Page 1


The Bridge and Structural Engineer Indian National Group of the International Association for Bridge and Structural Engineering

Contents :

Volume 44, Number 1 : March 2014

Editorial • From the desk of Chairman, Editorial Board : Alok Bhowmick • From the desk of Guest Editor, S C Mehrotra

Highlights of ING-IABSE Events • Workshop at Patna, Bhopal & Hyderabad on “Movement of OWC/ODC” • Workshop at Pune • Annual Day 2014

(vii) (x) (xii)

1. The State of Codes on Structural Engineering in India Ashok K Jain

1

2. New Kolkata Airport Integrated Terminal Building Subhash Mehrotra, Deepak Thakur

8

3. Challenging Concrete Structure with a Blend of Architectural Fair Faced Concrete Vinay Gupta

14

4. The Growing Potential of Metal & Tension Structures for Infrastructure Development in India Prem Krishna

21

5. Case Study of Grand Arch.- The IREO Housing Vinod Jain

29

6. Analysis Approach to obtain EUDL Fire Tender Loading on Non-Tower Area of High Rise Group Housing Projects Abhay Gupta

36

7. Salient Planning, Design & Construction Features of Newly Constructed Multi Level Underground Automatic Car Park for 800 Cars at Kamlanagar, Delhi Achyut Ghosh, Alok Bhowmick, Shirish Mulmuley

43

8. Rapid Construction of Multistorey Buildings in India K K Nayar, Subhash Mehrotra, Deepak Thakur

56

9. Road Map Towards Net Zero Energy Building Minni Sastry

66

Information Section : Lectures during Annual Day 2014 1. Bridge Rehabilitation and Maintenance Works, Part-1 Eiji YONEZAWA 2. Bridge Asset Management, Part-2 Denichiro YAMADA

69

C o ntents

Special Topic : Building Structures

77

Research Papers 1. Incremental Dynamic Analysis of Reinforced Concrete Frames with Application on Grid Computing 85 A Melani, Rakesh Khare, Mahesh Shah, Pallavi Gavali 2. High Performance Cement Concrete Squat Shear Walls Under Reverse Cyclic Loading N Ganesan, PV Indira, P Seena

100

Panorama • About ING-IABSE • Office Bearers and Managing Committee Members 2014 • Minutes of the 101st Managing Committee Meeting of the ING-IABSE held at New Delhi on the 22nd March 2014 • Minutes of the 54th Annual General Body Meeting of the ING-IABSE held at New Delhi on the 22nd March 2014 • Report of Activities of ING-IABSE • Audit Report of ING-IABSE for the year 2012-2013 • Minutes of the 102nd Managing Committee Meeting of the ING-IABSE held at New Delhi on the 22nd March 2014 • ING-IABSE Membership Application Form

The Bridge and Structural Engineer

108 111 115 117 120 126 138 141

Volume 44

Number 1

March 2014  i


ii  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


March 2014

B&SE: The Bridge and Structural Engineer, is a quarterly journal published by ING-IABSE. It is one of the oldest and the foremost structural engineering Journal of its kind and repute in India. It was founded way back in 1957 and since then the journal is relentlessly disseminating latest technological progress in the spheres of structural engineering and bridging the gap between professionals and academics. Articles in this journal are written by practicing engineers as well as academia from around the world.

All material published in this B&SE journal undergoes peer review to ensure fair balance, objectivity, independence and relevance. The Contents of this journal are however contributions of individual authors and reflect their independent opinions. Neither the members of the editorial board, nor its publishers will be liable for any direct, indirect, consequential, special, exemplary, or other damages arising from any misrepresentation in the papers. The advertisers & the advertisement in this Journal have no influence on editorial content or presentation. The posting of particular advertisement in this journal does not imply endorsement of the product or the company selling them by ING-IABSE, the B&SE Journal or its Editors.

Front Cover : Mumbai’s New International Airport Terminal T2 The sparkling new terminal has been built by the GVK-led consortium. The four-storey terminal will cater to an estimated 40 million passengers annually. It has 188 check-in counters, 60 immigration counters for departing passengers, and 76 immigration counters for incoming fliers. The new terminal will have 2300 CCTV cameras for passenger safety and 4100 public address speakers. The X-shaped terminal also boasts of a three-kilometre-long art walk which incorporates Indian aesthetics with a white peacock theme. Titled ‘Jaya He’, it offers a glimpse into India’s rich legacy and is an unprecedented interdisciplinary platform for the nation’s cultural and creative industries.

Editorial Board Chair : Alok Bhowmick, Managing Director, B&S Engineering Consultants Pvt. Ltd., Noida

The Bridge & Structural Engineer, March 2014

Disclaimer :

Members : Mahesh Tandon, Managing Director, Tandon Consultants Pvt. Ltd., New Delhi A K Banerjee, Former Member (Tech) NHAI, New Delhi Harshavardhan Subbarao, Chairman and Managing Director, CCP Ltd., Mumbai Nirmalya Bandyopadhyay, Director, STUP Consultants Pvt. Ltd., New Delhi Jose Kurian, Chief Engineer, DTTDC Ltd., New Delhi S C Mehrotra, Chief Executive, Mehro Consultants, New Delhi Advisors : A D Narain, Former DG (RD) & Additional Secretary to the GOI N K Sinha, Former DG (RD) & Special Secretary to the GOI G Sharan, Former DG (RD) & Special Secretary to the GOI A V Sinha, Former DG (RD) & Special Secretary to the GOI S K Puri, Former DG (RD) & Special Secretary to the GOI R P Indoria, Former DG (RD) & Special Secretary to the GOI S S Chakraborty, Chairman, CES (I ) Pvt. Ltd., New Delhi B C Roy, Senior Executive Director, JACOBS-CES, Gurgaon Published : Quarterly : March, June, September and December Publisher : ING-IABSE C/O Secretary, Indian National Group of the IABSE IDA Building, Ground Floor (Room No.12) Jamnagar House, Shahjahan Road New Delhi-110011 India Phone: 91+011+23386724, 23782923 Telefax: 91+011+23388132 E-mail: ingiabse@bol.net.in, ingiabse@hotmail.com, secy.ingiabse@bol.net.in Submission of Papers : All editorial communications should be addressed to Chairman, Editorial Board of Indian National Group of the IABSE, IDA Building, G/F, Jamnagar House, Shahjahan Road, New Delhi – 110 011. Advertising : All enquiries and correspondence in connection with advertising and the Equipments/Materials and Industry News Sections, should be addressed to Shri RK Pandey, Secretary, Indian National Group of the IABSE, IDA Building, Ground Floor, Jamnagar House, Shahjahan Road, New Delhi-110011.

Journal of the Indian National Group of the International Association for Bridge & Structural Engineering

The Bridge and Structural Engineer

• Price: ` 500

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  iii


From the Desk of Chairman, Editorial Board

The current issue of B&SE journal is focused on the theme of ‘Building Structures’. ‘Building Structures’ are those manmade structures which are intended for human ‘use’ or ‘occupation’. The issue therefore covers residential, commercial buildings, Parking structures as well as Airport Buildings. There are a total of 9 technical papers and 2 research papers covered in this issue of the journal. Also included in this issue are handouts of two excellent presentation on Bridge Rehabilitation & Bridge Asset Management, made by Japanese Experts during the Annual Day of ING-IABSE held on 22nd March, 2014. Current structural design practice is primarily concerned with optimizing the construction time, cost and schedule of building project, while ensuring that the structure meets the basic safety and serviceability requirements. The adaptability in design, multi-functionality, reduction of maintenance cost, life cycle costing, need for low eco-footprint and other related sustainability issues are relatively new concepts and these concerns are hardly given any considerations in majority of the cases. It is increasingly recognized in structural engineering forums and political discourse, that many of the engineering practices that we follow, simply cannot be sustained indefinitely. We are exceeding the capacity of the planet to provide many of the natural resources

that we use. Emerging trend in structural engineering therefore is sustainable design, where energy conservation is the principal criteria for consideration. Sustainable design means designing in such a way that the natural resources are consumed in a controlled manner to ensure that they are available for many generations to come. Sustainable design considers the ecological, economic and sociocultural environments and works to balance all three. Our Guest Editor for this issue is Shri S C Mehrotra, Principal Consultant & CEO of M/s Mehro Consultants. He is one of the leading structural consultant of the country and well renowned. He is currently the President of Indian Association of Structural Engineers (IASE) and Chairman of the FIDIC membership committee and a well known personality in the field of structural engineering. We hope that this issue will help to disseminate the knowledge and information about design of Building Structures among the structural engineering fraternity. I hope readers will find these papers stimulating and informative.

ALoK BHoWMICK

iv

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


From the Desk of Guest Editor

This March issue of ING-IABSE is a special issue with focus on Building Structures. There is a wide variety of Building structures ranging from Multi-storeyed Residential to Office and Commercial Complexes, Institutional Buildings, Car Parking Structures, Metro Stations, Hospitals, Air terminals and other structures for Infrastructure development, Structures of National and International importance like the Parliament Library Building, Sports Complex Buildings etc. Each type of structure is subject to different criteria of loading ( dead, live, wind, earthquake loads etc).Importance factor and soil type also govern the design of structures. There are large numbers of structural elements in the building and the design has to cater to prevent progressive collapse of structure even if a single element fails. This is of prime importance in natural calamities like earthquakes, wind or terrorist attack where it is required to prevent the structure from collapse

to save human life. Recently, new international design criteria are being followed to cater for Blast Loads which could be due to internal explosion or due to Terrorist attacks. Some of the problems faced by structural engineers are due to our IS Codes. These codes take years to revise and many clauses are not clear and sometimes irrational. There is paper by Prof. Ashok K Jain of I.I.T Roorkee regarding “The State of Codes on Structural Engineering in India�. Dr. Jain has served on various BIS Committees since 1984 and his recommendations will go a long way to see new vision. Building Structures have large number of parameters, and this edition pertains to some of the most important aspects of structural design and typical case studies. I hope in future, some editions can take up other aspects of building structures.

S.C. MEHRoTRA

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014

v


Profile of S.C. Mehrotra Mr. S. C. Mehrotra is a post graduate in Structural Engineering from I.I.T. Delhi. His professional experience of 42 years includes structural designs for commercial and residential multistorey buildings, hospitals, malls, industrial structures, and public infrastructures, including 800 tall buildings in the storey range of 10 to 40 and 30 Airport terminal buildings. He has published many technical papers and his designs have won several prestigious awards. He is the Principal Consultant & CEO of M/s Mehro Consultants which is one of the leading structural Engineering Consulting Firms of India. He is the presently President of Indian Association of Structural Engineers (IAStructE). He was President of Consulting Engineers Association of India during the period December 2003 to December 2005. He was the first Indian and first South Asian who gotelected as Executive Committee member of FIDIC (International Federation of Consulting Engineers) for the period 2005 to 2009. FIDIC was established in 1913. Currently he is Chairman of FIDIC membership committee.

vi  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


HIGHLIGHTS oF THE WoRKSHoP oN “MoVEMENT oF oVER WEIGHT AND oVERDIMENSIoNAL CoNSIGNMENT (oWC/oDC)” HELD AT PATNA, BHoPAL AND HYDERABAD IN MAY & JULY 2013 1.

WoRKSHoP AT PATNA

The Indian National Group of International Association of Bridge & Structural Engineers (ING-IABSE) organized a half-day workshop on “Movement of Overweight & Over-dimensional consignment at Hotel Chanakya, Patna on 30th May 2013. The workshop was sponsored by the Hydraulic Trailers Owners Association (HTOA). The workshop was well attended by more than 60 delegates from various parts of the country. The proceedings of the Workshop consisted of welcome address by Chairman, ING-IABSE & ADG-MORTH (Shri V L Patankar) followed by address by Chief Guest, Secretary, RCD (Shri Pratyaya Amrit). After a brief coffee break, this was followed by presentations by 2 invited speakers. 1st presentation was made by Shri A P Pathak, CE(S&R), MORTH on “Movement of OWC/ODC on National Highways” and this was followed by a presentation by Shri Alok Bhowmick, Managing Director, B&S Engineering Consultants Pvt. Ltd. On “Effects of Overloading on Bridge Assets”. There was an interaction session after the presentations and the workshop concluded with a vote of thanks by Shri Manish Kataria, Secretary HTOA followed by Lunch. The workshop started with the Inaugural Session. The Chief Guest for the Workshop was Shri Pratyaya Amrit, Secretary, RCD, Patna, who presided over the Inaugural Session. Shri V L Patankar in his inaugural address explained the genesis of this Workshop and emphasised the need to disseminate the recent guideline issued by MORTH on 24th January 2013 with the objective of streamlining the approval process for granting of permission for passage of such OWC. He mentioned that this workshop is the first of a series of workshops that is planned by ING-IABSE all over the country for speedy implementation

The Bridge and Structural Engineer

of the MORTH guidelines on ODC/OWC. He also highlighted in his presentation the good works done by ING-IABSE in the past in dissemination of knowledge all over the country by conducting such seminars and workshops. He also emphasised that “Overloading” needs to be looked at not only in terms of how much load is being carried, but more importantly how it is carried. The deterioration caused in the road and bridge assets are more due to the inappropriate method of carriage of overloads and it is in this area where dissemination of knowledge is required. Shri Pratyaya Amrit, highlighted in his inaugural address the urgent need for conducting such workshops and thanked ING-IABSE in general and Shri V L Patankar in particular for the initiative taken in this regard and for choosing Patna as the venue for first such workshop. He hoped that the Workshop will enrich the knowledge base of the delegates and will help to not only expedite the approval process for passage of OWC/ODC but also will increase awareness of the delegates on safety aspects. Shri A P Pathak in his presentation explained that due to exponential growth in infrastructure sector, there is growing need for transportation of large overweight equipments, mainly in power sector and it was the need of the hour to formulate a policy for safe movement of such consignments in a time bound frame work. He gave the background, assumptions and the basis on which the MORTH guideline and the working charts were prepared. He explained in detail the applicability of the charts and it’s limitations. He also explained how the charts are to be used in actual practice. He explained the detailed procedure to be adopted for granting permission on OWC/ODC from MORTH. He also informed the delegates that for further smoothening the process of

Volume 44

Number 1

March 2014

vii


approval, the format for application, format for survey and inspection as well as sample format for presentation of results by the transporter is being evolved by MORTH and will be put on web site soon with the objective of smoothening the process. Shri Alok Bhowmick in his presentation explained that road safety is a major concern for India since as per the recent study, it is observed that fatality rates in India are 10 times those in the developed countries. He explained in his presentation how overloading effect bridges and what are the steps to be taken to manage overloading. He explained that there are two kinds of overloading. Distinction needs to be made between the illegal overloading which has very high frequency of occurrence and the legal permission for passage of OWC/ ODC, which are of infrequent nature and are necessary evil for the countries growth. He highlighted that use of multi axle hydraulic trailers for passage of OWC helps to spread the load over a large area and thus increases the safety of road and bridge assets. He also emphasised in his presentation the need to have a re-look into design loadings and

A view of the Dais during the Inauguration at Patna

viii

Volume 44

Number 1

March 2014

suggested that the National Highways, which constitutes only 1.7% of the road network of the country, but carries more than 40% of the freight traffic, should be designed for passage of OWC. He also suggested that MORT&H should implement a Bridge Management System and MORTH & State Governments shall join hands in creating a bridge management organization spreading over length and breadth of the country with dedicated & trained staff having well defined responsibilities. 2.

WoRKSHoP HYDERABAD

AT

BHoPAL

&

The Indian National Group of the IABSE also organized similar Workshop in co-operation with BHEL at Bhopal on 15th July 2013 and Hyderabad on 30th July 2013. These Workshops were attended by about more than 75 delegates from various Govt Department as well as other private and public organizations. The delegates who attended the Workshop mentioned that the subject matter of the Workshop on “Movement of Over Weight and Over Dimensional Consignment (OW/ODC)� is very timely.

Shri VL Patankar, Chairman, ING-IABSE delivering his address during the Inaugural Function at Patna

The Bridge and Structural Engineer


Shri VL Patankar, Director General (Road Development) & Special Secretary Ministry of Road Transport and Highways & Chairman, ING-IABSE lighting the traditional Inaugural Lamp along with high dignitaries at Bhopal

Another view during the inaugural function at Bhopal

Shri AP Pathak during his Technical Presentation

Shri Alok Bhowmick during his Technical Presentation

A view of the audience during the Technical Presentation

Another view of the audience during the Technical Presentation

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014

ix


HIGHLIGHTS oF THE WoRKSHoP oN “DETERMINATIoN oF SAFE BEARING CAPACITY oF CoHESIVE & NoN-CoHESIVE SoIL AND DESIGN oF DIFFERENT TYPES oF FoUNDATIoNS FoR BRIDGES” HELD AT PUNE (MAHARASHTRA) oN 21ST AND 22ND FEBRUARY 2014 The Indian National Group of IABSE in cooperation with National Highways Authority of India – RO Maharashtra successfully organised two day Workshop on “Determination of Safe Bearing capacity of Cohesive and NonCohesive Solid and Design of different types of Foundations for Bridges” at Pune (Maharashtra) on 21st and 22nd February 2014. The Workshop was attended by about 65 delegates. The aim of the workshop was to provide a unique opportunity to the practicing engineers to interact with experts for dissemination of knowledge and experiences relating to Development of Bridges. Participation of delegates in floor intervention and discussions was very encouraging.

