability coal seams. International Journal of Oil, Gas and Coal Technology, Ren, T. & Xu, J. (2014). Guest editorial-Special issue on Green Mining. International Journal of Mining Science and Technology, 24 (3), 291-292. Ren, T. (2014). Coal sorption characteristics and coal surface tension. International Journal of Oil, Gas and Coal Technology, Ren, T., Wang, Z. & Cooper, G. (2014). CFD modelling of ventilation and dust flow behaviour above an underground bin and the design of an innovative dust mitigation system. Tunnelling and Underground Space Technology, 41 (1), 241254. Rujikiatkamjorn, C. & Indraratna, B. (2014). Environmental sustainability of soft soil improvement via vacuum and surcharge preloading. GEO-Congress 2014: GeoCharacterisation and Modeling for Sustainability (pp. 36583665). United States: American Society of Civil Engineers. Sahis, M., Bhattacharya, G. & Chowdhury, R. N. (2014). Reliability analysis of rainfall induced slope instability of unsaturated soil slopes. Unsaturated Soils: Research and Applications - Proceedings of the 6th International Conference on Unsaturated Soils, UNSAT 2014 (pp. 1287-1293). Semblante, G., Hai, F. Ibney., Ngo, H. H., Guo, W., You, S., Price, W. E. & Nghiem, L. D. (2014). Sludge cycling between aerobic, anoxic and anaerobic regimes to reduce sludge production during wastewater treatment: Performance, mechanisms, and implications. Bioresource Technology, 155 (March), 395-409.

2013 – 2014 ANNUAL REPORT 77

RESEARCH

Nguyen, N. Luong., Hai, F. Ibney., Kang, J., Magram, S. Faraj., Price, W. E. & Nghiem, L. D. (2014). Impact of 1-hydroxybenzotriazole dosing on trace organic contaminant degradation by laccase. Journal of Water Sustainability, 4 (1), 41-48.

Shan, Z., Porter, I., Nemcik, J. & Baafi, E. (2014). Comparing the reinforcement capacity of welded steel mesh and a thin spray-on liner using large scale laboratory tests. International Journal of Mining Science and Technology, 24 (3), 373-377. Shan, Z., Porter, I., Nemcik, J. & Qiao, Q. (2014). Effect of different curing conditions on the compressive and flexural properties of Paris. 14th Coal Operators Conference (pp. 103108). Australia: University of Wollongong. Sharafi, P., Hadi, M. N. S. & Teh, L. H. (2014). Geometric design optimization for dynamic response problem of continuous reinforced concrete beams. Journal of Computing in Civil Engineering, 28 (2), 202-209. Sharafi, P., Teh, L. H. & Hadi, M. N. S. (2014). Conceptual design optimization of rectilinear building frames: a knapsack problem approach. Engineering Optimization, Online First 1-21. Sharafi, P., Teh, L. H. & Hadi, M. N. S. (2014). Shape optimization of thin-walled steel sections using graph theory and ACO algorithm. Journal of Constructional Steel Research, 101 331-341. Sheikh, M. Neaz. & Légeron, F. (2014). Performance based seismic assessment of bridges designed according to Canadian Highway Bridge Design Code. Canadian Journal of Civil Engineering, 41 (9), 777-787.

RESEARCH

Shon, H. Kyong., Nghiem, L. Duc., Kim, S., Chiemchaisri, C., Aravinthan, V., Virkutyte, J., Shu, L. & Jegatheesan, V. (2014). Special issue on the challenges in environmental science and engineering-CESE-2012 9¿13 September 2012, RACV City Club, Melbourne, Australia. Desalination and Water Treatment, 52 (4-6), 555-555. Simon, A. R., Fujioka, T., Price, W. & Nghiem, L. (2014). Sodium hydroxide production from sodium carbonate and bicarbonate solutions using membrane electrolysis: A feasibility study. Separation and Purification Technology, 127 (April), 70-76. Su, L., Lu, C., Deng, G., Tieu, A. Kiet., Zhang, L., Guagliardo, P., Samarin, S. & Williams, J. (2014). Vacancy-type defects study on ultra-fine grained aluminium processed by severe plastic deformation. Science of Advanced Materials, 6 (7), 1338-1345. Sun, Q. D., Indraratna, B. & Nimbalkar, S. (2014). Effect of cyclic loading frequency on the permanent deformation and degradation of railway ballast. Geotechnique: international journal of soil mechanics, Online First Sun, Y., Indraratna, B. & Nimbalkar, S. (2014). Threedimensional characterisation of particle size and shape for ballast. Geotechnique Letters, 4 (3), 197-202. Sun, Y., Xiao, Y. & Ju, W. (2014). Bounding surface model for ballast with additional attention on the evolution of particle size distribution. Science China Technological Sciences, 57 (7), 1352-1360.

Teh, L. H. & Gilbert, B. P. (2014). Net section tension capacity of equal angle braces bolted at different legs. Journal of Structural Engineering, 140 (6), 06014002-1-06014002-5. Teh, L. H. & Uz, M. (2014). Effect of loading direction on the bearng capacity of cold-reduced steel sheets. Journal of Structural Engineering, Online First 06014005-1-06014005-5. Teh, L. H. & Uz, M. (2014). Ultimate shear-out capacities of structural steel bolted connections. Journal of Structural Engineering, 04014152-1-04014152-9. Tennakoon, N. & Indraratna, B. (2014). Behaviour of clay-fouled ballast under cyclic loading. Geotechnique: international journal of soil mechanics, 64 (6), 502-506. Tennakoon, N., Indraratna, B. & Nimbalkar, S. (2014). Impact of ballast fouling on rail tracks. Second International Conference on Railway Technology: Research, Development and Maintenance (pp. 1-11). Scotland: Civil-Comp Press. Tran, T. M., Hadi, M. N. S. & Pham, T. M. (2014). A new empirical model for shear strength of reinforced concrete beam¿column connections. Magazine of Concrete Research, 66 (10), 514-530. Trani, L. D. & Indraratna, B. (2014). A procedure to assess subballast filtration under cyclic loading. Second International Conference on Railway Technology: Research, Development and Maintenance (pp. 1-11). Scotland: Civil-Comp Press. Tu, K. L., Chivas, A. R. & Nghiem, L. D. (2014). Effects of chemical preservation on flux and solute rejection by reverse osmosis membranes. Journal of Membrane Science, 472 202-209. Uz, M. & Hadi, M. N. S. (2014). Optimal design of semi active control for adjacent buildings connected by mr damper based on integrated fuzzy logic and multi-objective genetic algorithm. Engineering Structures, 69 (June), 135-148. Venticinque, G. & Nemcik, J. (2014). New fracture model for the progressive failure of rock slopes. 2014 Coal Operators’’ Conference (pp. 82-88). Australia: University of Wollongong. Venticinque, G., Nemcik, J. A. & Ren, T. X. (2014). A new fracture model for the prediction of longwall caving characteristics. International Journal of Mining Science and Technology, 24 (3), 369-372. Vinod, J., Hyodo, M., Indraratna, B. & Kajiyama, S. (2014). Shear behaviour of methane hydrate bearing sand: DEM simulations. In K. Soga, K. Kumar & G. Biscontin (Eds.), 2014 IS Geomechanics from Micro to Macro (IS-Cambridge 2014) (pp. 355-359). United Kingdom: CRC Press - Taylor and Francis. Wang, G. F., Ren, T. X. & Cook, C. (2014). Goaf frictional ignition and its control measures in underground coal mines. In X. He, H. Mitri, B. Nie, Y. Wang, T. X. Ren, W. Chen & X. Li (Eds.), Progress in Mine Safety Science and Engineering II: Proceedings of the 2nd International Symposium of Mine Safety Science and Engineering (pp. 451-459). United Kingdom: Taylor & Francis Group.

78 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Wang, G., Ren, T., Wang, K. & Zhou, A. (2014). Improved apparent permeability models of gas flow in coal with Klinkenberg effect. Fuel: the science and technology of fuel and energy, 128 53-61.

Yang, J., Wang, S., Zhang, H. & Cao, C. (2014). Particle-scale analysis of key technologies on cut-and-over tunnel in slope engineering. Journal of Engineering Science and Technology Review, 7 (4), 46-52.

Wang, G., Wang, K. & Ren, T. X. (2014). Improved analytic methods for coal surface area and pore size distribution determination using 77 K nitrogen adsorption experiment. International Journal of Mining Science and Technology, 24 (3), 329-334.

Yang, S. & Ding, D. (2014). Drag-reducing flows in laminarturbulent transition region. Journal of Fluids Engineering, Transactions of the ASME, 136 (10), 1-9.

Wang, W., Sheikh, M. Neaz., Hadi, M. N. S. & Lyons, B. (2014). Behaviour of GFRP tube reinforced concrete columns under axial compression. 7th International Conference on FRP Composites in Civil Engineering (CICE 2014) (pp. 1-6). United States: International Institute for FRP in Construction. Wang, X., Zhang, D., Li, G., Ren, T. Xiang. & Zhang, W. (2014). Methane drainage and utilization technologies for high gassy and low permeability coal seams in tiefa mining area. Electronic Journal of Geotechnical Engineering, 19 (A), 101115.

Ying, K. Sih., Remennikov, A. M. & Uy, B. (2014). Numerical investigation of the response of protective barrier under blast loading. Applied Mechanics and Materials, 567 440-445. Yousuf, M., Uy, B., Tao, Z., Remennikov, A. & Liew, J. Richard. (2014). Impact behaviour of pre-compressed hollow and concrete filled mild and stainless steel columns. Journal of Constructional Steel Research, 96 54-68. Yu, T. & Remennikov, A. (2014). Novel hybrid FRP tubular columns for sustainable mining infrastructure: Recent research at University of Wollongong. International Journal of Mining Science and Technology, 24 (3), 311-316.

Wijekoon, K. C., Hai, F. I., Kang, J., Price, W. E., Guo, W., Ngo, H. H., Cath, T. Y. & Nghiem, L. D. (2014). A novel membrane distillation-thermophilic bioreactor system: biological stability and trace organic compound removal. Bioresource Technology, 159 (May), 334-341.

Yu, T., Hu, Y. M. & Teng, J. G. (2014). FRP-confined circular concrete-filled steel tubular columns under cyclic axial compression. Journal of Constructional Steel Research, 94 33-48.

Wijekoon, K., Hai, F. Ibney., Kang, J., Price, W. E., Cath, T. & Nghiem, L. D. (2014). Rejection and fate of trace organic compounds (TrOCs) during membrane distillation. Journal of Membrane Science, 453 (March), 636-642.

Zhang, L., Ren, T. X. & Aziz, N. I. (2014). Influences of temperature and moisture on coal sorption characteristics of a bituminous coal from the Sydney Basin, Australia. International Journal of Oil, Gas and Coal Technology, 8 (1), 62-78.

Xie, M., Nghiem, L. D., Price, W. E. & Elimelech, M. (2014). Impact of organic and colloidal fouling on trace organic contaminant rejection by forward osmosis: role of initial permeate flux. Desalination, 336 (March), 146-152.