Cohesive Solid and Design of different types of Foundations for Bridges” was addressed by three experts viz. Dr V K Raina, Dr S S Bhosale and Dr S D Limaye covering the following themes:

The Workshop was inaugurated by Shri V L Patankar, Director General (Road Development) & Special Secretary to the Govt of India, Ministry of Road Transport and Highways by lighting the traditional lamp Other dignitaries, Shri A B Pawar, D O Tawade, Dr V K Raina and Shri R K Pandey also graced the occasion. Shri D O Tawade, Chief General Manager (Tech) & RO Maharashtra extended warm welcome to the participants of the Workshop. Shri V L Patankar, Chairman, ING-IABSE delivered his address during the Inauguration. Shri R K Pandey, Secretary, ING-IABSE proposed Vote of Thanks.

1.

“Practising Professional’s method for Estimating the Bearing Capacity of Cohesive and Non-cohesive substrata under different types of Foundations – Open, Caisson & Piles” by Dr V K Raina, Consultant (World Bank).

2.

Laboratory and Field Tests of Soil Explorations for Bridge Foundations by Dr S S Bhosale, Professor and Head, Department of Civil Engineer, Pune

3.

“Conceptualization and Construction of three important Bridges on Konkan Railway Projects” by Dr S D Limaye

The concluding remarks of the Workshop were presented by Shri D O Tawade, Chief General Manager, NHAI on 22nd February 2014 (forenoon). The delegates who attended the Workshop mentioned that the subject matter of the Workshop on “Determination of Safe Bearing capacity of Cohesive and Non-Cohesive Solid and Design of different types of Foundations for Bridges” is very timely. The Workshop was a great success.

The Workshop on “Determination of Safe Bearing capacity of Cohesive and Non-

x

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Shri VL Patankar, Director General (Road Development) & Special Secretary, Ministry of Road Transport and Highways & Chairman, ING-IABSE lighting the traditional Inaugural Lamp along with high dignitaries

A view of the dais during the Inaugural Function

Shri DO Tawade, Chief General Manager (Tech) & RO Maharashtra, NHAI Delivering his address during the Inauguration

Shri RK Pandey, Secretary, ING-IABSE & Chief Engineer (Planning) Delivering his address during the Inauguration

Shri VL Patankar Chairman, ING-IABSE and Director General (Road Development) & Special Secretary, Government of India Delivering his welcome address during the Inauguration

A view of the audience during the Technical Presentation

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014

xi


HIGHLIGHTS oF THE ING-IABSE ANNUAL DAY-2014 AND TECHNICAL PRESENTATIoNS HELD oN 22ND MARCH 2014 AT NEW DELHI

The Indian National Group of the IABSE had organised its Annual Day-2014 along with technical presentations on “Bridge Rehabilitation and Maintenance Works” by Shri Eiji YONEZAWA and Shri Denichiro YAMADA (JICA Survey Team) and “Making of Mumbai International Airport Project (MIAL) by

Shri Rajesh Kanade, Head- Project Planning and Control, Larsen & Toubro Ltd at India International Centre, Lodhi Road, New Delhi on 22nd March 2014. The Annual Day 2014 and presentation was attended by about 70 delegates from various parts of India. The presentation was highly acclaimed.

A view of the Dais during the Inauguration

Shri Eiji YONEZAWA during his Technical Presentation

Shri Denichiro YAMADA during his Technical Presentation

Shri Rajesh Kanade during his Technical Presentation

xii

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


A view of the audience during the technical presentation

A view of the audience during the technical presentation

Managing Committee Members. In the 102nd Managing Committee meeting, the elections were held for Members of the Executive Committee. Shri V L Patanakr was elected as Chairman, Shri V K Gupta, Shri B N Singh, Shri Dr Harhavardhan Subbarao and Shri Surjit Singh were elected as Vice-Chairmen of the Group. Shri R K Pandey and Shri Ashish Asati would continue to act as Secretary and Director of the Group.

Shri RK Pandey, Secretary ING-IABSE Proposing a Vote of Thanks

Besides the above, the following Annual Meetings of the Group were also held on the 22nd March 2014 at India International Centre, New Delhi. •

101st Managing Committee

54th Annual General Body

102nd Managing Committee

In the 54th Annual General Body Meeting, elections under different rules were held for

The Bridge and Structural Engineer

A view of the Dais during the 101st Managing Committee meeting

Volume 44

Number 1

March 2014

xiii


A view of the audience during the 54th Annual General Body Meeting

A view of the audience during the 102nd Managing Committee meeting

FoRTHCoMING EVENTS oF ING-IABSE 1. The Indian National Group of the IABSE is organizing a Seminar on “Elevated Transport Corridors” at Mysore (Karnataka) on 21st and 22nd June 2014. The Seminar will have five Technical sessions covering each theme in one Session as per themes and programme as under: Technical Session-1

“Planning and Project Preparation”

Technical Session-2

“Economic Feasibility Financing Option”

Technical Session-3

“Construction”

Technical Session-4

“Operation and Maintenance”

Technical Session-5

“Case Studies”

Technical papers under various themes are invited for inclusion in the Seminar Report. The paper should be neatly printed including figures, tables etc. on A4 size paper with 25 mm margin on all side using 11 size Font (ARIAL) typed on one side only in available area. Those who are interested to contribute a paper, kindly send their paper (maximum 9 pages plus one cover sheet) by 30th May 2014 at the following address. Selected authors will be invited to present their papers in the Seminar. Shri RK Pandey Secretary Indian National Group of the IABSE IDA Building, Jamnagar House Shahjahan Road New Delhi-110011 Tel: 011-23782923, 23386724, Telefax: 011-23388132 E-mail: ingiabse@bol.net.in, ingiabse@hotmail.com 2. Regional Workshop on “Code of Practice for Concrete Road Bridges: IRC:112” to be held at Kolkata on 11th and 12th July 2014.

xiv

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


THE STATE OF CODES ON STRUCTURAL ENGINEERING IN INDIA

Ashok K. JAIN Professor of Civil Engineering Indian Institute of Technology Roorkee 247667 INDIA ashokjain_iitr@yahoo.co.in

Summary Structural engineering is the back bone of Civil Engineering and infrastructure in any society. It is crucial that all the codes related to structural engineering are based on principles of mechanics, and experimentally verified.They should be logical, rational and efficient, and should be revised as frequently as necessary. This paper highlights some of the significant discrepancies & shortcomings in our codes. It takes about 10 to 20 years to revise any code even based on copy and paste technology where the logic and continuity gets lost. It causes huge embarrassment and confusion to the code users. It is recommended that India should adopt any of the code in full from amongst some of the finest international codes along with commentary. A national annexure can be appended to address the local practices and other issues. Performance based codes need to be introduced at the earliest so that our engineers may compete globally. Keywords: Code, Concrete, Earthquake, Structural engineering, Steel, Shear wall, Water tanks

1. Introduction Each society has developed its own guidelines on how to construct safe houses/structures in its own ways from times immemorial based on its own experiences with materials, construction practices and nature. Over the last century each code has evolved based on scientific and technical inputs. In India, it is an open fact that there is no fundamental and focused research in structural engineering field including earthquake engineering. Since independence, it can be The Bridge and Structural Engineer

Ashok K. Jain, born 1950, received civil engineering degrees from the University of Roorkee and Michigan Ann Arbor, USA. He is a former Director, MNIT,Jaipur. His research area is nonlinear behaviour of steel and concrete structures.

safely stated that no research paper has come out from any of the premier teaching or research organizations that changed the course of thinking or understanding of any of the basic structural elements: bar, beam, slab, wall, column and beam-column joints – be it is in concrete or steel.To be fair, it is important to mention that the Government of India is pouring millions of Rupees in research through its various central and state agencies. The impact of research in Structural Engineering and, therefore, on codes is still invisible. Table 1: Important Codes on Structural Engineering Name of Code

Current Year 2000 2007 1987 2012 2002, 2005 2009

Previous Revision 1978 1984 1964 1980 1984 1965

IS:456 IS:800 IS:875 Part 3 IS:1343 IS:1893 Part 1,3,4 IS:3370 Parts 1 and 2 IS:4326 2013 1993 IS:13920 1993 NA IRC 6 2014 2000, 2010 IRC: 18 and 21 2011 as IRC 2000 112 The author served on various BIS committees since 1984 – IS:456, IS:800, IS:1893, IS:3370 and IS:13920 etc.[1,2,4,5,7]. In India, It takes any thing from 10 to 20 years to revise a code even with the copy and paste technology. Table 1 summarizes the state of revision of some of Volume 44

Number 1

March 2014  1


our most important codes. The Indian Roads Congress revised IRC 18 and 21 in 2011 and introduced the concept of limit state design. The concept of Ultimate load theory in concrete and steel structures was introduced in UK and USA in the early seventies. The limit state design in steel structures was introduced in India in the late 2007 and IRC 24 [8] was revised in 2010. Obviously, the working stress method of IS:8002007 is still very much in vogue. The earthquake engineering codes IS:1893 and 13920 [4,7] are far away from ground reality. Non-linear response spectra based on ductility levels is still missing. Same is the state of recently revised IS:3370 in 2009 [5].Each code committee looks West and adopts one or more British, European or American codes depending upon the taste of Convener and members. The next step is to make that code look different from the original and adapt it to suit the so called Indian conditions.This apparently leads to copy and paste technology where the logic and continuity gets lost. The sufferer is the Code user – student, teacher and professional engineer as well as local city authorities. The purpose of this paper is to highlight some of the significant discrepancies and shortcomings in the Indian codes that become the source of embarassment and confusion for the structural engineer. Hopefully, it would lead to better codes based on basic principles and logical thinking, that give more freedom and flexibility to the owners, designers and builders and improve the performance of a structure under a severe loading.

2. Issues of Concern in Codes 2.1 IS:456, IS:1343 and IRC 112 on Reinforced Concrete Structures India is the only country that has two separate codes IS:456[1] and IS:1343 [3] on reinforced concrete and prestressed concrete and another code on ductile detailing. IS:1343 code on prestressed concrete has been revised in 2012 but the entire limit state design part remains untouched. In 1996, the Code committee recorded a decision to integrate IS:456, IS:1343 and IS:13920 on the lines of ACI 318 but this decision is yet to be implemented even after 20 years. IRC 18 and 21 were apparently based on 2  Volume 44

Number 1

March 2014

IS:456 and IS:1343. The Indian Roads Congress has recently updated IRC 18 and 21 and issued IRC112-2011 [9] that deals with all aspects of concrete in a single code. It is a very long overdue and welcome change. It is based on Eurocode 2 which is quite different than IS:4562000 and IS:1343-2012. In IS:456 and IS:1343, the sections on shear and torsion kept changing from 1964 edition to 2002 edition without any compelling reason. 2.1.1 Shear Design In IS:456-1964, once the shear force exceeded the permissible value, the shear reinforcement was required for the total shear rather than the additional value. In IS:456-1978, the shear reinforcement was required only for the shear that exceeded the shear capacity of concrete. Now in IRC112, the shear reinforcement is again based on the total shear rather than the additional value. Apparently, the designer is left baffled! IS:456-1964

Design shear = V

IS:456-2000

Design shear = V – ιcbd

IRC 112-2011

Design shear = V = VEd

Asw VEd ≥ (1) x zσ ywd cot θ 2.1.2 Torsion In IS:456-1964, the design for torsion was based on membrane theory. In IS:456-1976, an empirical equation was introduced that was unique to the Indian code that required the calculation of equivalent bending moment and equivalent shear force. There was no mechanics or logic behind this formulation. It continues even today. Now in IRC 112, torsion clause has again been revised based on the membrane theory.The torsional resistance of sections is calculated on the basis of a thin-walled closed section in which equilibrium is satisfied by a closed shear flow. Solid sections may be modeled by equivalent thin-walled sections. Complex shapes, such as T- sections, may be divided into a series of subsections and the total torsional resistance taken as the sum of the capacities of the individual elements. The membrane theory is more logical and should never have been discontinued in IS:456 and IS:1343. The Bridge and Structural Engineer


2.2 IS:800 on Steel Structures Two issues of concern are brought out in IS:800 code [2]. 2.2.1 Compressive Strength of Axial Members The 1962 edition made use of the well known Secant formula to determine the permissible axial stress in a compression member: For kL/r < 160

   σy  1  ( 2a )  σa = λ  ec kL λσ a  ) 1 + r 2 sec( r 4 E  For kL/R>160

σ a = σ a (1.2 −

kL ) (2b) 800r

The 1984 edition made use of the little known Merchant-Rankine formula to determine the permissible axial stress in a compression member:

(

1 n 1 1 ) = ( ) n ( ) n (3) λσ a σe σ y

where, n = imperfection factor; λ= factor of safety It was possible to generate multiple column curves by adopting different values of imperfection factor n.The 2007edition has made use of the following formula from Eurocode 3 to determine the permissible axial stress in a compression member:

σ cd =

σ y / γ mo φ + (φ 2 − λ 2 )0.5

( 4a )

φ = (1 + a (λ − 0.2) + λ 2 )(4b) λ=

σy σ cc

(4c)

a = imperfection factor σcc = Euler buckling stress It is possible to derive it from the basic principles. Depending upon the imperfection factor α, it The Bridge and Structural Engineer

is possible to derive multiple column curves. The point of concern is why change the basic formula to determine the buckling strength of an axial compression member from one revision to other when each one of them leads to the same result (within + 5%)? This is very confusing for a designer. 2.2.2 Design and Detailing of Frames for Earthquake Loads Chapter 12 of IS:800-2007 [2] has the following clause: 2.2.3 Ordinary concentrically braced frames (OCBF) should be shown to withstand inelastic deformation corresponding to a joint rotation of at least 0.02 radians without degradation in strength and stiffness below the full yield value. Ordinary concentrically braced frames meeting the requirements of this section shall be deemed to satisfy the required inelastic deformation. 2.2.4 Special concentrically braced frames (SCBF) should be shown to withstand inelastic deformation corresponding to a joint rotation of at least 0.04 radians without degradation in strength and stiffness below the full yield value. Special concentrically braced frames meeting the requirements of this section shall be deemed to satisfy the required inelastic deformation. Nowhere in IS:800-2007 code, it has been explained what is the source of these two clauses nor how to compute the inelastic deformations in a joint; how to model a non-linear steel structure; how to apply the loads etc. There is no reference to convince that meeting the requirements of this section shall satisfy the required inelastic deformation? These clauses do not appear in EC3 from where the rest of the code has been drafted. 2.3 IS:1893 on Earthquake Force Three issues of concern are brought out in IS:1893 code [4]. 2.3.1 Approximate Period

Fundamental

Natural

IS:1893-1984 gave two equations for determining the fundamental natural period of vibration for moment resistant buildings and shear wall buildings as follows: Volume 44

Number 1

March 2014  3


a)

For moment resisting frames without bracing or shear walls for resisting the lateral loads

T = 0.1 N (5a)

b)

For all other buildings T=

0.09 H (5b) D

IS:1893-2002 Part 1 introduced the following formula to determine the approximate fundamental natural period of vibration (T) in seconds of buildings by the empirical expression: For moment resistant steel buildings without masonry in-fills T = 0.085 H0.75 (6a) For moment resistant concrete buildings without masonry in-fills T = 0.075 H0.75 (6b) For moment resistant buildings with masonry infills and shear wall or steel braced buildings â&#x20AC;&#x201C; Eq. 5b. In India, most of the multistory construction is moment resistant RC frames with masonry infills. If the period of vibration is computed using Eq 5b, the period is reduced significantly. This in turn increases the base shear by a factor of 2 to 3. This leads to two problems: 1.

2.

The design member forces increase significantly. Many private consultants in various parts of the country are openly flouting this provision. Perhaps, the designer is convinced about the safety of the building even by violating the code and taking a shelter behind the previous codal practice (IS:1893-1984). Some of the faculty members of IITs are party to this practice because they approve the design while proof checking. The more fundamental question is whether the current level of seismic forces is justified especially in seismic zone III and IV. The historical data about the occurrence of earthquakes or the damage to buildings during the past earthquakes do not convince the designers that there is a need to design the buildings for a higher lateral force. During the revision of seismic map in the current code, there was very strong objection and resistance from the Consulting engineers of Mumbai region for putting Mumbai in seismic zone III from zone II.