Zhang, S. S., Teng, J. G. & Yu, T. (2014). Bond strength model for CFRP strips near-surface mounted to concrete. Journal of Composites for Construction, 18 (3), A40140031-A4014003-12.

Xie, M., Nghiem, L. D., Price, W. E. & Elimelech, M. (2014). Relating rejection of trace organic contaminants to membrane properties in forward osmosis: measurements, modelling and implications. Water Research, 49 (February), 265-274.

Zhang, Z., Nemcik, J., Qiao, Q. & Geng, X. (2014). A model for water flow through rock fractures based on friction factor. Rock Mechanics and Rock Engineering, Online First 1-13.

Xie, M., Nghiem, L. D., Price, W. E. & Elimelech, M. (2014). Toward resource recovery from wastewater: phosphorus extraction from digested sludge using hybrid forward osmosis - membrane distillation process. Environmental Science & Technology Letters, 1 (2), 191-195. Xu, C., Cheng, Y., Ren, T., Wang, L., Kong, S. & Lu, S. (2014). Gas ejection accident analysis in bed splitting under igneous sills and the associated control technologies: A case study in the Yangliu Mine, Huaibei Coalfield, China. Natural Hazards, 71 (1), 109-134. Yaghmaei-Sabegh, S., Shoghian, Z. & Sheikh, M. Neaz. (2014). A new model for the prediction of earthquake groundmotion duration in Iran. Natural Hazards, 70 (1), 69-92.

Zhang, Z., Nemcik, J., Ren, T. X. & Zhang, J. (2014). Influence of void space on microscopic behavior of fluid flow in rock joints. International Journal of Mining Science and Technology, 24 (3), 335-340. Zhong, R. & Huang, M. (2014). Centrifuge tests for seismic response of caisson-pile composite foundation. Yantu Lixue, 35 (2), 380-388. Zhuang, Z., Horpibulsuk, S. & Liu, M. D. (2014). A study on the compression curves of reconstituted clays with water contents. 8th European Conference on Numerical Methods in Geotechnical Engineering - Proceedings of the 8th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE) (pp. 221-225). The Netherlands: CRC Press/Balkema.

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 79

RESEARCH

Wang, K., Wang, G., Ren, T. & Cheng, Y. (2014). Methane and CO2 sorption hysteresis on coal: a critical review. International Journal of Coal Geology, 132 60-80.

Yang, S., Han, Y., Lin, P., Jiang, C. & Walker, R. (2014). Experimental study on the validity of flow region division. Journal of Hydro-Environment Research,

Selected Awards and Achievements

paper and the oral presentation. The International Congress on Environmental Geotechnics is held every 4 years and is the largest conference in the field of Geo-environmental engineering and related disciplines. Buddhima Indraratna received the Vice-Chancellor’s Award for Research Partnership, University of Wollongong, Australia, 2013. Cholachat Rujikiatkamjorn has been announced as the Winner of Young Member Award of the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE). The award is given every 4 years during the ISSMGE Conference and attracts strong entrants internationally. Cholachat was nominated by AGS for this ISSMGE Young Member award, which is based on academic achievements and outstanding contributions to the field of geotechnical engineering by a young member less than 36 years of age.

RESEARCH

Buddhima Indraratna from the Centre for Geomechanics and Railway Engineering at the University of Wollongong and a Program Leader of the ARC Centre of Excellence in Geotechnical Science and Engineering, won the Chandra S Desai Medal awarded by the International Association for Computer Methods and Advances in Geomechanics (IACMAG) at its 14th conference, held in Kyoto, Japan, 2014. Buddhima received his award from Professor Desai, Regents’ Professor of Civil Engineering at the University of Arizona. Professor Desi is regarded as the early pioneer of the modern day analytical and numerical methods in geomechanics and the inventor of the Disturbed State Concept applied to yielding materials and interfaces. Ernest Baafi received 2014 Australasian Institute of Mining and Metallurgy (AusIMM) Institute Service Award in recognition of his long and meritorious service to the Institute. Faisal I. Hai served as the lead editor of a Membrane Bioreactor (MBR) book (ISBN: 9781780400655) published from International Water Association (IWA) publishing, UK (2014). Co-editors of the book include Prof Yamamoto (the inventor of MBR) and Prof Lee (Former Chair, IWA Membrane Technology Specialist Group). He is an Associate Editor of the reputed journal Water Science and Technology. Firman Siahaan was awarded best paper award in the Ground Improvement category, at the Soft Soils Conference held in Bandung, Indonesia, 2014. Ray Tolhurst received a National Office for Learning and Teaching (OLT) Citation for Outstanding Contributions to Student Learning for 2014, one of only three engineering citations throughout all Australian universities. Citations are awarded to those who have made a significant contribution to the quality of student learning in a specific area of responsibility over a sustained period. Ray received the citation for expertise and stewardship, linking mining and materials engineering educators with industry and professional groups, to produce an enriched program and outstanding graduate employability. Udeshini Pathirage, Buddhima Indraratna and Laura Banasiak received best paper award for their paper titled “A Novel Hydro-geochemical Model for Treating Acidic Groundwater Utilising a Permeable Reactive Barrier” at the 7th International Congress on Environmental Geotechnics, held in Melbourne, November 2014. The award was made by a judging panel on the basis of the quality of the written