4â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The seismic map of India is based on very scanty data. Therefore, until the seismic zoning is done on a more rational basis, such violations are likely to continue. Even the proposed probabilistic seismic zoning map (draft 2013) is very close to that given in IS:1893-2002-part 1. Is it not surprising? Apparently, something is fundamentally missing. 2.3.2 Flat Slabs In Seismic Zones The flat plate structure is an economical and widely used form of construction in non-seismic areas especially for multistory residential or parking construction. Its weakest feature, as is well known, is its vulnerability to a punching shear failure at the slab-column junctions. The collapse of a number of buildings using such a system during the 1964 Anchorage, Alaska and the 1967 Caracas, Venezuela earthquakes, as well as several buildings using waffle slabs during the September 1985 Mexican earthquake, clearly dramatized this vulnerability. The 1994 Northridge earthquake caused the collapse or partial collapse of at least two parking structures that could be attributed primarily to the failure of interior columns designed to gravity loads only. IS:1893 and IS:13920 both are silent about the use of a flat slab in seismic areas. However, a note is provided in clause 7.11.2 in IS:1893 on the deformation capability of non-seismic members as follows: For instance, consider a flat-slab building in which lateral load resistance is provided by shear walls. Since the lateral load resistance of the slab-column system is small, these are often designed only for the gravity loads, while all the seismic force is resisted by the shear walls. Even though the slabs and columns are not required to share the lateral forces, these deform with rest of the structure under seismic force. The concern is that under such deformations, the slab-column system should not loose its vertical load capacity. There is a need to bring this note in the main body with appropriate caption to attract seriousness. The columns of the flat slab must be designed for P-delta effects as per 7.11.2 of IS:1893-part-1. The detailing of connection between shear walls and the flat plate system needs serious attention. The Bridge and Structural Engineer


The ACI 318 and Canadian code are very specific in this regard. 2.3.3 Response Reduction Factor R The response reduction factor assigned to different types of structural systems reflects design and construction experience, as well as the evaluation of the performance of structures in major and moderate earthquakes. It endeavors to account for the energy absorption capacity of the structural system by damping and inelastic action through several load reversals. Types of construction that have performed well in earthquakes are assigned higher values of R. The values of R vary between 1.5 and 5. On the issue of response reduction factor R in the Indian code, there are two problems: 1.

Response reduction calibration factor

factor

vis-à-vis

2.

Conflict in R values among different parts of IS:1893-2002

The Code committee borrowed the concept of response reduction factor R from the SEAOC Code of California/UBC. However, while writing IS:1893 – 2002, they deviated and instead used the factor R as a calibration factor with respect to the base shear in IS:1893-1984. No exercise was ever done to determine the response factors for different structural systems based on their non-linear behaviour. The Committee was very careful not to increase the level of base shear for buildings from 1984 to 2002 edition. The zone factor Z and the constant 2 were chosen out of judgment and calibration. Thus, no attention was paid to the real character of R. The second problem arose when other parts of IS:1893 were undertaken for revision. Notably, water tanks, bridges, chimneys and industrial structures. Overhead water tanks are inverted pendulum type structures. Some professional think they are very brittle systems and, therefore, need low R factors. However, during the past 6-7 decades, water tanks designed in accordance with IS:1893 – 1984 or earlier editions have performed quite satisfactorily during the earthquakes. After the Bhuj earthquake of 2001, in a few tanks, some horizontal cracks were observed in shell staging at the construction joint levels. There is hardly any report of failure of a water tank during The Bridge and Structural Engineer

an earthquake in India.The Code Committee recommended the R factors for the over head water tanks between 3.5 and 4.5. Obviously, an anomaly arose between the behaviour of a ductile framed structure and overhead water tank supported on ductile RC framed structure. The question is whether the nonlinear response of these two systems is close or quite different? Had the Committee followed a systematic approach or not called the factor R as a response reduction factor but a calibration factor, then there would have been no or less confusion and controversy. 2.4 IS:3370 on Liquid Retaining Structures IS:3370-2009 [5] based on British Code BS:8007 – 1987 has introduced many drastic changes over its 1965 edition. Some of them are shown in Table 2.The Committee appeared to be overwhelmed by the term “Limit State Design” for the containers. Also, it did not realize that the climate in England is quite different than that of India. Moreover, there are several lakhs overhead tanks, underground water tanks, water treatment plants and sewage treatment plants throughout the country. There was no need to borrow the specifications from any foreign code. A workshop was organized at the I.I.T. Roorkee in 2005 on the revision of IS:3370. Many senior engineers from U.P. Jal Nigam, Haryana Jal Nigam and other states participated. There was absolutely no problem reported from any part of the country as far as shortcoming in the design specification was concerned. Yes, it is true that a few OHT had failed during the initial water testing. But the cause of failure was poor workmanship rather than deficiency in design specification. Its recommendations were sent to the BIS. The Committee did not pay any attention to the recommendations of this workshop. Thus, unnecessary drastic cost escalation and burden on natural resources have come as a consequence of this revision. Moreover, it is not easy to design an Intze or circular water tank based on limit state of collapse because of irregular shape of the container and non availability of expressions to compute deflection of such members. The only revision that would have sufficed was an increase of concrete grade from M20 to M25 for Volume 44

Number 1

March 2014  5


water tanks, and M20 to M30 or M35 for sewage treatment plants from durability considerations and equations for crack width etc. The working stress method for liquid retaining structures is essentially a limit state of serviceability condition for no crack. Similarly, there is a tendency to increase the thickness of shaft of the tank as well as provide reinforcement in four layers

simply because a few water tanks collapsed during the testing stage. Several water tanks on shaft staging in single layer reinforcement built in 1970s are still doing well. Did anybody try to find out the real reason of the failure of such tanks? Whether the real cause of collapse was poor workmanship and materials rather than a design defect?

Table 2: Comparison of changes in IS:3370 in 2009 and 1965 editions Clause on

2009

1965

Minimum Grade of Concrete, Clause As per severe exposure 4 of Part 1 condition, that is, M30

M20

Minimum reinforcement

0.35% of the surface zone 0.24% of the cross-sectional area; for sections greater than 100 mm but less than 450 mm, minimum steel reduced from 0.24% to 0.16%.

Minimum cover to steel

As per severe exposure condition, that is, 45 mm

Permissible tensile stresses in Steel: On the liquid face 130 MPa Away from liquid face same

Greater of 25 mm or bar dia

150 MPa 190 MPa

2.5 IS:13920 on ductile detailing of concrete structures

is a need to revise IS:13920 to make ductile detailing more rational and economical.

IS:13920[7] requires many structural changes. Some of them are as follows:

2.5.2 Column Vs. Shear Wall

2.5.1 Uniform ductile detailing across all seismic zones, type of building and importance In IS:1893 code of 1962 and 1966, there were seven seismic zones that were reduced to five in 1970. In any zone, there are buildings having varying degrees of occupancy, utility, and risk level. IS:4326-1976 and also 2013 edition [6], divided masonry buildings in five categories depending upon their design seismic coefficient, and prescribed ductile detailing. At present, IS:13920 stipulates only one ductile detailing for all kinds of buildings in any seismic zone. Now to detail each building, in each seismic zone, similarly and uniformly, across the board is not fair and logical. The ACI code specifies different detailing based on seismic design category from A to F of a building. Similarly, the Eurocode EC8 specifies low, medium and high ductile class (DCL, DCM, DCH) for various buildings. There 6â&#x20AC;&#x192; Volume 44

Number 1

March 2014

A wall has not been defined in the code. If a member is not a column, obviously it is a wall. The intention of this clause was to discourage elongated columns, that is, columns having sizes such as 230 mm x 2000 mm etc. Such members are modeled as columns and also designed as columns. Only in the detailing stage, the concept of a wall creeps in. The minimum reinforcement in vertical and horizontal direction is 0.25% each. In the case of columns, the minimum vertical reinforcement is 0.8% of the area required. There is a need to replace the aspect ratio for columns from 0.40 to 0.25. This will help accommodate steel bars in the beam-column joint much better. The beam-column joints need due attention. It is a usual practice to compute special confinement reinforcement as per Clause 7.4 and provide it near the top and bottom of the column. In the middle portion, the above spacing is usually doubled. However, in some cases this The Bridge and Structural Engineer


doubling of spacing may not be sufficient to meet the requirements of 0.25% lateral steel. Clause 7.4.3 requires that if the calculated point of contra flexure is not within the middle half of the storey, special confinement reinforcement need to be provided over the full height. The author in his 35 years of experience has yet to come across a designer who has time and intention to explore the point of contra flexure in a column? There is a need to rationalize such clauses.

3. The Future of Codes â&#x20AC;&#x201C; Prescriptive Design Vs. Performance Design At present all Indian codes are based on prescriptive design criteria. In the prescriptive design, the Code tells the designer what to do at each stage. The final product is expected to respond as the Code desired. The designer is not bothered about the final performance of its product. It is presumed to behave as the Codes have envisaged without knowing what exactly the Codes have desired or intended. Whereas in the performance based design, the Code simply tells what performance is expected out of the given component of the structure as well as the structural system. A performance based design code can be expected to be a probabilistic code. The designer has to choose an appropriate option how to design it so as to achieve the specified performance level and probability. Thus, the designer has to have a very deep and clear understanding of the behavior of various structural materials, components and structural systems under different loading conditions, their implications and consequences.

detailing in IS:13920; arbitrary increase in grade of concrete, cover, minimum steel and decrease in permissible stress in IS:3370. There should be no manipulations with the basic principles. This will help the designers to focus on the logic rather than on arbitrariness. Some clauses have been picked up randomly from foreign codes without any continuity. The copy and paste technology is not only degrading; it is also leading to very awkward situations for the structural designers. How to explain the rational to more inquisitive young minds? In the absence of dedicated basic research in India, it is obvious that rational codes cannot be developed indigenously. Therefore, one solution is to adopt one of the finest international codes of practice in full along with its commentary. There should be an Indian national annex to the code to address the local conditions and other issues. The code commentary will be very useful for understanding the rationale behind any given clause. The introduction of performance based design will help our designers to compete globally.

5. References 1.

IS 456:2000 Plain and Concrete, BIS, New Delhi.

2.

IS 800:2007 General Construction in Steel, BIS, New Delhi.

3.

IS 1343:2012 Prestressed Concrete, BIS, New Delhi.

4.

It is believed that the Indian Codes will adopt the performance based specifications in the near future in the interest of rational and innovative design.

IS 1893:2002 Criteria for Earthquake Resistant Design of Structures, Part 1 General Provisions and Buildings, BIS, New Delhi.

5.

IS 3370:2009 Liquid Retaining Structures, Parts 1 and 2, BIS, New Delhi.

4. Concluding Remarks

6.

IS 4326:2013 Earthquake Resistant Design and Construction of Buildings, BIS, New Delhi.

7.

IS 13920:1993 Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces, BIS, New Delhi.

8.

IRC 24:2010 Steel Bridges, IRC, New Delhi

9.

IRC 112:2011 Concrete Road Bridges, IRC, New Delhi.

This paper summarizes the state of some of the important and most frequently used codes on structural engineering in India (IS:456, IS:800, IS:1343, IS:1893, IS:3370, IS:13920, and IRC 112). There is no apparent logic for flip flop from one edition of a code to another in describing the torsion in concrete codes, buckling strength in steel code; seismic zoning, time period and response factor R in IS:1893; uniform ductile The Bridge and Structural Engineer

Volume 44

Number 1

Reinforced

March 2014â&#x20AC;&#x192; 7


New Kolkata Airport Integrated Terminal Building

Subhash MEHROTRA Principal Consultant & CEO Mehro Consultants New Delhi, India, scmehrotra@mehroconsultants.com

Subhash Mehrotra, born in 1949, received his M. Tech (Structural Engineering) degree from I.I.T. Delhi. He is President of IAStructE. He was past President of CEAI. He is currently Chairperson of Membership Committee of FIDIC.

Summary Spread over an area of 1670 acres, new Kolkata airport is the largest airport in Eastern India and the only International airport operating in West Bengal with considerable potential to develop into an international hub in South East Asia. This is a New Asset for eastern region and will boost the economy of the region and give benefits to the society and the country as a whole. This modern air terminal in glass, structural steel and concrete has been designed andconstructed with world class passenger facilities. The building has large column free spaces and the span of trusses varies from 81 to 90 meter with cantilever projection up to 27 meter on city side and 18 meter on Air side.This was a technological challenge which was met with innovative section and erection methodology. Keywords: Lens Trusses, Steel Lattice Towers, Folded Plan

1. Introduction New Kolkata Airport named as Netaji Subhash Chandra Bose International Airport is located at Dum Dum. It is a joint feat of Architecture and

8â&#x20AC;&#x192; Volume 44

Number 1

March 2014

Deepak THAKUR Principal Consultant Mehro Consultants deepakthakur.mehro@gmail.com

Deepak Thakur, born 1959, received his B. E. Civil Engineering from Nagpur University. He is fellow Member of IAStructE. He was former Superintending Engineer at CPWD.

Structure. It is the fifth busiest airport in the country and presently handling over 9.0 million passengers annually and designed to cater for 20 million passengers annually in the future. Two international architects M/s RMJM, Singapore for domestic and M/s Adp.i, France for International wing were involved. The two Indian architects M/s Virendra Khanna Associates for International and M/s Sikka Associates for domestic wing were involved in the architectural design. Our firm Mehro Consultants was involved for structural design for both Domestic and International wing. The new building has built up area of 2.0 million sq. ft of the main building and 0.6 million sqft of underground parking.

2. Structural System The new air terminal building has a folded plan shape separating the domestic and international wing (Fig.1 and 1a). Average length of the domestic wing is about 324 meter and that of international wing is 216 meter. Expansion joints have been provided every 54m. The building has a normal width of 144 meter throughout.

The Bridge and Structural Engineer


Fig. 1: Folded Plan Shape

Fig. 1a: Architectural Plan of Arrival Level (0.00 level)

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014

9


The structure is RCC (Reinforced Cement Concrete) framed structure with the grid size of 18m x 18m (Fig. 2) supporting RCC slabs and steel trussed 3-Dimensional roof. Seismic loading has been considered as per IS: 1893 (Part-1) 2002. Wind forces have been catered as per IS 875 (Part-3) 1987.

check-in and departure. Part of first floor has mezzanine floors to accommodate airline and other offices. The roof is a 3-Dimensional steel trussed space structure varying in height and configuration from level +21.5 mtr to a maximum of 31.65 meter.

The building has been analyzed as a 3-dimensional skeletal structure of beam column frame structure. Foundation is bored cast in-situ piles of dia 600mm to 1000mm and depth varying from 16meter to 40 meter.

Fig. 3: Structural Levels

Fig. 2: Planning Grid 18x18 m for RCC framed structure

Photo 1: City Side with maximum cantilever Projection 27m and Folded shape

Fig. 2a: Blown up section from, Fig. 2: for RCC framed structure

The structure has four levels (Fig. 3), one basement at -7.3 meter that accommodates baggage handling. The ground level at +0.0 meter accommodates passenger arrival & baggage claim. First floor at 9.5 meter handles passenger

10â&#x20AC;&#x192; Volume 44

Number 1

March 2014

Photo 2: Large Column free spaces inside the terminal

The Bridge and Structural Engineer


3.

Structural Roof

The roof structure covers an area of approximately 21,400 Sqm. The structural arrangement has been developed to provide a large column free space over the length of the building as well as to provide the distinctive concave profile for the ceiling line. (Fig. 4& Fig. 6)

columns, located within the landscaped strip adjacent to the departure gates. The roof structure and its supports are constructed from high strength structural steel of grade 355 and 310 N/ mm2 fabricated from Rolled Hollow Sections and are suitably protected against corrosion.Each Truss is of length 135 m.

LATTICE TOWER

Fig. 4: Curved Profile of supports determining span of each truss

The two main components that comprise the structural system are listed below: •

Lens Trusses

Lattice Tower

4.

Lens trusses

The structural arrangement employs a series of large lens-trusses (Fig. 5 and Fig. 7) at approximately 18m centers to support the roof. The trusses are supported by lattice towers located within the curved line of the entrance façade (Fig. 4 and Fig. 5) and at rear by RCC

Fig. 5: Lens Trusses with centre to centre distance 18m

The Bridge and Structural Engineer

Photo 3: City side façade view during construction showing curved support profile

Due to the curvature of the entrance façade, the clear spans of trusses vary from 81m to 90m with cantilever projection upto 27 meters on city side and 18m on Air side (Fig. 6) based on their location in plan. The large span of trusses enables large column free spaces inside the airport terminal The lens truss has trapezium cross section with a maximum depth of 4.5m at its mid-span (Fig. 7). The profile of the curve has been designed to also provide sufficient depth over the supports to resist the cantilever forces. Those parts of trusses, which project above the concave roof, are glazed to facilitate day lighting.