Ngoc Trung supervised by Buddhima and Cholachat in the area of geosynthetically stabilised rail tracks has won a 2013 RTSA award for outstanding contribution to Australian Railways through PhD research. Timothy McCarthy led the construction team of students that designed and constructed Team UOW’s entry in Solar Decathlon China 2013. The house, named The Illawarra Flame was pre-fabricated in Wollongong before being shipped to Datong China where the students rebuilt it in less than 10 days. Team UOW defeated 20 other teams from around the world to take first prize in the competition. Timothy McCarthy received the Rotary International Pride in Workmanship Award 2013. This award was in recognition of the quality of workmanship executed in The Illawarra Flame house and in recognition of the win in China. Timothy McCarthy received the Green Gown International Award for Student Initiatives 2013. This UK award was for integrating sustainability in the curriculum through the Solar Decathlon project. Timothy McCarthy received the Lord Mayor’s Special Australia Day 2014 award for community engagement; in recognition of the high profile achieved for Wollongong through the Solar Decathlon project and for engagement with local industry and the public. Timothy McCarthy as part of Team UOW was awarded the Engineers Australia Sydney Division President’s Excellence Award 2014 as the outstanding Engineering Sustainability Project in the Sydney Region for 2013-2014. The Illawarra Flame house also received a Highly Commended certificate in the Sydney Division Environment and Heritage Excellence Award

80 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

•• High Pressure Tri-axial Apparatus

The School of Civil, Mining and Environmental is supported by well-equipped laboratories and workshops and a highly skilled team of support staff.

•• Arching and flow rate indicizers

The use of resources by external collaborators from industry is encouraged and enquiries are invited.

Special or unique equipment include: CIVIL

•• Large-scale direct shear tester with variable shear rate and displacement •• Particle and bulk material characterisation, including laser diffraction particle size analyser

ENVIRONMENTAL •• Pilot scale equipment •• One pilot scale reverse osmosis rig •• One pilot scale membrane distillation rig

•• large scale cylindrical tri-axial apparatus with dynamic actuator (300 mm in diameter)

•• One pilot scale screw conveyor rig for biosolids handling research

•• large scale cyclic prismoidal tri-axial rig with unrestrained sides (600x600x800 mm)

•• Two parallel pilot scale anaerobic digesters

•• large scale consolidatometer (650 mm in diameter for soft soil testing)

•• Specialised experimental systems

•• GDS controlled tri-axial apparatus •• cyclic filtration apparatus (240 mm in diameter) •• 500kN instron universal testing machine •• Large capacity drop hammer machines - unique •• 3M EVM series portable air quality logging systems (incl. Particulates, VOC, COx , NOx) •• Cyclic simple shear apparatus •• Unsaturated tri-axial apparatus •• Static/cyclic tri-axial apparatus •• Back pressure shear box apparatus •• GDS cyclic process simulation apparatus •• Ring shear apparatus

•• One pilot scale membrane bioreactor •• Four lab scale reverse osmosis systems •• Two membrane distillation systems •• Two forward osmosis systems •• Three membrane bioreactor systems •• Three parallel anaerobic digesters (28 L each) •• Sequencing batch reactor coupled with sludge digestion •• One UV radiation system •• One ozonation system •• Two lab scale ion exchange columns •• Major analytical instruments •• Agilent ICP-OES 710 •• Shimadzu TOC/TN analyser

2013 – 2014 ANNUAL REPORT 81

RESEARCH

Equipment and Facilities

•• Shimadzu GC-MS •• Shimadzu LC-MS •• Shimadzu HPLC •• Shimadzu IC •• Rame Hart Goniometer •• JOEL 6000 Bench top SEM •• Anton Paar Zeta Potential Analyser •• Biogas meter 5000

MINING •• Rock bolting single and double shear testing apparatus •• Overhead drill rig for short encapsulation pull testing of bolts and cable bolts •• Rock core drilling equipment •• Rock core end cutting machine •• Rock core end lapping machines •• Schmidt hammer •• compression testing machines (10, 50, 500, 900 and 5000 kN capacity •• Hoek Triaxial cells for 20, 30, 42 and 54 mm diameter testing •• Rock bolting load cells, 30 t, 60, •• t and 100 t capacity •• Cable bolt tensioner

RESEARCH

•• Rock drill •• circular saw for rock cutting •• core end lapping machine •• 30, 60 and 100 load cells for cable bolt tension monitoring •• personal dust samples for mine environment control (7 units) •• Hund hand-held dust sampler •• adsorption and desorption equipment for mine gas research •• Gas Chromatograph •• Multi-function Outburst Research Rig for mine gas research •• fast and slow gas desorption apparatus •• hand held gas monitoring equipment •• Precision balance for measuring dust and gas mass down to one micron •• micron

82 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

RESEARCH GRANTS GRANT INCOME 2013-2014 Agency Ref. No.

Year

Title

All Internal Researchers

Total Agency Awarded

Industry

CRC

Track Performance assessment capturing ballast degradation at high train speeds

Buddhima Indraratna, Cholachat Rujikiatkamjorn, Sanjay Nimbalkar

$360,000

Rhomberg Rail and Getzer

2014

DE140101349

Fibre Reinforced Polymer (FRP)-Confined Concrete-Encased Steel Composite Columns

Tao Yu(DECRA)

$390,749

2014

DP140103864

Novel high retention membrane bioreactors for sustainable water reuse: Process performance and optimization

Long Nghiem(Chief Investigator), Faisal Hai(Chief Investigator), William Price(Chief Investigator)

$284,109

2014

LE140100010

National Facility for Cyclic Testing of High-speed Rail (FCTHSR)

Buddhima Indraratna (Chief Investigator), Cholachat Rujikiatkamjorn (Chief Investigator), A Tieu (Chief Investigator), Alexander Remennikov (Chief Investigator), Sanjay Nimbalkar (Chief Investigator)