Fig. 6: Longitudinal section through Truss

Volume 44

Number 1

March 2014

11


Fig. 7: Trapezium Cross Section of Lens Truss

5.

Lattice tower

The lattice towers are built-up steel columns that have two main structural functions: •

To support the Lens-Trusses

To support the glazing system and wind forces

Photo 4: Erection of Lattice Tower

The towers are in the form of an open box-frame with the rear columns of the tower carrying the load from the lens-trusses. The tower act as vertical Vierendeel trusses in order to resist the high wind loads imposed on the façade. ( Fig. 8)

Photo 5: Lattice Towers curved profile at city side of terminal

6.

Roof construction methodology

and

erection

l

The design of the trusses is developed around a construction method compatible with the local conditions and site constraints.

l

It was envisaged that the lens-truss would be fabricated off-site in segments to allow delivery to the site.

l

The segments were assembled on site under controlled survey

l

The splicing connections between segments are typically made by welding in a locally controlled environment.

Fig. 8: Lattice Tower 12

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Photo 6: Erection of Lens Truss Photo 8: Airport Terminal Inside View 90m span of trusses

7. Conclusion The new Kolkata air terminal is being described as one of the remarkable structures. It has bagged 2nd Best Engineering Marvel for the year 2013 and 2nd Most Impactful Engineering Marvel.

8. Acknowledgements

Airport Authority of India

Architects

RMJM Singapore

Adp.i France

Sikka Associates

Virendra Khanna Associates

Construction Agency

ITD â&#x20AC;&#x201C; ITD Cementation

l

Photo 7: Night view of the completed terminal building

l

l

l

l

l

l

l

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 13


Challenging Concrete Structure with a Blend of Architectural Fair Faced Concrete

Vinay GUPTA Chief Executive Officer, Tandon Consultants Pvt. Ltd New Delhi 110014, India Vinay.Gupta@tcpl.com

Er Gupta, is an active member of various Codes and Standards Committees of BIS and IRC. He has been honored with awards for the best papers titled “Seismic Design and Construction of Radisson Hotel, New Delhi” and “Launching Systems for Segmental Bridges” by IBC and Prestressed Concrete Design Award 2013 by IEI. He has been lecturing as Guest Faculty in NITHE, CRRI, CIDC, ISDA, DPC etc. Er Gupta is the Vice President of ICI

Summary To celebrate 500 years of history of Sikhs and 300 years of establishment of the Khalsa, the mega project ‘Khalsa Heritage Complex’ was launched by the Punjab Government. The project comprises a 150m long pedestrian bridge to connect Complex ‘A’ and Complex ‘C’. While the Complex ‘A’ houses library blocks and a theatre, the Complex ‘C’ mainly houses high-tech exhibits of various types. The special highlights of the project include (i) 26m span prestressed concrete ramps in Heritage Museum building (ii) 20m span RCC roof beams acting as partial catenary in Permanent Exhibit building (iii) 35m span arch bridges incorporating prestressed tie beams (iv) Precast canopy over the pedestrian bridge, (v) Specialized Mechanical Connection between infill brick walls and the adjoining beam-column frame structure for sustainability during high seismic forces (vi) Inception of large volume of architectural fair faced concrete (vii) Preparation of mock ups of all specialized elements, prior to their actual construction. Keywords: Fair Faced Concrete, Mock UP, Arch Bridge, Prestressed Concrete, Triangular Coffer

1. Introduction World famous Museum, Specialist Architect Moshe Safdie & Associates, Bostan, USA were engaged to prepare architectural concept of the 14  Volume 44

Number 1

March 2014

project. In turn, Indian local architects Ashok Dhawan, New Delhi were appointed and Tandon Consultants Pvt. Ltd, New Delhi were retained as sole Structural Consultants for the project. The project basically comprises high tech exhibits to depict the history of Sikhs and Khalsa, in the form of Multi-Media Exhibits, Libraries and Theatres (see fig 1)

Fig.1: A model view of Khalsa Heritage Complex

2. Concept Forms The 60 acre site, situated in front of the main Anandpur Sahib Gurudwara was a barren land comprising a combination of sand hillocks and plains. The architect’s concept inherited a monument emanating from the hillocks. For this purpose, photographs of the preconstruction site were taken from all angles, so that the hillocks, that would have to be flattened during the The Bridge and Structural Engineer


construction could be rebuilt to, as far as possible, the same shapes and forms as they existed before construction. Roofs of the main exhibit buildings have been read as princess’ crown. Stainless steel roof cladding strengthens the concepts, dictated by the architectural demands. An artificial water body, engaging the open areas of the complex adds to nature of Punjab, the land of five rivers. Two sub-complexes are connected by a pedestrian bridge, having the water body, beneath, see fig 2. Extensive use of architectonical fair faced concrete has been made in the project.

spaced columns and beams and allows water to flow underneath the arch, as demanded by architectural needs. The auditorium has an airconditioning system where return air is picked up by the pipes, located below the seats. The roof the auditorium has several interesting features like 25m span roof beams, wherein the beam just above the stage has been provided with 3m deep RCC suspender to suspend the roof at a lower level (see figs 3 and 4)

Fig. 3: General View of Pedestrian Complex ‘A’ Fig. 2: Pedestrian Bridge

3. Project Description The complex has been divided into: (i)

Complex ‘A’, housing a multistoried library complex and a 20m high, 400 seating capacity Auditorium (Theatre).

(ii)

Complex ‘B’, incorporating Pedestrian Bridge, having 4 arch spans of 35m each and a two level cafeteria below the bridge and

(iii) Complex ‘C’, comprising various multistoried buildings to house exhibits. 3.1 Complex ‘A’ Apart from multi-storied library structure and 400 seat capacity theatre, the complex has 35m span arch bridge (entry walk way) along with handicapped ramp structure. Within the library complex, there is 27m span arch bridge that support two upper floors with closely The Bridge and Structural Engineer

Fig.4: Arch Supporting Buildings of Complex ‘A’

3.2 Complex ‘B’ The architectural conception demanded the 4 arch spans (35m each) to be separated from each other by a distance of 6m . Hence, the longitudinal thrust of one arch could not be balanced by the adjoining arch spans. Therefore, each arch span was made independent, using prestressed tie beam, (4 nos. for each arch rib of 7m width) provided below the ground level, see fig 5 for details. Volume 44

Number 1

March 2014  15


Fig. 5: General Arrangement of Pedestrian Arch Bridge

The arch rib was constructed in single phase, using double shuttering (top shutter) for part length of steeper portions. Since, tie rods (for supporting top shutter) were not permitted for architectural reasons, a specially designed arrangement of 7m span trusses at 1.2 spacing to support the 1.2m long pieces of top shutter were used and mobilized in a sequential manner, as the concreting and compaction proceeded, see Fig 6.

7 and 8 for the arrangement of precasting and erection.

Fig. 7: Precast canopy under construction

Fig. 6: Arch Rib under construction using double shuttering

The pedestrian bridge has been provided with a precast canopy, which was precasted and erected from top of the bridge itself. See figs 16

Volume 44

Number 1

March 2014

Fig. 8: Gantry for erection of precast canopy

The Bridge and Structural Engineer


3.3 Complex ‘C’ The Complex ’C’, being large in size, has been sub-divided into two parts, called North Wing and South Wing, see figs 9 and 10. The North Wing comprises a boat shaped building called Heritage Museum, a flower shaped building called Media Exhibit Building and a triangular Entrance Lobby. The South Wing comprises Grand Stair Block, Permanent Exhibit and Ramp Block that houses circular ramps for the handicapped.

the side walls. The ramps comprise 26m span Prestressed Concrete Slabs, post-tensioned using 4S-13 cables provided using flat metallic sheathing.

Fig. 11: Complex ‘C’ –Prestressed Concrete Ramps of Heritage Museum

3.3.2 Media Exhibit Building

Fig. 9: Complex ‘C’ – South Wing

This building has circular coffer structure at intermediate level. The roof is made out of radial concrete beams and slabs. Outer periphery is made out of RCC walls stiffened with buttresses. Invariably, stainless steel roof cladding along with sandwiched P.U insulation has been provided over the RCC roof slab. The structure also incorporates a circular cut out at intermediate level to house special feature incorporating fiber optics, see Fig 12.

Fig. 10: Complex ‘C’ – North Wing

3.3.1 Heritage Museum Building Unique feature of this 25m spans, 20m high building is that it is surrounded by water body, its floor also has water ponded there and its roof also has 200mm deep water. The boat shaped building has 3 levels of U-shaped ramps in the middle (see fig 11) for the visitors movement, who would watch the exhibits displayed on The Bridge and Structural Engineer

Fig. 12: Circular cutout to receive fiber optics feature

3.3.3 Permanent Exhibit Building This 5 storied structure has been provided with 600 deep coffer slab in the lower floors for spans Volume 44

Number 1

March 2014  17


of 20m, in order to have smaller structural depth and allow space for services. The roof has interesting features of 20m span concrete beams, radically arranged, which partly act as catenary structure. Thereby 20m span could be managed in a small structural depth of 700mm, see fig 13. The roof profile follows the surface of a sphere, thereby making the maximum height of the roof little over 20m from the previous level and total maximum height of the building approximately 45m. It may be noticed that triangle shaped roof has become near vertical (over 600 to horizontal) at the ends, wherein top shutter became mandatory to be able to pour and compact the concrete properly.

4. Seismic Analysis and Design Owing to the highly irregular shape of the buildings, expansion joints have been provided at almost all such locations to maintain, as far as possible, regular structure between the successive expansion joints. Space frame has been analyses for seismic forces using Response Spectrum Method with the help of the software STAAD, see fig 15. RCC walls and floor slabs have also been suitably idealized in the grillage model. The project site lies in the highest seismic zone of India i.e. Zone –V. Up to date ductility provisions as per IS: 13920 have been followed. The brick walls have been fastened to the adjoining RCC beams and columns using a specialized anchoring system, detailed incorporating expansion fasteners and MS plates, see Fig 16.

Fig. 13: Radial RCC roof beams

3.3.4 Entrance Lobby The triangular entrance lobby of 25m span has been provided with triangular coffers wherein the reinforcement has been placed at three different levels, so that they are not required to be joggled at the junctions to avoid clashing, see Fig 14.

Fig. 15: Structural model for analysis of permanent exhibit building

Fig. 14: Complex ‘C’ - Entrance Lobby 18  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Fig. 16: Connection of brick wall with RCC members

5. Architecture Fair Faced Concrete Camouflaging of fair faced concrete with fancy architectural finishes creates and excellent blend of structure and traditional architecture. An extensive study was carried out to find ways and means to obtain a concrete colour and surface finish, that would meet the architect’s expectations. A round the world trip was made by the author, along with other concerned, in order to study various methods of concreting including associated quality control measures execised at various project sites. In conclusion, simple things like type of cement used, shuttering material used, tamping of shuttering, form release agent used, time of de-centering, edge protection, temperature etc, all affect the aesthetics and quality of concrete. For the project in question, trials were made with different compositions of grey and white cement to obtain a particular colour. When the concept failed to meet the architect’s demand, it was found, through trials, that Blast Furnance Slag cement (PSC) gave a particular type of light grey colour of concrete, which was acceptably used. PSC als has a distinct advantage of possessing lower heat of hydration, thereby reducing early thermal cracks. After trying steel, marine plywood etc, it was found that Resin Coated Ply imported from Finland produced the most satisfactory surface finish. Even the shuttering joints were planned by the architects, as per the architectural acceptability. Mineral oil based form release agents were found to leave a brownish tinch on concrete surface. So it was decided not to use

The Bridge and Structural Engineer

any form release agent and do a very gradual de-shuttering, in order to prevent spalling of concrete. Time of de-shuttering was laso found to have effect on concrete colour. Therefore, it was ensured that the entire shuttering of an area was de-shuttered at the same time to maintain harmony of colour. Reinforcement has high specific heat, due to which it gets heated much more than the ambient temperatures. This hot reinforcement causes stains on the concrete surface. I order to avoid this problem, the reinforcement was kept under shade during high temperature

6. Mock-Ups Apart from following strict quality control checks, that incorporate material tests and check of site activities, large number of full scale mock ups of specialized items have been prepared and studied in detail, before actual construction of the respective structure. These items include fair faced concrete arch rib, precast concrete canopy of pedestrian bridge, stainless steel roof cladding, dry fixing of curved stone cladding, stainless steel railing etc. refer figs 17 and 18 for some of such mock ups. Purpose of these mock ups is to study the quality of concrete including its colour, efficacy of shuttering system, achievement of proper curved alignment of cladding etc. After a careful study of these mock ups, suggestive improvements, to be incorporated in the final structure, were recorded for suitable action in due course.

Fig. 17: Mockup of precast canopy

Volume 44

Number 1

March 2014  19


7. Conclusions A careful planning and dovetailing of architectural and structural concepts led to an elegant building. Structure had been able to find its rightful place by providing a large quantum of architectural fair faced concrete and not merely hiding it inside false ceiling everywhere.

8. References

Fig. 18: Mockup of curved roof and stainless steel Cladding

20â&#x20AC;&#x192; Volume 44

Number 1

March 2014

-

IS: 456: 2000

-

IS: 1893: 2002

-

IS:14268: 1995

-

IS:875: 1987

-

IS13920: 1993

The Bridge and Structural Engineer


THE GROWING POTENTIAL OF METAL & TENSION STRUCTURES FOR INFRASTRUCTURE DEVELOPMENT IN INDIA

Prem Krishna Former Professor & Head of Civil Engineering Indian Institute of Technology Roorkee, INDIA pk1938@gmail.com Born 1938.Received BE(Civil) and ME(Struct) degrees in 1959 and 1961 respectively from University of Roorkee (now IIT Roorkee), India. Obtained PhD from Imperial College, London. 1964. Served on the faculty of Civil Engineering at the Uny. of Roorkee.1965 – 1998. President, Intnl. Assoc. of Wind Engg.1991-1995. Vice-President, Indian National Academy of Engg.2008-2013. Chairman, Research Council. Central Building Inst., Roorkee. 2010-cont. Active as a Structural Engineering Consultant.

Summary The paper emphasizes the growing potential of metal and tension structures in the context of the infrastructure development, in general, and particularly in India. The growing urbanization leading to the need for constructing tall buildings for residential as well as commercial purposes, for covering large spaces, and, of creating transportation linkages, and, to so expeditiously, will have to depend increasingly on metal as a predominant structural material. The possibility of employing structures based on tension systems – high strength cables and fabric will, and is already providing, a new dimension. The latter are comparatively less known, and therefore the paper brings out briefly the features of these systems. Keywords: Infrastructure, Metal structures, Tension systems, Cables, Membranes, Aerodynamics

1. Introduction Demand for additional infrastructure, in terms of the primary needs of housing, industrial buildings, transportation systems, and the secondary infrastructure for energy, irrigation, space, communication, and so on, is a worldwide The Bridge and Structural Engineer

phenomenon. Whereas the developed world is towards one end of the spectrum in this respect, countries like India are at the other, with rather little achieved so far. The growing population and even more so, their increasing aspirations for a better life, queer the pitch for the developer. Further, for the economy to grow, the industry has to be backed up by excellent connectivity -both transport and communication. Another phenomenon which is to characterize this demand for additional infrastructure, particularly in the developing world, is the growing urbanization-a trend that seems to be irreversible. The urban population of India is likely to grow from 285.3 million in 2001 to 360 million in 2010, 410 million in 2015, 468 million in 2020 and 533 million in 2025, as per the projections based on past trends. Studies project that by 2030, the total urban population of India will be 590 million i.e. 40 per cent of the Indian population would live in urban areas (Mckinsey report). India may require to have an additional Chicago each year for the next 20 years. This would require tall buildings to cater to residential needs and commercial space. The activities of sport, community interaction, and commercial spaces will lend themselves to the construction of large covered spaces. The transportation Volume 44

Number 1

March 2014  21


needs may lead to overhead linkages-often large spans. The country wide transportation network will have large number of bridges too; long spans may often overcome the exigencies of speedy completion. In the overall sense therefore, it is not difficult to envisage that future development in India will have to overcome shortages of space as well as resources -- conventional construction material, financial, and so on. Besides this, there will always be need to race against time and deliver as quickly as possible. All this requires ‘out of the box’ approaches, including the choices for the appropriate structural systems and materials.

system begins to be utilized increasingly by its own dead weight. It is noteworthy that whereas the dead load / live load stress ratio for a small span culvert may be as low as 1/6, for a truly long span suspension bridge, the same ratio for the main cable may be as high as 15. It is therefore imperative to use materials with high strength weight ratios to keep the dead weight to a minimum. Besides this, the increase in dead weight also implies higher foundation costs.it is interesting to note how steel strengths have increased over time, resulting from metallurgical research, necessitated by the above reason. See Fig. 1

In the above context, and also to be more specific to the subject of this paper, one may choose the following three types of structures for further elaboration: 1.

Tall building towers

2.

Large span covered spaces

3.

Bridges – medium to long spans

The generic issues related to the choice of material and structural form are briefly discussed below. Tension systems, which obviously merit a closer look, and are comparatively lesser known, are addressed next.

2. Choice of Material For all the three types of structures being addressed herein, the choice will converge upon metals, in particular steel, with its different variations, and its many attributes, which are, reliability in mechanical behavior; high strengthweight ratio; long life; good speed of construction, adaptability to meet architectural effects; easier reparability, and so on. If for no other reason, but the high strength weight ratio (and getting better with advancement in metallurgy of steels), tall or large span systems – roofs or bridges will be difficult to conceive, without steel being used as the primary structural material. The reason for making this statement is basic. As a structure gets taller or longer in span, the live load to dead load stress ratio becomes smaller. This implies that the structural

22  Volume 44

Number 1

March 2014

Fig. 1: Developments in Cable Steel Strength, vis-à-vis Some Major Suspension Bridges

Materials other than steels have also been developed, with higher strength- weight ratios, such as Carbon Reinforced Plastic Fibre (CRPF). These can be typically twice as strong compared to the high strength steels and have a unit weight which is about a third. However their utilization has yet been rather limited, cost being one reason. Another reason is that unduly reduced mass of the structural elements can give rise to the structure becoming prone to unacceptable instability problems – aerodynamic or otherwise. In the context of a tall building, the column cross sections will become un-manageable with materials of low strength, and useful floor space will be wasted besides increasing the load on the foundations. With the use of high strength steels this problem is overcome effectively. In the case of large covered spaces using arches or space frames, the same logic is applicable. The deployment of suspended/tension systems further enhances this advantage, as brought out in the ensuing section.

The Bridge and Structural Engineer


3. Choice of Structural form For long span bridges/ overbridges or roofs, it is imperative to use higher strength steels, combined with appropriate structural forms such as suspended cables, for efficient utilization of material Fig. 2 shows how the material is utilized almost to full efficiency in a suspended cable subjected to transverse loads, as opposed to a member in flexure. This in a sense establishes the need to use high strength steel cables in medium and long span bridges as well as roof systems. Besides the use of high strength steel cables for creating the roof supporting system for covering large areas, the use of fabrics as roof cladding provides an excellent option for exotic architectural expression.

typical, striking roofs and bridges are shown in Figs 6 to 10. Only the special aspects of tension structure are addressed below very briefly, since the conventional information is well established and known. The special issues include the cable material, analysis, wind loading and erection sequencing.

Issues related to the conventional use of steel are too well known to bear repetition. However those related to tension systems are lesser known and thus briefly brought out.

Fig. 3. Types of Cable Structure

Fig. 2 : Efficiency of the Cable Form

4. Tension systems The development in structural materials is one of the prime factors leading to the revolution that has taken place in cable structures. There has been a marked improvement in the strength. The key factor is the increased strength â&#x20AC;&#x201C; weight ratio. Figures 3 to 5 show the various structural systems which use high strength steel cables combined with steel or concrete structural elements to provide the basic framework. In case of roofs, this framework can be covered with various kinds of cladding, including fabric Examples of some

The Bridge and Structural Engineer

Fig. 4. Forms of Cable Roof Systems

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 23


Fig. 5: Cable Bridge Systems

Fig. 7: A tent type fabric roof supported from cable mesh

(a) A Schematic

Fig. 8: The Rucka – Chuky Cable stayed bridge. Model of a proposed system

(b) Completed structure Fig. 6: The Moses – Mahabida Stadium, Durban

Fig. 9: The first cable stayed Road Bridge in India, Haridwar, 1988

24  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Fig. 10: Akashi Kaikyo Bridge – the longest main span in the world (1991.6 m), Kobe, Japan, 2001

4.1 Cables Wire ropes have been traditionally used as suspension bridge main cables and hangars, in guyed masts and in suspended roofs. These are formed by assembling together a required number of strands and twisting the assembly. (Figure.11). Whereas ropes offer the advantage of flexibility, the size has essentially to be kept limited. A rope has a more open form of construction and has a low extensional modulus. The process of ‘spinning’ cables for a bridge may take up to a year or more. In order to take advantage of factory production, however, it is possible to put together wire bundles (which can be transported on reels from the factory). This would be quicker (1, 2).

Fig. 11: Typical Cable Cross Sections

A crucial feature of any type of cable is the means of attachment to the structure or anchorage. Most factory-made stays are supplied cut to length and with the end fittings already attached. The stay The Bridge and Structural Engineer

manufacturer therefore designs, fits and warrants the cable end attachments. To be effective, the end fitting must withstand the breaking force of the cable without significant yielding and endure dynamic cycling without risk of fatigue failure and without inducing fatigue failure of the cable. For structural cables, the termination generally comprises a conical socket into which the cable end is splayed and cast. The socket is cast steel and the cable end is held into it with a solidified hot molten zinc cast or a resinous compound. Parallel wire stays present special end fitting problems because of greater compactness, higher breaking strengths, lack of inter-wire load transfer capability and larger wire sizes, and, additional safeguards have to be provided. A key issue in dealing with cables is the one concerning their protection from corrosion. In doing so, it is important to keep in view the extent to which the environment is aggressive – is it only the ingress of moisture, or industrial gases or coastal conditions, or a combination thereof! This will determine the extent and levels of protection required. There are several types of protection possible. The first kind is galvanic protection for the wire, which involves different thicknesses of zinc coating. The next is the painting of a strand or a rope. The third is sheathing. An alternative is to provide an outer protective sleeve for the strand, and fill the intervening space with a grout. 4.2 Analysis [3] Basically, cable structures are highly indeterminate non-linear systems, but in the current context, amenable to matrix methods of analysis programmed on high speed digital computers. However, methods of analysis in the pre-computer age were developed keeping in view the limitations of what was possible with hand computation. Thus for suspension bridges there were the Rankine, Elastic and the Deflection theory it is of interest to note, that perhaps to reduce computational effort for early cable stayed bridges, the number of cable stays was chosen to be small, Suspended roofs comprising trusses could be analyzed by using extensions of the deflection theory and networks by the ‘membrane’ theory. Apart from the conventional analysis issues, there is

Volume 44

Number 1

March 2014  25


the aspect of non- linearity which is associated with cable structures and this has to be tackled with numerically iterative procedures of analysis (3, 4). Non-linearity can occur for various causes. (i)

Large displacements – more relevant in guyed masts, ropeways, simply suspended roofs, suspension bridges

(ii)

Cable sag effect – particularly relevant in guyed masts, and stays for cable stayed bridges.

(iii) Axial load–flexure interaction – relevant in guyed masts, cable stayed bridges, suspension bridge towers.

(iv) Nonlinear material behavior – not relevant as long as material is kept within the elastic limit. Another special feature, while analyzing cable assemblies, is the inability of cable elements to take a compressive force. Therefore ‘slackness’ implies elimination of the member. This has to be built into the analysis algorithm. In terms of response to applied loads, cable systems are special, in as much as, non-uniform loading can be important [see fig.12]. Such loading can be caused by superimposed loads, snow or wind. Whereas cable tensions will be critical under maximum uniform load, large deflections are possible under non-uniform loads. In as far as the design of cables is concerned.

Fig. 12: Uniform Load Vs Non-uniform Load: Deflected Form

Cables are designed on the basis of the combinations of the factored loads applicable. The maximum design tension is obtained thus,Usually it is stipulated that the breaking strength of the cable should be at least 2.2 times the maximum tension. 4.3 Wind Effects For these flexible and slender structures wind is perhaps the most important loading. As is known wind is a randomly varying ‘dynamic’ phenomenon. Therefore not only does it evoke an equivalent static response, it causes dynamic effects over and above the same. For smaller structures it is often adequate to evaluate the ‘static’ effects. Thus, for a guyed mast of small height, the wind forces can be worked out from force coefficients for towers and cables given in codes of practice or relevant literature. For taller towers though a ‘gust’ analysis has to be carried out 4.3.1 Roofs In roofs unless one is dealing with a very large span, dynamic effects may only be moderate.

26  Volume 44

Number 1

March 2014

The important issue is that, non-uniform loading causes larger deflections in cable roofs and arising out of the geometrical shape, these roofs experience wind pressures which are essentially non-uniform. Furthermore, information about wind loads on curved roofs (which typically cable roofs are) is generally not codified but a limited amount of information is given in specialist literature [5]. Wind tunnel testing may be required for cases not covered. 4.3.2 Cable Bridges For cable bridges [2,6] wind effects both static and dynamic are important. Failure of shorter bridges in high wind storms is not unknown. Also there are examples of a number of early suspension bridges having got damaged or failed during wind storms - the failure of the Tacoma Narrows Bridge in 1940 under moderate wind is the most striking example of this type. It is noteworthy that the site peculiarities can often manifest themselves into a dramatic influence on the aerodynamic effect on such bridges. Attention must be given to this aspect. Perhaps the best

The Bridge and Structural Engineer


course is to study these situations through wind tunnel testing, as was done, for example, for the Tatara Cable Stayed Bridge in Japan.

deck at discrete intervals and the movement of these will oppose the motion of the deck due to aerodynamic forces [7].

The static response of the bridge can be best seen in terms of the force coefficients, representing drag, lift and pitching moment respectively, which are to a great extent dependent upon the shape of the deck as well as the angle of incidence of wind (measured in the vertical plane). The dynamic behaviour of the bridge under the action of wind loads is dependent upon the flow; particularly in terms of the turbulence characteristics, and the structural as well as aerodynamic characteristics - the mass, stiffness, frequency, geometrical shape and damping. These characteristics are often related to the bridge form and span, the various forms of aerodynamic response can be described as - buffeting, vortex induced oscillations, and, self-excited oscillations such as galloping, or, flutter. There is a close link between bridge aerodynamics and the Cable Bridge form. It is best, therefore, to proceed by studying the problem in terms of the three major components in a cable bridge superstructure the deck, towers and cables

Towers. For long bridges, towers may rise upto 200m plus above the foundation level. This is almost as high as the Eiffel tower. These towers therefore have similar problems of dynamic response to wind as tall buildings or other tall structures. The aerodynamic behaviour of these towers is significant for their own safety as also because it influences the behaviour of the bridge as a whole. It is important also to ensure the aerodynamic stability of bridge towers during the erection stage before the cables are erected. The tower legs experience both along-winds as well as across wind oscillations for which the design has to cater. The cross sectional shape should be such as to minimise wind-induced oscillations Temporary or permanent damping devices can also be introduced.

The Deck.This is the most important component of a bridge from the standpoint of the aerodynamic behaviour of a cable bridge, and is therefore the one most investigated. Initially cable bridges used stiffening girders or trusses along with a concrete or a steel deck. This trend continued until the collapse of the Tacoma Narrows suspension bridge mentioned earlier. Following this failure, the idea of using box girder decks took root to meet the requirements of adequate flexural as well as torsional stiffness, as well as to minimize wind loading. One of the major design concerns thereafter has been to choose a deck and stiffening system to raise the critical wind speed for the initiation of flutter above the design wind speed, while also ensuring adequate stiffness. It is possible to use fairings on the edges of the deck along parts of its length, in order to reduce its oscillatory motion. It is possible too that the use of passive controls such as the use of control surfaces or ‘wings’, or, pendulums can be of advantage in suppressing deck oscillations. The idea is to provide controls on both edges of the The Bridge and Structural Engineer

Cables. For suspension bridges, cables are quite massive, and do not generally present a problem of aerodynamic instability. The hangers often experience ‘singing’ which is an across-wind vibration of the hanger. The same kind of vibration is possible in cable stays. As stays become longer, the problem of rain-wind induced vibrations also becomes a possibility. Furthermore, hangers and stays may often be provided in pairs, or may even consist of 4 small size ropes or strands. In such cases ‘wake’ induced across-wind oscillations may occur. To overcome these problems, provision of auxiliary cables for long stays, use of damping devices to control ‘singing’ and use of surface features to take care of ‘rain - wind’ and other oscillation problems are used.

5. Importance of Erection Sequencing As may have become evident, cable structures are often large and complex structures. While designing these for safety during their service life is imperative, equally important is to draw up a suitable construction sequence and to examine the various elements involved for their safety during erection. It is noteworthy that lack of careful planning during erection can lead to otherwise safe structural components getting overstressed. Volume 44

Number 1

March 2014  27


Acknowledgement

4.

Buchholdt, H.A., “An Introduction to Cable Roof Structures”, II Ed., Thomas Telford, 1999.

5.

Krishna, P., “Wind Effects on Curved Roofs”, Proceedings of 2nd Asia Pacific Symposium on Wind Engineering, Beijing, China, 1989.

6.

Krishna, P., “Dynamic Wind Effects on Bridges”, Proceedings of the National Symposium on Advances in Structural Dynamics and Design, SERC Madras, Chennai, India, Jan. 2001.

7.

Fujino, Y., “New Control Method for Flutter Suppression of Long Span Bridges”, Proc. of International Seminar on Long Span Bridges and Aerodynamics, T. Miyata et. al. (Eds.), Springer, 1999.

The author has drawn upon his earlier writings and publications, in preparing this paper. Preparation of this script by Megha Sharma is thankfully acknowledged.

References 1.

Walton, J.M., “Developments in Steel Cables”, Journal of Constructional Steel Research, Elsevier Applied Science, Vol.39, 1 August 1996.

2.

Krishna, P., “Tension Roofs and Bridges”, Journal of Constructional Steel Research 57(2001) 1123-1140, Published by Elsevier Sciences Ltd.

3.

Krishna, P.and Godbole, P.N. “Cable Suspended Roofs”,II Ed. McGraw-Hill Education, India, 2013

28  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


case study of grand arch - the ireo housing

Dr. Vinod JAIN Managing Director Vintech Consultants New Delhi, India vjain@vintechconsultants.com

Dr. Vinod Jain, Born 1963, received his civil engineering degree from Thapar University, Punjab. He did his M.Tech & Ph.D (Structures) from IIT Delhi. He has received numerous awards from various renowned Organizations for his outstanding performance and contribution in the field of Structural Design.

Summary Grand Arch is a landmark housing development by IREO Group in Gurgaon (sector 58) that breaks the mold, undoing negative stereotypes and serving as remarkable works of architecture and structural designing in their own right. Spread over almost 20 acres, Grand Arch is truly created to achieve the next level of living. This multistory residential housing comprises of various clusters of High rise Towers and Midrise buildings surrounded by extended basement as planned by Architects. High rise Towers consist of Ground+2Basement+26 to 28 floors, Midrise Towers consist of Ground+2Basement+7 floors. Double basement houses various services and serves as the parking for the residents. The tower that stands out from the rest and which is the soul of Grand Arch is the Arch Tower.

separate towers which go up to 20th floor level and are mirror images of each other. At the 20th floor level, these two wings get connected by a bridge and the bridge supports two storeys above it which are penthouses. These penthouses are the unprecedented marvels of luxury and superior living. They have a wonderful feat of engineering and are an emblem of the new and dynamic real estate in whole of National Capital Region.

Keywords: High rise tower, box girder, Mivan Shuttering, bearing stress, cross diaphragms, camber, warping stress, storey drift, torsion, free body diagram.

1. Introduction of Arch Tower

Fig. 1: Key Plan of Grand Arch.

The Arch tower comprises of two different wings i.e. east wing and west wing. These are two

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 29


WEST WING

ARCH TOWER

EAST WING

Fig. 2: Project view

2.

Consultants

Client – IREO Group Structural Consultant – Vintech Consultants, New Delhi Architect for Concept Stage – Sorg & Associates, Washington DC Executive Architect – Spazzio Design Architecture Pvt. Ltd., New Delhi Proof Consultants – Indian Institute of Technology, Chennai (Prof. Devdas Menon) Contractor – Larsen & Toubro

3. Special Features 1.

There is a lower transfer level happening at the 2nd floor to facilitate the lobby at the Ground Floor Level. This has been done to make the lobby and reception more spacious and impressive.

30  Volume 44

Number 1

March 2014

Fig. 3: Ground Level Plan (West Wing)

2.

The floor plans of East and west wing are quite interesting in their profile. They are actually 3 separate blocks going up to 20th floor and getting connected to the core by just a corridor. The floor plate of the corridor is designed for the moments induced due to the deflections of the different tower. Architecturally also, these corridors present a wonderful site for inhabitants of the building. The Bridge and Structural Engineer


5. Upper Level Transfer

Fig. 4: Typical Level Plan (West Wing)

3.