$1,700,000

2014

LP140100065

Performance of Soft Clay Consolidated by Biodegradable and Geosynthetic Vertical Drains under Vacuum Pressure for Transport Infrastructure

Buddhima Indraratna (Chief Investigator), Cholachat Rujikiatkamjorn (Chief Investigator)

$735,000

2014

Australian Coal Industry

Polymer based alternative to steel mesh for coal mine strat reinforcement and confinement

Ernest Baafi (Chief Investigator), Ian Porter (Chief Investigator)

Approximately $1000,000

2014

Research Grants Council of Hong Kong

FRP Tube-Confined Concrete Columns containing Recycled Concrete Lamps

Tao Yu in collaboration with Hong Kong Polytechnic University

HK836,450

2013

DP130102217

Evaluation of densification and degradation of ballast under cyclic train loading

Buddhima Indraratna(Chief Investigator), Cholachat Rujikiatkamjorn(Chief Investigator)

$342,000

2013

Research Grants Council of Hong Kong

Strengthening of Rectangular RC Columns through Shape Modification and FRP Confinement

Tao Yu in collaboration with Hong Kong Polytechnic University

HK$905,425

2013

LP130100839

Load-displacement and consolidation behaviour of soft soils stabilized by stone columns for transport infrastructure

Buddhima Indraratna(Chief Investigator), Cholachat Rujikiatkamjorn(Chief Investigator), Wei-Dong Guo(Chief Investigator)

$305,000

2013

ID13-2899

Integrating Indigenous student support through Indigenous perspectives embedded in engineering curricula

Thomas Goldfinch (Chief Investigator), Jade Kennedy (Chief Investigator), Elizabeth Leigh (Chief Investigator), Timothy McCarthy (Chief Investigator), Christopher Cook (Chief Investigator), Paul Chandler(Chief Investigator)

$212,000

2013

IH130100017

The Australian Steel Manufacturing Research Hub

Lip Teh(Chief Investigator)

$585,990

2013

LE130100028

Mobile soft soil in-situ testing laboratory

Buddhima Indraratna(Chief Investigator), Cholachat Rujikiatkamjorn(Chief Investigator)

$50,000

2013

China Shenhua Energy Group

Technologies for the prevention of spontaneous heating fires in large longwall goafs

Ting Ren

$250,000

China Coal Research Institute

2013

UIC International Links Grant Scheme

Applied technologies for green and safe mining of coal resources

Jan Nemcik & Ting Ren

$8,000

China University of Mining and Technology (CUMT) and China Coal Research Institute (CCRI)

2013

URC Research Partnerships Scheme

Applications of Steel Plates in Hybrid FRPSteel-Concrete Columns

Lip Teh, Tao Yu & Muhammad Hadi

$12,000

Bluescope Steel

2013

UIC International Links Grant Scheme

Research collaboration in hot-rolled and cold-formed steel structures

Lip Teh & Tim McCarthy

$10,950

IIT Madras

RESEARCH

2014

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 83

COMMUNICATION COMMUNICATION 84 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Alumni Once a student completes their degree at UOW, they become part of a global community of 120,000 alumni, a network of graduates across the world with the shared experience of studying at UOW. Below are members of our Alumni that have become very successful in their chosen career.

GEOFFREY MCINTOSH Geoffrey McIntosh BE (Hons), ME (Hons), FIEAust, CPEngGeoff McIntosh is a Chartered Professional Engineer and a Fellow of The Institution of Engineers Australia. As a cadet engineer with the Electricity Commission of NSW, Geoff graduated from the University of Wollongong (UOW) with an undergraduate honours degree in civil engineering in 1980 and a post-graduate Master’s degree in civil engineering in 1998. Between 1980 and 1988, he spent most of his time in the geotechnical investigations section of Elcom working primarily on the design of civil and earth structures for Eraring, Bayswater and Mt Piper Power Stations. In 1988, Geoff joined DJ Douglas and Partners (now Douglas Partners), a geotechnical and environmental engineering consultancy with about 100 staff. Initially as a Senior Geotechnical Engineer, Geoff worked in various offices of Douglas Partners on a range of projects and is now one of the Company’s Principal’s. Geoff has been a Director since 2004 and Chairman since 2010, with Douglas Partners now having 400 staff.

COMMUNICATION

Geoff has been the author and co-author of conference papers on the use of coal refuse in construction, dynamic compaction and building on landfills, vertical drains and treatment of acid sulphate soils. Geoff maintains an active interest in research with UOW.

PROFESSOR RANJITH PATHEGAMA Professor Ranjith Pathegama graduated with first class honours from University of Moratuwa Sri Lanka, and pursued Doctoral degree at the University of Wollongong under the guidance of Prof Indraratna. He was appointed as a lecturer in Monash’s Department of Civil Engineering in 2003, and within 10years he was promoted to a Full Professor. He was awarded an inaugural ARC Future Fellowship award in 2009, for research to alleviate the problem of greenhouse gas emissions through carbon sequestration in deep underground reservoirs. Prof Ranjith has supervised to completion 16 PhD and 3 Masters students, and was awarded our Vice-Chancellor’s Award for Excellence in Postgraduate Supervision – and a Vice-Chancellor’s Award for Excellence in Research in 2012. He has more than 225 refereed publications in reputed journal and conference proceedings, and his areas of research interests are in Geomechanics aspects of Energy and resource recoveries. Professor Ranjith has been elected a Fellow of Engineers Australia and the American Society of Civil Engineers.