There is another upper level transfer happening at the 20th floor level. This transfer is happening to support the common penthouses of two separate towers i.e. east wing and west wing. Itâ&#x20AC;&#x2122;s like a bridge connecting two different towers. Best part is that penthouses are built on this bridge.

Fig. 5: Transfer Level Plan (West Wing)

4. Salient Features of Arch Tower Mivan shuttering system has been adopted for this building with shear walls as load bearing walls and minimum beams. Flat slab has been provided on all the floors. Ductile shear walls with Ordinary Moment Resisting Frame have been adopted as the lateral load resisting system for this building. Building has been designed for zone 4 of earthquake as Gurgaon falls in zone 4 category. Raft foundation has been adopted. Dynamic Analysis of the building has been done. Building height being 90 m from the base, wind loading has been applied using the gust factor method. The Bridge and Structural Engineer

The upper level transfer is occurring at the 20th floor level. This floor is a service floor level and accommodates the transfer girder and the various services. The depth of the transfer girders is 3.4 m i.e. equivalent to one storey height. We have basically provided a box girder in a span of 33 m. The box consists of 4 transfer girders of 33 m length. 3 girders are 600 mm wide and peripheral girder of box is 450 mm wide. Two diaphragm girders of length 10 m and width 600 mm have been provided at the two ends of the box. 3 cross diaphragms of 275 mm width have been provided at every 1/4th of the span. Bearing Stress concentration in the shear walls supporting the transfer girders immediately at the bottom of the girders at the junction of girder and supporting shear wall was checked and brought under the permissible stress levels as specified by IS 456.As per code permissible bearing stress shall be 0.45 fck. It is required to control the stresses to avoid crushing of concrete at interface of Transfer Girder and shear walls. This was one of the major deciding criteria in fixing the sizes of shear walls supporting the girder. For extra safety, the shear walls just below the transfer girder have been flared. The introduction of 3 cross diaphragms at every 1/4th of the span ensured a smooth lateral load transfer path and reduced the stress concentration in the shear walls supporting the girder. By providing 4 girders, the structural system will act as continuous in minor direction. Also, the sizes of the girders reduce when we provide 4 girders as it is a more stable system and the no. of members carrying the load increase. The cross diaphragms prevent the warping stresses induced due to the differential deflection of the 4 transfer girders. The thickness of the slab connecting the transfer girders was taken as 275 mm. This slab also forms a part of lateral load resisting system in box girder. A camber of 40 mm has been provided in all 4 transfer girders to help in controlling the elastic deflections. Small sized openings have been provided in the cross diaphragms to allow the passage for various services. Various stub columns of the pent house levels are erecting from these girders. The design acceleration spectrum Volume 44

Number 1

March 2014â&#x20AC;&#x192; 31


Fig. 6: Elevation of Box Girder

Fig. 7: Reinforcement in Transfer Girder (Detail A)

of the stub columns has been taken as 2/3rd of the design horizontal acceleration spectrum. Storey drifts were checked and framings were worked out in such a manner that all the storey drifts were in permissible limits and there was no torsional irregularity in building. There were two box girders exactly mirror images of each other connecting the east and west wing at the two ends. The behavior of the building was checked in different modes and was found to be ok. The symmetry of the building and the transfer girder greatly helped with the analysis. Building was also checked for soft storey and was found to be ok.

Fig. 8: Reinforcement in Peripheral Transfer Girder (Detail B)

6. Analysis of Arch Tower

Fig. 9: ETABS Model of Arch. Tower 32â&#x20AC;&#x192; Volume 44

Number 1

March 2014

For the analysis of the building Finite element software ETABS was used. To doubly check the results we modeled the building in STAAD Pro. also and compared the results of both the models. Various manual calculations were performed to check the behavior and the results of the transfer girders and the shear walls supporting the transfer girder. Results were also cross checked by modeling and analyzing the free body diagrams of various elements in ETABS and STAAD Pro. The flat slab analysis was done by exporting the slab from ETABS to SAFE. Analysis of raft foundation was also carried out from the SAFE software. The Bridge and Structural Engineer


Fig. 10: Transfer Level Plan in ETABS Model

Fig. 11: Box Girder

7. Construction Bridge

Sequence

for

the

Two ISMC 400 were provided at the periphery of east wing and west wing where a truss was

The Bridge and Structural Engineer

supported at the 19th floor level. At the 21st floor, diversion pulley were installed which were used to hang the truss. This truss acted as a shuttering platform with the help of which the upper floor levels were casted. Construction of the bridge Volume 44

Number 1

March 2014â&#x20AC;&#x192; 33


In the 3rd stage the top slab of girder shall be casted.

i.e. the girder level was carried out in 3 different stages-

3)

1)

Longitudinal girders were casted first as I sections along with central cross walls (diaphragm walls).

2)

Bottom slab of girder was casted in 2nd stage after the longitudinal girder has attained 28 days strength.

This was followed by the casting of the upper structure with the load of the upper structure taken by the box girder. All the allowances in girder stresses were checked at different stages. The detailing of the transfer girder has been done in a fashion to facilitate construction.

Fig. 12: Construction Photo 01

34â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Fig. 13: Construction Photo 2

Fig. 14: Arch Tower Completed

8. Conclusion When this project started 4 to 5 years back, it was very challenging. Firstly, it was thought that at the top where transfer girder was happening, expansion joint will be provided. This way transfer girder would have been sliding at the top of one wing and fixed with other wing. But with this approach, it was difficult to control the building deflections at the top. The behavior of whole building was getting uncertain. So, the approach that has been explained in this case study was adopted. This theory and the striking symmetry in the building helped a lot in achieving an apt The Bridge and Structural Engineer

and consistent behavior in the building. But to achieve this lot of research and hard work was done. The building was analyzed in ETABS and STAAD Pro. The grillage of the building to study the independent behaviors of various elements was also formed. Various manual calculations were done. This whole task in itself was quite interesting and thrilling at the same time. In the end, the hard work paid very well. The building design turned out to be quite satisfactory and as per everyone’s expectations. The construction of the building was completed in the year 2013. Today it’s one of the finest places in Gurgaon to live in. Volume 44

Number 1

March 2014  35


ANALYSIS APPROACH TO OBTAIN EUDL FIRE TENDER LOADING ON NON-TOWER AREA OF HIGH RISE GROUP HOUSING PROJECTS

Er.(Dr) Abhay Gupta Director Skeleton Consultants Pvt. Ltd. ESCOM Consultants Pvt. Ltd. Noida, India abhay.gupta@skeleton.in abhay@escom.in abhaygupta62@rediffmail.com

Keywords: Fire tender, High Rise, Non-tower, EUDL,

1. Introduction This paper enlists and discusses some issues related to analysis & design of non-tower basement slabs at ground level supporting fire tender vehicle loads using equivalent UDL consideration in High Rise Group Housing projects.

2. Discussion In the recent scenario many group housing projects are being developed in India. These group housing projects have high rise towers with large basements connected with non-tower area at ground floor level. In case of fire these ground floor slabs are subjected to movement of fire tender. Therefore, these slabs are designed for fire tender loadings in the similar way as in bridges and needs in depth analysis. Among all the structural consultants there are difference of opinions on the intensity of loading to be considered for design of non-tower slabs/ beams/columns and foundations. There is no specific step by step approach given in literature to find out this load intensity. Common practice is to consider an approximate equivalent UDL in design.Our design team has made some efforts to methodically document &improve this, discussed with several other consultants and implemented in many projects as per below concept. 36â&#x20AC;&#x192; Volume 44

Number 1

March 2014

Abhay Gupta, born 1962, received his Ph.D. in Structural Engineering from IIT Roorkee. A dynamic, multi-dimensional Civil & Structural Engineer with vast experience in the areas of RC & Steel Designing, Construction Management, Teaching and Research, and Team Building; imparting Leadership to a group of people in pursuit of achieving individual and organizational Goals.

Filling on non-tower slab is an additional criterion, as the load gets distributed due to this filling. There is another issue, regarding the capacity of fire tender to be used in design. While designing the slab of non-tower area according to local authority norms different capacity of fire tenders are considered which may be 45MT, 60MT etc. However load data for60MT fire tender is not available, designers tend to extrapolate the 45MT data which is not correct as the number of wheels and axles in actual vehicle might change. In addition to this fire tender route is also sometimes not defined in the beginning of the project and complete non-tower area slabs are designed for fire tender loading. RC Retaining walls also need to be designed for fire tender loads either received directly from the nontower slabs or as surcharge if the fire tender is moving outside the Retaining wall. If the route of fire tender is predefined, significant economy can be achieved. In some cases if fire tender is considered on non-tower area only, there is no need to design the retaining wall for surcharge, instead fire tender load shall be transferred as axial loads and design can be optimized. If route of firetender is finalized then only those slab panelscan be designed for heavy loads. Fire tender load consideration along with earthquake force is also a concern. In general these loads are not considered simultaneously because of non probability of both occurring simultaneously. The Bridge and Structural Engineer


3. Analysis In the design, there are two main criteria.One is for static condition, i.e., based on jack position, number of jacks & diameter of jack. The other is for moving condition, i.e.,based on wheel load as moving load, number of axles & number of wheels. In the first criteria the slab is designed basically for two positions. One is by placing jack at the edge of slab and second is by placing the jack at the centre of slab and maximum intensity is worked out. In the second criteria, i.e., by moving load analysis, there may be so many locations based on slab panel size. Rigorous analysis is done using STAAD or other software by moving load method and the most critical location for maximum moments/shear is calculated. For

this moment/shear,equivalent load intensity is worked out by another STAAD analysis. Higher intensity of above two methods is used in design of the members which are directly affected by this load, i.e., slab & beam. Columns and foundations receive the load through the slab and beam, hence are designed for a reduced EUDL intensity, which is calculated by considering total fire tender load distributed on complete panel area and for this intensity columns & foundations are designed. In many projects these analyses are done, however case study of one of our projects is enclosed herewith indicating equivalent UDL for a 45MT fire tender. The calculations presented will make the procedure much clear and is selfexplanatory.

4. Summary of Results

Sr. No.

1. 2. 3. 4.

Structural Element

Column Foundation Beam Slab

SUMMARY OF EUDL for 45 T FIRE TENDER Based on Based on Based on Jack Wheel load with Moving Wheel Position soil filling Load (kN/m^2) (kN/m^2) (kN/m^2) 6.89 6.89 14.43 15 19.5 14.43 15 19.5

Design EUDL (kN/m^2)

6.89 6.89 19.5 19.5

5. Conclusion

5.

In the overall cost economics of high rise group housing developments, the design of non-tower slab supporting the fire tenders plays a very vital role. Also, it poses a safety hazard, if not properly designed. Several issues related with fire tender design & economics are:

However, the rational design needs rational estimation of loaded elements and the EUDL intensity.

1.

Fire tender route to decide the elements affected

2.

Capacity of fire tender to be used based on NBC-2005 & fire authority rules

3.

Wheel load data of Fire tender vehicle, i.e.,Number of axles, number of wheels, spacing, wheel load etc.

4.

Earth filling over the non-tower slabs for landscape etc.

The Bridge and Structural Engineer

Slab panel size and column grid size.

The analysis presented herein shows that load intensity for direct contact elements like Slab & Beams are much higher and the same for columns and foundations which receive through slabs and beams are much less. Earthquake and fire tender loading need not be combined owing to very less probability of simultaneous occurrence. The EUDL intensity for design of elements significantly changes with the thickness of soil cover available which distributes Jack load or wheel load to a larger area and hence should be calculated separately for each project. Volume 44

Number 1

March 2014â&#x20AC;&#x192; 37


The panel size of slab also is important and need to be properly accounted for in EUDL calculation. In brief, philosophy of a random EUDL for all elements irrespective of column grid and slab panel size, soil cover etc. needs to be replaced by project specific calculations and should be suitably accounted for in the analysis and design.

6. Acknowledgements Author gratefully acknowledges the contribution of his design team members, Er. Vandana Verma, Er. Nitesh Agrawal and others in preparing calculations presented herein. Also, time to time discussions with several design consultants during the process of proof checking on various

projects are acknowledged. Thanks are also due to ING-IABSE for inviting this paper from me and providing opportunity to interact. All the readers are requested to send their views on the contents and opinion expressed herein.

7. References 1.

IS 456:2000 – Plain and Reinforced Concrete – Code of Practice

2.

Reinforced Concrete Designer’s Handbook – Charles E. Reynolds and James C. Steedman

3.

IRC6

Attached are following figures and tables in support of the case study presented.

Fig. 1: Layout of Towers & Non-Tower at Ground floor level

Fig. 2: 45MT Fire tender Wheels and Jack positions 38  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Fig. 3: Fire tender Standing & Moving condition load positions

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 39


Table 1: Fire Tender Load Calculations for Jack Loading in Standing position on Column & Beam

40

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014

41


Table 2: Fire Tender Load Calculations Based on Wheel Load & Soil Filling

42

Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Salient Planning, Design & Construction Features of Newly Constructed Multi-Level Underground Automatic Car park for 800 Cars at Kamlanagar, Delhi

Achyut Ghosh Director- Simpark Infrastructure Pvt Ltd, Kolkata Ghosh.achyut@gmail.com

Alok Bhowmick Managing Director, B&S Engineering Consultants Pvt. Ltd., Delhi bsec.ab@gmail.com

Shirish Mulmuley Dy General ManagerBusiness Development, SMS Infrastructure Ltd, Nagpur shirish.mulmuley@smsl.co.in

Born 1941, Engineering Graduate in Mechanical Engineering from Calcutta University, Bengal Engineering College, Sibpore, West Bengal, Ex-director Metcogroup of Companies, Designer of various equipment like Pile Driving Machine, Railway Traverser, Transfer Cars, Designer of Bridge Bearings & Expansion Joints, Ex-member IRC Bridges Committee, Member IRC Bearing Committee (B6) & Steel Structure Committee (B5), Exmember ACI Bearing Committee 554, Visiting Professor IITâ&#x20AC;&#x2122;s & other colleges in India and abroad

Mr. Alok Bhowmick, born 1959, graduated in Civil Engineering from Delhi University in 1981 and did his post graduation from IIT, Delhi in 1992. Mr Bhowmick has made significant contributions in the field of structural engineering both within and outside his organization by sharing his expertise and experience. He is an active member of several technical committees of Indian Roads Congress. He is a fellow member of governing council of Indian Association of Structural Engineers.

Mr Shrish Mulmuley, born 1972 did his graduation from Nagpur University in Mechanical Engineering. He has professional Experience of about 16 years in Business Development and Project Management. He is associated with this Automated Multilevel Car Parking Project since its conception as Manager Business Development and then Project Coordinator.

Summary Salient planning, design and construction features of one of the largest PPP based fully Automated Multi level Underground Car Parking, circular in shape with 8 floors below the ground and 3 floors above ground, constructed for North Delhi Municipal Corporation of Delhi (NMC) is presented in this paper. This is one of the rare project with several unique technical features, requiring creative and innovative solutions. The available land area for parking was only 3195 m2, in circular shape. The requirement was to accommodate 800 cars for parking, with maximum allowable height of 15m above ground. This could be achieved with the proposal of The Bridge and Structural Engineer

multi-level automated system with retrieval time of only 3 minutes. Keywords: Diaphragm Walls, Pile Foundation, Water proofing, Dolly

1. Introduction 1.1 Commercial Narratives Kamlanagar is a large, thickly populated and busy market area with various outlets of national and multinational brands around, with very high rate of increase in vehicular traffic. Considering the lack of space available for parking in this area, it was considered an ideal location to provide a multilevel car parking to meet the present and Volume 44

Number 1

March 2014â&#x20AC;&#x192; 43


future needs. The Kamlanagar car park is Indiaâ&#x20AC;&#x2122;s largest PPP based fully Automated Multi level Underground Car Parking project with 8 floors below the ground and 3 floors above ground, constructed for North Delhi Municipal Corporation of Delhi (NMC). The upper 3 floors above ground will be leased out for commercial use. Presently the entry level lobby along with 6 parking floors (level 2 to level 7) will be used. The 8th level is for future provision. The structure is built in a thickly populated area, inside a circular park, which was enclosed by shops and commercial area on all sides, in the middle of Kamlanagar Market. The park is converted to an underground automatic car park. Photo P1 shows the traffic scenario in the area prior to construction of this structure. Fig.01 shows the General Arrangement of the structure. Photo P2 shows the location of the structure in Google Map. The various agencies associated with this project and stake holders for this project are : 1.

Owners :

North Delhi Corporation Delhi

Municipal (NDMC),

2.

Consultant to Owners :

SimPark Infrastructure Pvt Ltd (SimPark), Kolkata

3.

Co-Consultant to SimPark for Checking of the Civil Designs :

B&S Engineering Consultants Pvt Ltd (BSEC), Noida

4.