2013 – 2014 ANNUAL REPORT 85

Plenary, Keynote and Invited Lectures Alex Remennikov was invited to deliver the Keynote Lecture at the CIES Symposium on National Road and Rail Infrastructure – Structural Engineering Prospective for Sustainable and Resilient Infrastructure at UNSW, Sydney in November 2014 entitled “Assessment of remaining life of railway prestressed concrete sleepers” Alex Remennikov delivered the invited presentation at the 2014 Explosives Forum in Canberra entitled “Explosive demolition of structures - proposal for an engineering course” Buddhima Indraratna was invited to present a Distinguished Presidential Lecture on Recent Advances in Soft Ground Improvement – From Bumpy Rides to Rapid Transit at the South East Asia Conference on Soft Soil Engineering and Ground Improvement, 2014, Bandung, Indonesia Buddhima Indraratna was invited to present a Keynote Lecture on Ground improvement in transport geotechnics from theory to practice at the 14th International Conference of International Association for Computer Methods and Advances in Computational Mechanics (IACMAG 2014), Kyoto Japan. Buddhima Indraratna was invited to present a Keynote Lecture on Ground Improvement for Rail, Port and Road, Infrastructure - From Theory to Practice at GeoShanghai, 2014, Shanghai, China. Buddhima Indraratna was invited to present a Keynote Lecture on Modernisation of Rail Tracks for Higher Speeds and Greater Freight”, at the Second International Conference on Railway Technology: Research, Development and Maintenance Railway 2014, Norway.

Martin Liu was invited to present a Keynote Lecture at International Conference on Advances in Civil Engineering for Sustainable Development, 2014, Nakhon Ratchasima, Thailand. Alex Remennikov was invited to present a Keynote Lecture at the 10th International Conference on Shock and Impact Loads on Structures, Singapore in November 2013 entitled “Impact and blast loading of steel and concrete filled steel members” (co-authored with Prof Brian Uy) Alex Remennikov was invited to present a Keynote Lecture at the 4th International Conference on Structural Engineering and Construction Management, Sri Lanka in December 2013 entitled “Utilising the benefits of infill materials in designing protective structures for security-sensitive environments”. Buddhima Indraratna was invited to present a Keynote Lecture on Rail Track Infrastructure for Enhanced Speed Analysis, Design and Construction Challenges at the Indian Geotechnical Conference (IGC 2013), India. Buddhima Indraratna was invited to present a General Report on Ground improvement/Grouting/Dredging at the 18th International Conference on Soil Mechanics and Geotechnical Engineering, 2013, Paris, France. Vinod Jayan Sylaja was invited to present a special lecture at the 7th International Conference on Case Histories in Geotechnical Engineering, 2013, Chicago, USA, on the paper entitled ‘DEM modelling of granular materials during cyclic loading’.

Buddhima Indraratna was invited to present a Keynote Lecture on theory to practice in Rail Geotechnology at the 9th International Conference on the Bearing Capacity of Roads, Railways and Airfields, 2014, Trodheim, Norway. Buddhima Indraratna was invited to present a Keynote Lecture on Consolidation of clay under vacuum combined surcharged loads at the first International Conference on Foundation and Soft Ground Engineering Challenges in Mekong Delta, 2014, Binh Duong, Vietnam.

COMMUNICATION

Buddhima Indraratna was invited to present a Keynote Lecture on Performance Appraisal of Ballasted Rail Track Stabilised by Geosynthetic Reinforcement and Shock Mats at the Seventh International Conference on Case Histories in Geotechnical Engineering, 2014, Chicago, USA. Cholachat Rujikiatkamjorn was invited to present an invited Lecture on Characterization of smear zone due to installation of vertical drains at the first International Conference on Foundation and Soft Ground Engineering Challenges in Mekong Delta, 2014, Binh Duong, Vietnam. Cholachat Rujikiatkamjorn was invited to present an Invited Lecture on Smear zone characterisation caused by vertical drain installation at the South East Asia Conference on Soft Soil Engineering and Ground Improvement, 2014, Bandung, Indonesia. Faisal I. Hai was invited to deliver two key note speeches at the International Conference on Next Generation Membrane Bioreactors held in Turkey in September, 2014 and Korea, February, 2013.

86 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

Visitors and Collaboration Wei Dong Guo was invited to collaborate with Hohai University 2014 (one of top three geotechnical groups in China) by Dean Professor Gao Yufen, and with Tsinghua University on research related to passive piles subjected to lateral spreading (Hohai) and physical modelling (Tsinghua). Masayuki Hyodo from the Department of Civil and Environmental Engineering, Yamaguchi University visited in March 2014 and presented a research seminar entitled “Slope failures in residential land on valley fills during 2011 Great East Japan Earthquake”. Yujin Lim from the Department of Civil, Environmental and Railroad Engineering, South Korea presented a seminar August 2014 on New Design Framework for Trackbed Foundation in Korea.

Guang-Ming Chen from Guangdong University of Technology visited UOW and gave a seminar titled “FE Modeling on Debonding Failures of FRP-Strengthened RC Beams Using Crack Band Model” on 9 December 2013. Tao Yu co-supervised Bing Zhang, a PhD student from The Hong Kong Polytechnic University who visited UOW during the period of 5 April 2013 to 5 July 2013. Wei Dong Guo was invited in 2013 and acted as a cosupervisor of a Tongji (China) PhD student conducting research in settlement prediction of pile groups in poroelastic soil. Tao Yu is the co-supervisor of Guan Lin, a PhD student from The Hong Kong Polytechnic University who visited UOW from December 2013 to March 2014, and from May 2014 to Aug 2014.”

Abraham Chung-Fai Chiu from the Geotechnical Research Institute at Hohai University, China visited in July 2014 and discussed collaborative research on modelling structured soil behaviour with Dr Martin Liu. Yeong-Bin Yang from the Department of Civil Engineering, National Taiwan University presented a well-attended seminar in February 2014, entitled “2.5D Finite Element Approach for Simulation of Train-Induced Ground Vibrations”, a highly efficient technique developed at NTU. Ronald Ziemian from the Department of Civil and Environmental Engineering, Bucknell University, Lewisburg, USA; a recipient of 2013 ASCE Shortridge Hardesty Award presented a most engaging seminar in March 2014 on the ethical dilemma faced by William LeMessurier, the chief structural engineer of Citicorp Center in New York City. Kerry Rowe from the Department of Civil Engineering, Queens University, Canada visited in November 2014 and presented a seminar on Transport Embankment Stability. Ben Young from the Department of Civil Engineering Graduate School, University of Hong Kong presented a unique seminar to the faculty in December 2014 on effective teaching techniques for undergraduate students.

COMMUNICATION

Shiguo Xiao from Southwest Jiaotong University, China visited UOW in October – December 2014 as a visiting senior fellow conducting research with Wei Dong Guo on slope stabilising piles for hillside development. Tao He from Shanghai Advanced Research Institute, China visited in February 2013 and presented a seminar on development of high performance membranes and processes for extreme conditions. Robert Driver from the Department of Civil and Environmental, University of Alberta, Canada, spent part of his study leave with Dr. Lip Teh in Spring 2013 and presented a seminar on steel plate shear walls; a very successful concept pioneered at Alberta that has found increasing applications around the world. Zihang-Dai from Fuzhou University is a visiting senior fellow at UOW working with Wei Dong Guo on research related to ground improvement using bambo, sand compaction piles, etc. from June 2013 – December 2015. Pengfei Fang from Zhejiang University visited UOW in August 2013 for discussions with Wei Dong Guo on collaborative research in the study of the behaviour of soft clay and structure interaction, and response of cyclically loaded piles.

2013 – 2014 ANNUAL REPORT 87

SEMINARS DATE

PRESENTER

TITLE

13-Feb-2014

Yeong-Bin Yang,

2.5D Finite/Infinite Element Approach for Simulation of Train-Induced Ground Vibrations

National Taiwan University, Taiwan 13-Mar

Ronald D. Zeimian

“Mr. Wriston, your building is not well………”

Bucknell University, Lewisburg, United States 25-Mar

Masayuki Hyodo Yamaguchi University, Japan

28-Mar

Sudip Basak,

Slope failures in residential land on valley fills during 2011 Great East Japan Earthquake Stone Column Reinforced Soft Ground Supporting Transport Infrastructure

University of Wollongong 23-Apr

Qingshen Chen, University of Wollongong

A Theoretical and Experimental Study on the Behaviour of LS-Treated Sandy Silt

22-May

Trung Thanh Nguyen, University of Wollongong

A Special Review of Natural Prefabricated Vertical Drains in Geo-engineering

23-May

Firman Siahaan,

3MT - Micromechanically inspired stone column behaviour

University of Wollongong 30-May

Mark Nelson,

Modelling Sludge Disintegration

University of Wollongong 30-Jun

Ana Heitor, University of Wollongong

1-Jul

Buddhima Indraratna, University of Wollongong

7-Jul

Abraham C. F Chiu, Hohai University, China

17-Jul

Nathan Narendrananthan,

Aspects related to the wetting and drying of unsaturated soils with special reference to small strain The role of vegetation and associated root suction and reinforcement on the stabilisation of transport corridors and sloping ground”. Effect of microstructures on water retention and permeability of cement treated soils Innovations on ground and pavement engineering

University of Wollongong 12-Aug

Yujin Lim,

New Design Framework for Trackbed Foundation in Korea

COMMUNICATION

Paichai University, China 1-Oct

Don Cameron, University of South Australia

1-Nov

Stacey Jane Vorwerk, University of South Australia

19-Nov

Kerry Rowe,

Salisbury initiative to monitor weather changes and the effect of weather to root water uptake Group work to identify the research gaps and get feedback from the audience for the data she has obtained so far Transport Embankment Stability

Queens University, Canada 19-Nov

Ted Brown, Golder Associates

19-Nov

Buddhima Indraratna,

Rock engineering development in tunnelling for transport and energy infrastructure Recent Technological Advances in Rail tracks

University of Wollongong 19-Nov

Scott Sloan,

The strength reduction method in geotechnical stability analysis

University of Newcastle 19-Nov

Mark Cassidy,

Contributions to improving the safety of offshore oil and gas platforms

University of Western Australia

88 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

19-Nov

Nasser Khalili, University of New South Wales

19-Nov

Richard Kelly,

Coupled flow-deformation analysis of unsaturated soils including hydraulic and mechanical hysteresis effects Future direction in laboratory and in-situ testing of soft soils

Coffey Geotechnics 19-Nov

Jeff H Si, SMEC International

19-Nov

Kim Chan, GHD

19-Nov

Peter Meers, Roads and Maritime Services, Wollongong

19-Dec

22-Jan-2013

Managing Mine Subsidence on the Hume Highway: Pavement and geotechnical interaction Excellence in Teaching = f(x)

The University of Hong Kong

What is f(x)?