Constructors & Concessionaires:

SMS Infrastructures Ltd, Nagpur

5.

Technology Partner:

Proviron technology BV Switzerland

6.

Engineers, Architects & Project

VSK Associates, Delhi

The construction for this project commenced on March 2010 & completed in 3 years. The project cost is about 160 Crores. Salient milestones for the project are as under : a. Substitution Agreement

February 2010

b. Effective date of start of concession period

February 2010

c. Date of Commencement of Work

March 2010

d. Stipulated Date of Completion

March 2012

e. Actual Date of Completion

September 2013

f.

50 years

Concession Period

Technical and feasibility study and preparation of tender papers was done by SimPark, Kolkata. Engineers from SimPark and professors of IIT, Delhi attended the bid presentation and also evaluation of bids. In the JV between SMS Infrastructures Ltd, Nagpur and Proviron Technology BV, Switzerland, the lead partner is SMS Infrastructures Ltd. Technology is provided Proviron Tecnology BV while the construction is done by SMS Infrastructure Ltd.

Photo P1 : Traffic Congestion at Kamlanagar Prior to Construction of Parking Structure

Fig. 1: Artists Impression of the Parking Structure

44â&#x20AC;&#x192; Volume 44

The Bridge and Structural Engineer

Number 1

March 2014


at any typical basement floor level 2 to level 7. There will be two (2) transfer cars in each track. There will be two (2) such tracks in each floor; i.e. there are four (4) transfer cars in each floor. There are six (6) parking floors. Altogether there are twenty four (24) transfer cars. Each transfer car has one (1) dolly. Each of six (6) lifts has one (1) dolly. Altogether there are thirty (30) dollys.

Photo P2: Location of the Parking Structure in Google Map â&#x20AC;&#x201C; Influence Area Shaded

Proviron has supplied and operating such car parking system in various countries of Europe, South East Asia and Middle East. The job was awarded on BOT basis. The concessionaire, SMS JV, will run the system for the period of concession (i.e. 50 years) including collection of parking fees and leasing of the commercial space (3 floors above the ground).

Fig. 02: Plan at Ground Level

1.2 General Description of the Project The structure is circular in shape with an outer diameter of 63m. The design capacity of the facility is 800 cars. The cars are to be parked and retrieved by the automatic car parking system using levels 2 to 7, ie in 6 levels @ of 138 cars per level. The scooters will be parked manually at level 1 (entry lobby), which is also the receiving and delivery level for the cars. 294 nr of cars can be parked in an hour using 6 elevators and 30 nr robotic dollys. 6 elevators are provided in a single block. In the level 1, one side of the elevator block will be used for receiving the cars, whilst the other side will be used for delivery. Each elevator will have a receiving chamber and a delivery chamber on the opposite side on level 1. Each elevator will have one parking stall at each of the two sides on every parking floor. These parking stalls can be used as delivery and/or receiving purposes. FIG.02 shows the plan at ground (manoeuvring) level of the structure. FIG.03 shows the plan The Bridge and Structural Engineer

Fig. 03: Plan at any Typical Parking Level below Ground

A dolly can travel along horizontal X-axis only. It can travel on the parking floor and enter below a car parked on the parking stall. The withdrawn four (4) comb like fingers are extended outside the dolly to a position below the four (4) wheels. The comb like finger are vertically raised, the dolly travels in the X-axis only carrying the car Volume 44

Number 1

March 2014â&#x20AC;&#x192; 45


along. The dolly can bring the car to its position on the elevator/ the transfer car/ another parking stall and can rest the car there. The car resting process is just the reverse of car lifting process. Each transfer car can travel along horizontal Y-axis only in its designated track in each floor. It can travel with the dolly loaded with a car or in unloaded condition. The dolly is connected with the transfer car by an umbilical electrical cord through cable reeling drums with power and control cables. As such the transfer car can only travel with the dolly withdrawn on it. Each lift can travel along vertical Z-axis only in its designated well crossing the floors. It can travel with the dolly loaded with a car or in unloaded condition. The dolly is connected with the lift by an umbilical electrical cord through cable reeling drums with power and control cables. As such the lift can only travel with the dolly withdrawn on it. There are two (2) sloping curved entry ramps to the entry level from the road level to entry lobby for the delivery of the car to the car park. Similarly there are two (2) sloping curved exit ramps from the exit lobby to the road level, for taking the delivery of the car from the car park to the outside road.

In several countries, the entire operation is automated. However considering the general technological knowledge base and reading ability even of sign languages of drivers in our country, human controls are introduced at the entry / exit level. However in between Car In & Car Out ie After Car In and Before Car Out, all operations are automatic and controlled by a dedicated programme operating 24/7 hours. These operations does not require any human interference except during maintenance and initial setting. The detailed procedure is as described below : 2.1.1 Car In The car is driven along the entry ramp. The driver collects the smart card from a human dispenser inside a cubicle at the end of the ramp at the entry lobby. He aligns the car in front of any of the six (6) receiving chambers, for car receiving, which is empty. He touches the smart card to the touch plate of the entry bar gate. The gate opens. He drives the car inside the receiving chamber and parks the car on the stalls. This is a seamless operation. He locks the car and goes out using the designated stairs or the passenger lift. 2.1.2 Car Out

1.3 Used Area Total area of the plot

3 192.3 m2

Permissible ground coverage

50% of plot area = 1 596.1 m2

Permissible FAR

100

Total permissible covered area

3 192.3 m2

Covered area on ground floor

50%

Covered area on first floor

= 40%

Covered area on second floor

= 10%

The driver enters the exit lobby using the designated stairs or the passenger lift. He shows the smart card to one of the human operators inside cubicles at the end of the ramp at the exit lobby. The operator touches the smart card to the card reader. The parking fees in rupees are displayed in the VDU. On receipt of the payment the number of the delivery chamber is displayed. The driver goes inside the designated delivery chamber, unlocks the car and goes out using exit ramp.

Total

= 3192.3 m2

2.1.3 After Car In

Parking area including entry = 3 192.3 x 8 = level area 25 538.4 m2

2. Salient Technical and Functional Features of the Building 2.1 Car In / Out Operation Car in and out operations are fully automated without the requirement of any human operator. 46â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The driver locks the car parked on the stalls inside the receiving chamber. The lift corresponding to the receiving chamber, will arrive if not already there. If not already empty, the lift will deliver the car to the delivery chamber on the opposite side. The dolly on the lift will collect the car just parked on the stalls inside the receiving chamber, and will withdraw inside the lift. The lift carrying the car mounted on the dolly will go down to the The Bridge and Structural Engineer


floor as dictated by the programme. The lift will deliver the car to the receiving/ delivery stalls juxtapose to the lift, on the floor on which it has stopped, as dictated by the programme. The lift becomes free for the next operation. Meanwhile the transfer car on the track on that side of the lift has travelled along the Y-axis and aligned itself along the centre line along the Xaxis of the receiving stalls. The dolly on the transfer car will collect the car just parked on the receiving stalls and will withdraw on the transfer car. The transfer car carrying the dolly with the car mounted on it will travel on its track and will align itself against an empty parking stall. The dolly with the car mounted on it will deliver the car on a parking stall and the empty dolly will withdraw itself on the transfer car. The transfer car becomes free for the next operation.

parking on the same X-axis. When a transfer car has the order to extract the deep parked car with a car parked in front, it takes the front car and parks the same in a empty slot, thereby freeing the deep parked car for delivery. Whenever there is double parking in the system, some free empty slots are operational requirement. More the number of empty slots in the planning, the faster is the overall through put speed.

2.1.4 Before Car Out

There is 100% power back-up using two number diesel generator set. The back-up diesel generator set will come into operation seamlessly, in the event of power failure.

The operator touches the smart card, received from the driver to the card reader. On receipt of payment he will push the car out button. The programme has stored knowledge of the address (floor nr & stall nr) of the parking stall, on which the car is parked. The programme calculates the shortest time route for the corresponding transfer car to the nearest free lift. The transfer car on the track on that side of the lift will travel along the Y-axis and aligned itself along the centre line along the Xaxis of the stall on which the designated car is parked. The dolly from the transfer car will collect the car parked on the stall and will withdraw on the transfer car. The transfer car carrying the dolly with the car mounted on it will travel on its track and will align itself against the X-axis of the designated lift. The dolly with the car mounted on it will deliver the car on a delivery stall against the X-axis of the designated lift. The empty dolly will withdraw itself on the transfer car. The transfer car becomes free for the next operation. The dolly on the lift will collect the car just parked on the delivery stall, and will withdraw inside the lift. The lift carrying the car mounted on the dolly will go up to the exit lobby. The lift will deliver the car to the delivery stalls juxtapose to the lift, on the exit lobby. The empty dolly will withdraw itself on the lift. The lift becomes free for the next operation. As can be seen at most of the areas there are double car The Bridge and Structural Engineer

2.2 Electrical System 2.2.1 Power & Voltage The operating system voltage is 415 ± 6% V 3 ph 50 ± 3% Hz. Required power is 600 kW. Supply system is 33 kVA high tensile. There is a step down power transformer within the premises. 2.2.2 Back-up

2.3 Electronics & Communications System 2.3.1 Programme The whole purpose of the dedicated programme is to reduce the cycle time all the time 24/7 hours. The programme contains the logic for choosing the particular transfer car and the particular lift depending on their loading condition during both car in and out stages, the logic being reducing the cycle time to the extent possible. The choice of the floor is an important factor in reducing the cycle time. It is general fact that the less loaded a floor is, the faster is the through put. The programme takes care of the optimum cycle time considering the additional lift travel to a lower floor versus faster dispensation in a lightly loaded upper floor. The programme The dedicated programme was imported. The dedicated programme is loaded in a microprocessor placed inside a control box. The microprocessor acts through PLC’s. The incomings of the PLC’s are signals from various transducers and limit switches. The outgoings of the PLC’s are sent to the controllers of various electrical motors as signal for start, stop, acceleration and deceleration etc. Volume 44

Number 1

March 2014  47


2.3.2 Stalls Each of the 800 stalls and the service stalls have a reflector erected on the right side. The dolly has a laser beam projector cum receiver on its right side. During the travel towards a stall the location is decided by a digital counter set at two measured values for the front and deep parking locations. 2.3.3 Dolly The dolly is connected to its parent equipment ie either the transfer car or the lift by two separate cables for power and control. The cable reeling drums are mounted on either the transfer car or the lift as the case. There are limit switches, a laser beam projector cum receiver mounted on the dolly. There are two junction boxes but no electrical control gear. 2.3.4 Transfer car The transfer car carries two cable reeling drums for the dolly. The supply of control and power to the transfer car are effected through drag chain for carrying the cables. The cables are connected to the joint box mounted on the wall at the end of the track. There are limit switches, junction boxes and an electrical control panel mounted on the transfer car. 2.3.5 Lift The lift carries two cable reeling drums for the dolly. The supply of control and power to the lift are effected through trailing cables. One end of the cables are connected to the joint box mounted on the lift, the other end connected to the joint box mounted on the vertical wall of the lift well at the lobby level. There are limit switches, junction boxes and an electrical control panel mounted on the lift. The limit switches are acted upon by cams mounted on the vertical wall of the lift well at or near each floor level. 2.3.6 Electrical Motors The speed variation of all the AC electrical motors is achieved by frequency control. The slope is independently adjustable. 2.4 Mechanical System 2.4.1 Stalls The stalls are installed on the floor and receive car wheels on its top. The stalls are manufactured 48â&#x20AC;&#x192; Volume 44

Number 1

March 2014

from galvanized sheet metal indigenously. The galvanized sheet metal are obtained as per IS specification. The manufacturing process involves shearing, die punching, bending and die forming. There are two kinds of stalls, first type is for the front wheels and the second type is for the rear wheels. The stalls for the rear wheels with rectangular corrugations are comparatively longer than the stalls for the front wheels. The stalls are installed on the floor using impact drills and anchoring screws. The floor are cast and finished to a specified tolerance in slope and out of paleness for better performance; since the dollys travel on the bare floor. The stalls are installed along the X-axis parallel to the lift centre lines. They are installed as per the revised layout drawings. The layout drawings required revision as per the surveyed protocol dimensions after the finishing of the civil structural work due to out of verticality, misalignment and bulging of the diaphragm walls. 2.4.2 Dolly All dollys are manufactured and supplied by Proviron SA, Switzerland. These are their patented product. The manufacturing of dollys in India was not a part of technology transfer contract. Local maintenance can always be done, however supply of 2 number dollys were obtained as spare for quick replacement, in case of any maintenance problem. The dolly is a rectangular box of length almost doubles the width. The height is very low so that it can roll below a car. It has four polymer tyred wheels, two on each side. It travels along the long axis (X-axis). It can travel on cement floor and also steel plate track on the transfer car. It has two fork like frames in the front one on each side and two comb like frames in the back one on each side. The frames are normally withdrawn inside the width body of the dolly, while travelling empty and entering below a car. Below the car and at appropriate position both the forks and the combs extend out below the wheels. All the two pairs of forks and combs rise simultaneously below the four wheels to lift the car out of the resting position on the stalls. After travelling to its destination stall, the process is reversed to park the car on the destination stall. The Bridge and Structural Engineer


2.4.3 Transfer Car

2.5 Fire Fighting & VAC

All transfer cars are manufactured indigenously. However the manufacturing was done as per drawings supplied by foreign technological partner. Except for the wheels and cable reeling drums all other bought out items were indigenously procured. Local maintenance can always be done.

2.5.1 Fire Fighting

The transfer car is a rectangular box of length almost three times the width. The height is low so that the recess in the floor in which the tracks are installed are of limited depth. When the transfer car is put on its track in the recess, the track on it for the dolly become flush with the adjacent floor. It has four steel wheels, two on each side. It travels on steel track laid on the recessed floor along the Y-axis. The transfer car has a track on it for dolly. It carries the dolly loaded or empty.

All parking floors have four large air funnels each. Two funnels are for compressed air injection and the rest two are for smoke / used air extraction.

2.4.4 Lift All the six car lifts are manufactured indigenously. However the manufacturing was done as per drawings supplied by foreign technological partner. Except for the guide wheels and cable reeling drums all other bought out items were indigenously procured. Local maintenance can always be done. The lifts are multi wire rope operated with balancing weight. The frame is a cantilever type structure with diagonal bracings below. There is no obstruction on the frame where the dolly is carried. The recess in the basement just in the sitting of the lift is required to accommodate the bottom bracings. The lift is cantilevered out from two joists, supported by wheels, which act as rolling guide. There is a track for the dolly on top of the lift frame. When the lift stops at any floor the track on top is flush with the surrounding floor, containing the delivery/ receiving stalls. The drive motor, gear box and ‘V’ pulleys are on top located above a beam supported on the two guide joists.

Fire detection units were installed all over the parking lot and everywhere else. There was water sprinklers installed as well, which will spray water for suppression in case of fire. 2.5.2 Ventilation

2.5.3 Air Conditioning The commercial complex in the upper floors is fully air conditioned.

3. Salient Structural Scheme, Construction Sequence & Design Features 3.1 Salient Structural Scheme & Construction Sequence The multi-level underground automated car parking structure at Kamlanagar comprises of following major structural components: a)

Construction of 1.0m thick peripheral RCC diaphragm walls (72 number of panels) with a plan diameter of 63m, going down to 30m below ground level.

b)

Construction of 0.6m thick RCC diaphragm walls (66 number of panels) inside the outer peripheral diaphragm walls, going down to 36m below the ground level.

c)

Construction of 173 numbers of bored castin-situ piles of diameter 1.0m, 20m long, with top of pile kept 24m below the ground level. Piling is carried out from the ground level with empty bore for top 24m portion below ground level, with steel liner.

d)

Construction of intermediate basement slabs and basement raft slab in sequence from top to down with clear opening at the centre for removal of earth.

e)

Construction of lift core and closing of the basement floors from bottom up.

2.4.5 Barriers Gates These are electric operated automatic gates at various entrys and exits. These are purchase items.

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  49


f)

Construction of Superstructure, utilities and finishing, Installation commissioning and Trial of Parking Equipments.