Masayuki Hyodo,

Research and Development for Methane Hydrate Production in Deep Seabed and Permafrost

Tao He, Shanghai Advanced Research Institute, China

22-Feb

Design and Back-analysis of Tunnel Roof Support Systems for the Epping to Chatswood Rail Link

Ben Young

Yamaguchi University, Japan 21 -Feb

Optimisation of soft ground treatment using a two-stage reinforced soil wall system

Buddhima Indraratna,

Development of high performance membranes and processes for extreme conditions SMART tool workshop

Nayoma Tennakoon, Sanjay Nimbalkar, University of Wollongong Qingsheng Chen, University of Wollongong 26-Jun

Robert Driver,

Proposed ideas for constitutive model and current progress with respect to the proposed project schedule Steel Plate Shear Walls: Idea to Implementation

University of Alberta, Canada 22-Jul

Gabriele Chiaro, Ana Heitor,

Geotechnical Properties and Compaction Characteristics of Granular Wastes as Potential Port Reclamation Fill

Chazath Kaliboullah, Seyed Tasilloti 18-Oct

Qingsheng Chen,

Constitutive modelling for Subgrade Soil treated by Lignosulfonate

University of Wollongong

2013 â&#x20AC;&#x201C; 2014 ANNUAL REPORT 89

COMMUNICATION

20-Mar

Conferences and Workshops CONFERENCES The Coal Operatorsâ&#x20AC;&#x2122; Conference February 2013 and 2014 The Coal Operatorsâ&#x20AC;&#x2122; Conference is an annual event, held regularly at the University of Wollongong campus on February. The Conference is organised jointly between the University of Wollongong, the Illawarra Branch of The Australasian Institute of Mining and Metallurgy, and Mine Managers Association of Australia. The Conference address issues related to various aspects of modern coal mining operations, both surface and underground. The 6th International Symposium on Green Mining November 2013 The 6th International Symposium on Green Mining (ISGM), initiated by China University of Mining and Technology (CUMT) through its State Key Laboratory of Coal Resources and Safe Mining, was hosted by the School of Civil, Mining and Environmental at the University of Wollongong.

COMMUNICATION

The symposium was officially opened by Professor Paul Wellings, the Vice Chancellor of UOW and Professor Ge Shirong, President of CUMT. The symposium attracted more than 120 delegates from Australia, China and Poland. Headed by Professor Ge, CUMT sent a strong delegation of more 30 top professors and researchers to this event. In addition to overseas delegates, the symposium attracted Australian participants from CSIRO, CRC Mining, University of Queensland, Monash University, RMIT University and major coal operators including Peabody Energy, Glencore Xstrata, BHP Billiton. The forum included talks on the latest in mining technology, new techniques for the extraction of gas from coal seams, water management, subsidence minimisation and automation.

WORKSHOPS Workshop on Unconventional Natural Gas Developments: Challenges and Opportunities 21 February 2014 In Australia, sedimentary basins are rich in unconventional gas and undiscovered resource base. The most common types of unconventional gas resources are coal seam gas, shale gas, tight gas and gas hydrates. These gas reserves meet the demand for cleaner energy in many sectors, including the growing demand for power generation. Historically, these resources were overlooked in search of more economical and conventional gas reserves. To extract unconventional gas safely and without damaging the environment, we need to address a wide-range of technical and environmental issues. Development of innovative technology plays a key role in unlocking unconventional gas resource potential in an environmentally and economically sustainable way. The major aim of this workshop is to discuss the main issues and application of unconventional gas technologies accessible to a general technical audience while providing enough details for the practising scientist and engineer. Workshop on Transport and Energy Infrastructure 19 November 2014 This workshop focuses on the current challenges associated with transport and energy infrastructure development and acts as a platform to disseminate the most recent research and field advances to the engineering community. Presentations from leading experts, professionals, and industry specialists showcase technical advances and past experience related to infrastructure reliability. The workshop acts as a platform for attendees to share experiences, knowledge and to learn about the impact of emerging technologies.

90 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

PERFORMANCE INDICATORS

2013 – 2014 ANNUAL REPORT 91

Research Income CME SCHOOL RESEARCH INCOME($’000) The School of CME research income shows stable upward dynamics over the past 5 years, as the graph below depicts. The sources of research funding include ARC-Discovery, ARC-Linkage, ARC-DECRA, ARC Centre of Excellence, and ACARP funding schemes. Considerable amount of School’s research income also comes through direct industry-funded projects and International Collaborative Grants. 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 YEAR

2010 2011 2012 2013 2014

POSTGRADUATE COMMENCEMENT AND COMPLETION DATA Active HDR Students – School of Civil, Mining and Environmental YEAR Doctor of Philosophy

2008

2009

2010

2011

2012

2013

2014

Doctor of Philosophy (Integrated) Master of Computer Science - Research

Master of Engineering - Research

Master of Engineering (Faculty of Eng) - Research

4 3

1 14

Master of Philosophy Grand Total

Completed HDR Students – School of Civil, Mining and Environmental YEAR

PERFORMANCE INDICATORS

2008

2009

2010

2011

2012

2013

2014

Doctor of Philosophy

Master of Engineering - Research

2 1

Master of Engineering (Faculty of Eng) - Research Master of Philosophy Grand Total

1 4

92 SCHOOL OF CIVIL, MINING AND ENVIRONMENTAL ENGINEERING

2013 – 2014 ANNUAL REPORT 93

School of Civil, Mining & Environmental Faculty of Engineering & Information Sciences Tel: (02) 4221 3491 Fax: (02) 4221 5474 Email: eis@uow.edu.au University of Wollongong Northfields Ave NSW, Australia, 2522 Web: http://www.uow.edu.au

This brochure has been prepared by the University of Wollongong (UOW) for the purpose of providing industry, university partners and potential postgraduate students with research and admissions information. While every attempt has been made to ensure the accuracy of information at the time of printing, this information may change over time. UOW makes no warranty of any kind, express or implied, relating to the information provided in this brochure. Readers should rely on their own inquiries in making decisions affecting their interests. UOW CRICOS Provider No: 00102E