The construction of the structure is taken up in 3 distinct phases as described below : Phase-I

: Construction of D`walls and Piles

Phase-II : Excavation & Construction of Underground basement structure Phase-III : Superstructure, utilities and finishing, Installation, Commissioning and Trial of Parking Equipments 3.1.1 Phase I construction (Target : 8 Months): In the first phase, the construction of outer diaphragm walls, inner diaphragm walls and bored cast-in-situ piles are taken up. Sub-Soil investigation has been carried out at site. 6 bore holes of depth upto 50m were taken in the area at the start of project. The Geotechnical Report indicates presence of silty sand for the top 1.0m depth, followed by sandy silt upto 50m below ground level. Intermediate layers of gravelly strata are observed in a few bore holes. Water table was observed at a depth of about 4m-5m below ground. The peripheral diaphragm walls were 1.0m thick, in M30 concrete grade and 30m in depth. A total of 72 peripheral panels were used for covering the full circle of 64.3m diameter (along c/l). Each diaphragm panel was of width 2.805m (average). Intermediate diaphragm walls are provided, which acts as columns to support the basement floors temporarily during the construction phase, till the base raft is cast. These diaphragm walls are isolated walls of 0.6m thick having width of either 4m or 3m and length of 36m below ground level (i,e. About 13m below raft level). Due to space restriction at the construction site, the batching plant was established at a place slightly away from the construction site. The concrete was brought to the site by the transit mixers. 175 nos. of bored cast-in-situ piles are provided upto 14m below the raft level (i,e. 44m below ground level). These piles are cast from the ground level itself with an empty bore for about top 30m length. Fig. 04 shows the arrangement of diaphragm walls and piles in Plan. 50â&#x20AC;&#x192; Volume 44

Number 1

March 2014

Fig. 04: Plan at any Typical Parking Level below Ground

The diaphragm wall panels are provided with stop ends (to support concrete and to form a suitable joint with the next panel). Water bars are keyed into the adjacent panels to make the joint water tight. Mechanical couplers are provided at all the basement floor levels as well as at the raft level, for monolithic connection of the diaphragm wall with the floors subsequently. Photo P3A & 3B shows the construction of Diaphragm Wall in progress. 3.1.2 Phase II construction (Target : 9 Months): After completion of all the foundation works from ground level, the work on Excavation and casting of underground basement structure is taken up in stages. The excavation is done in phased manner, exposing the diaphragm walls part by part and basement floor slabs are cast starting from top level down words. An opening of about 23.5m x 23.5m at the centre is kept in all floors during this top-down construction to facilitate movement of man and machinery, for ease of excavation process, for removal of earth, for ease of concreting for the intermediate floors etc. Photo P4A to 4D shows the construction in progress during this phase. The Bridge and Structural Engineer


Some of the internal diaphragms walls, when exposed after excavation, showed exposed reinforcement, bulging beyond tolerable limits and poor concrete quality, Photo 5 shows a typical diaphragm wall after exposure. Proper testing, diagnosis and strengthening of all these diaphragm walls were carried out, depending

upon the nature and degree of problem at each level before proceeding to the next lower level. The concrete for the basement was delivered both by pump and cranes and BDC (Bottom Discharging Containers). The casting of the base was handled in four quadrants, continuously. The

3B

3A

Photo P3A & 3B : Construction of Peripheral Diaphragm Wall in

4B

4A

Photo P4A & 4B : Excavation & Construction of Basement Floors in Progress

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 51


4C

4D

Photo P4C to 4D: Excavation & Construction of Basement Floors in Progress

sump pump was kept on all the time. Once the base raft is cast, the excavator is removed and the central portion is constructed from bottomup. Filler (non-structural) walls are constructed using brick works. Fig. 05 shows the step by step construction sequence in this phase, which is self explanatory.

Installation, Commissioning and Trial of Parking Equipments were taken up. Photo P6 shows the superstructure during construction.

During the monsoon, when the water table is high outside, seepage was observed in the basement in level (-) 7 (very minor) and level (-) 8 (major). Polymer injection through inserted nozzles were applied on raft as well as external diaphragm wall, which could eventually control the leakage of water. Photo P6: Superstructure during Last Phase of Construction

4. Structural Design Issues

Photo P5 : Condition of some of the Intermediate Diaphragm Walls After Exposure â&#x20AC;&#x201C; Requiring Repair

3.1.3 Phase III construction (Target 7 months) In the last phase, the work above ground (i,e. Superstructure), utilities and finishing, 52â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The structural design and detailing of such a complex structure with phase by phase construction, where the statical system is constantly changing can be a subject matter for another long paper. It would not be possible to cover the design and detailing issues in detail in this paper due to restriction in the number of pages. However, broad design assumptions & philosophy adopted for the structure is outlined here. a.

External diaphragm walls are considered as wall which is designed to take lateral earth and water pressures and axial loads by its circular geometry and by its fixity beyond raft level. The Bridge and Structural Engineer


b.

Internal diaphragm walls are considered

c.

1.0m diameter circular piles have been considered for uplift resistance.

d.

Check for crack width has been performed on exteral and internal diaphragm walls.

e.

Structural design and detailing of Piles has been done as per IS 456 : 2000,

as columns / piles to take axial loads and moments by its fixity beyond raft level. Once the raft is constructed, any subsequent load is shared by both raft as well as the diaphragm walls / piles.

Fig. 05: Sequence of Construction in Phase II

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 53


Clause B-2.2, B-2.2.1, B-2.3 and B-4.2, (Table 22 Permissible Stresses in Steel Reinforcement , Note no. 1)

6. Quality Assurance

f.

All floor plates have been considered as diaphragms connecting all external and internal diaphragm walls, shear walls and lift core walls.

g.

For calculations of earth pressure acting on external diaphragm walls earth considered at rest because of its un-disturbed nature.

There was a separate cadre of QC (Quality Control) engineers to overview, supervise and keep records of all raw materials used and activities appointed by the consultants. Full records of all such activities are preserved in soft and hard copies. The copies are address and date related. There was a unique address system maintained for all activities.

h.

For calculation of water pressure at different construction stages, water levels on outer face of diaphragm walls reduced in consideration to draw down theory.

i.

Water level inside the diaphragm walls considered at 3.0m below the construction level to achieve a dry working area.

j.

For final raft stage inside water level considered at 2m below the bed level.

k.

Draw down of water levels during construction stage is in consideration with soils permeable co-efficient at -25.00m to -30.00m depth and well point dewatering system inside and outside the structure.

5. Maintenance Aspect 5.1 Spares Spares of all fast wearing items, particularly the imported ones are maintained. Fast wearing was determined based on the experience of Proviron BV, the technology supplier. Items like dolly, bearings, electrical and electronic elements are amongst them. The quantity of spares was established following the standard procedure for such items, which is a fully developed engineering process. 5.2 Team A team consisting of civil, mechanical, electrical and electronic engineers with requisite staff are being developed. They will continuously monitor the process and do preventive maintenance. The system is built to help continuous monitoring. There is duplicate equipment in all floors. In case of maintenance shut down of one equipment the other will permit seamless operation. 54â&#x20AC;&#x192; Volume 44

Number 1

March 2014

6.1 QC Cadre

6.2 Raw Material Almost all incoming raw materials are accompanied by MTC (Manufacturerâ&#x20AC;&#x2122;s Test Certificate). However after arrival at site most of the materials (irrespective of having MTC) are sample tested by QC (Quality Control) engineers to conform to the requirements of the relevant IS Code. It is observed that in our country MTC is a formality and sort of initial check. However to assure the quality of the raw material used, the best practice will be testing at site after arrival. 6.3 Concrete Due to space restriction at the construction site, the batching plant was established at a land given by MCD slightly away from the construction site. All raw materials for the concrete like cement, sand and chips are tested at site after arrival. The water supplied by the municipality was tested once. Cube testing was done to develop and confirm the required grade. Multiple concrete cubes were taken and tested at site for each batch of concrete. After the removal of soil, concrete core was taken out from the exposed diaphragm walls, especially near the distressed areas. Strengthening of diaphragm wall by jacketing / other means was carried out at locations where test results indicated reduced strength. 6.4 Reinforcement Bars Fe 500 grade of rebars conforming to IS: 1786 was used. Samples from each lot of rebars were tested at a local accredited laboratory for physical and chemical conformity. Mechanical The Bridge and Structural Engineer


couplers was used for joining of rebars. The couplers ware tested for pull-out capacity at the premises prior to use. 6.5 Finished Goods MPG (Manufacturerâ&#x20AC;&#x2122;s Performance Guarantee) were obtained for all finished items like motors, gearboxes, couplings, steel wire ropes, electrical control gears, electrical power switch gears, cable reeling drums, dollys etc. Photo P7 shows the completed structure (at the time of inauguration)

7. Conclusion 7.1 Population Population is increasing. So is car density. Urban population are getting inflated at the cost of village population world over. Number of cars in cities is increasing at an exponential rate particularly in India. There is no space for parking in cities particularly in the heart of the cities. This system of car parking is ideal for such locations. 7.2 Car Density The parking density per unit area for this kind of automatic car parking is about 2.6 times those of manual parking. The investment is offset by permitting the concessionaire lease earning right of super built commercial properties above ground over an extended period of about 50 years. 7.3 Social Service

PHOTO P7 : The mlcp at the Time of Inauguration

The Bridge and Structural Engineer

No doubt this parking facility will ease the congestion due to parking in vicinity. The capacity of parking facility is designed to accommodate the demand of parking increased by associated commercial area. The capital investment is by developer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 55


RAPID CONSTRUCTION OF MULTISTOREY BUILDINGS IN INDIA

Subhash MEHROTRA Principal Consultant & CEO Mehro Consultants New Delhi, India scmehrotra@mehroconsultants.com

Prof. K.K NAYAR Advisor Mehro Consultants New Delhi, India

Deepak THAKUR Principal Consultant Mehro Consultants New Delhi, India deepakthakur.mehro@gmail.com

Subhash Mehrotra, born in 1949, received his M. Tech (Structural Engineering) degree from I.I.T. Delhi. He is President of IAStructE. He was past President of CEAI. He is currently Chairperson of Membership Committee of FIDIC

Prof. K.K Nayar, B.Tech. (Hons.), from Manchester University M.Sc. (Str. Engg.), from Manchester University. He was professor at I.I.T, Delhi and has 47 years of experience in teaching planning, design and construction of Civil Engg. Structures.

Deepak Thakur, born 1959, received his B. E. Civil Engineering from Nagpur University. He is fellow Member of IAStructE. He was former Superintending Engineer of CPWD.

Summary This paper intends to cover some of the issues regarding building structures like choosing the appropriate structure systems for resisting both gravity & lateral loadings, the analysis and detailing issues, precautions for safety issues while using flat slab system,alternate solution of dissipating seismic energy mechanically. Case study of 40 storey buildings where wind load is a governing case is also given. Keywords: Friction Damper, Air Building, Oblique Frame wind Effect, Structural Forms

1. Introduction India is all set to take off from a third world country to a developed nation of the world. During last few years, there is more and more emphasis on the development of infrastructure at a rapid pace. Therefore the present need for the construction industry is to adopt construction methods which take least time. Thus there is need to evolve new 56â&#x20AC;&#x192; Volume 44

Number 1

March 2014

construction technology & methods. Thus, the design has also to be innovative to cater for fast construction requirements.

2. General a.

As the height of a building increases, its structural form, system and design is significantly affected by lateral forces due to wind and earthquake action. Therefore, in functional planning choice of structural form influences safety and economy.

b.

Though gravitational loading due to weight of materials of construction and probable functional usage can be assessed with certain reliability, there will be some uncertainty in the assessment on the magnitude of lateral loading due to wind and earthquake actions, as they are dynamic and random in nature. Moreover lateral deflection and oscillatory movements of flexible tall structures due to wind can induce considerable discomfort in occupants, unless properly accounted and controlled in the design. The Bridge and Structural Engineer


3. Loading Gravitational loading from tributary areas are transferred to the foundation by vertical elements like walls and columns efficiently, when their vertical continuity from floor to floor is uninterrupted. However, loading due to wind and inertial forces due to earthquake are shared by these elements in proportion to the lateral stiffness of such vertical systems which mobilize floor wise, which will be enhanced when vertically continuous and properly interconnected. During functional planning process, particular attention is given to ensure uninterrupted vertical load path, so that building performance can be assessed with reasonable certainty and designed economically, particularly as both wind and earthquake loadings are dynamic in nature. However, there are, at times constraints due to functional requirements where continuity of vertical column cannot be ensured, like in a Banquet Hall. The basic difference in design for earthquake and wind forces on buildings is that the earthquake governs the design of building having lower time periods i.e. approximately 0.1sec-1.5sec, as maximum response of a structure to a specified ground motion is strongly influenced by its fundamental mode of vibration. Earthquakes are of short duration and impart high energy at lower time periods. When the structure becomes more flexible its time period increases and design will be governed by wind forces, as wind carries higher energy at higher altitudes, have longer time periods of 1.5 secs to 10 secs and induces oscillations both along and across directions. When the structure is very tall, 200 storeys and above, the structural response due to flexibility of the system has a greater impact on comfort level of occupants in addition to its influence on structural integrity. Average human perception threshold to translational vibration ranges from 0.6% of g at 0.1Hz to 0.3%of g at 0.25Hz. The vibration level above 1.2% of g is annoying and above 4% causes nausea and motion sickness. It is recommended that10 year peak resultant acceleration of 1.0-1.5% g for residential building, 1.5-2.0% g for hotels and 2.0-2.5% g for office building. Generally more stringent requirements The Bridge and Structural Engineer

are suggested for residential buildings, which would have continuous occupancy in comparison to office buildings usually occupied only part of the time and whose occupants have the option of leaving the building in advance of a storm. Therefore, the structural response at high wind speed be controlled specially for the acceleration at various frequencies of oscillation of structures.

4. Structural forms & systems a.

Braced Frame Structures.

The lateral resistance is provided by diagonal members, which together with girders form the web. Diagonals will be subjected to tensile or compressive forces depending on the direction of lateral loads. It is a system preferred in steel Construction. Many types of bracings are used namely kneebracing, chevron bracing, single or double diagonal bracing and large scale bracing, interconnecting many storeyes. Primarily they behave as vertical cantilever truss under lateral loading and transfer lateral loads as axial forces in them to the foundation. Eccentric bracing system such as storey height knee-bracings enhances ductility of the steel fame and reduces inertial forces due to earthquake, which is a desirable feature in buildings. b.

Rigid Frame Structure

When joints are rigid and can be detailed as such in concrete frames, ductility can be enhanced by proper detailing of members to reduce intensity of inertial forces. Such system will be suitable for 20-25 storeys. Concrete shear walls by virtue of their high inplane stiffness can be combined with frames to interact horizontally and produce a stiffer and stronger structure. In addition walls can be coupled to provide an excellent system for lateral load resistances in seismic zones. Tube-in-Tube, Hull core and bundled- tubes are other structural forms used for very tall buildings. In these systems the exterior frame tube with closely spaced columns and deep beams interact with interior system of cores or frames. Volume 44

Number 1

March 2014â&#x20AC;&#x192; 57


Through the development of earth quake design response spectra and through time history analysis, earthquake induced design forces can be assessed. By modifying the structural system and geometry, effect of both Earthquake and wind induced forces can be minimized.Time-dependent dynamic forces such as seismic acceleration and short period wind loads can be handled by suitable modification in the structural system. It is well known that beam –column framing without or with shear walls, is one of the best structural system for resisting earthquake loading. Steel bracing are also very effective both in Steel and RCCstructures. Base isolation and energy absorbing devices are now being used in our country. Base isolation systems are found useful for short period structures (less than 0.7 sec.)

response reduction factor considered for special RC moment resisting frame is 5). Thus the Indian code specified seismic force for the elastic response of a structure is limited to only a small fraction of the force, which might be induced in an actual earthquake presuming that there will be sufficient ductility both rotational and translational in the structural systems to dissipate the energy through formation of plastic hinges at appropriate locations in structural members, without leading to excessive deformation and collapse. Thus in general, reliance for survival is placed on the ductility of the structure to dissipate seismic energy while undergoing large inelastic deformations causing bending, twisting and cracking. This assumes permanent damage, repair costs of which could be significant.

As per General Principles and design criteria of IS 1893 (Part 1) : 2002 :QUOTE “The design approach adopted in this standard is to ensure that structures possess at least a minimum strength to withstand minor earthquakes (<DBE), which occur frequently, without damage; resist moderate earthquake (DBE) without significant structural damage though some nonstructural damage may occur; and aims that structures withstand a major earthquake (MCE) without collapse.

Fig. 1: Energy Dissipation during Elastic and Plastic deformation of a member

Lessons learnt from Recent Earthquakes: a.

Conventional construction, even in technologically advanced countries, including the U.S. and Japan, is not immune to destruction. In modern building, avoidance of structural collapse alone is not enough.

b.

The cost of non-structural components (7080%) is much higher than the cost of the structure itself and must be protected.

UNQUOTE

c.

Thus it may be high-lighted here that as per IS Code we are designing a special R.C. momentresisting frame for only 10% of maximum considered earthquake (Design Basis earthquake = ½ maximum considered earthquake and

Buildings of post-disaster importance such as hospitals, Telecommunications, etc. must remain operational.

Alternate Solution

Actual forces that appear on structures during earthquakes are much greater than the design forces specified in this standard. However, ductility, arising from inelastic material behavior and detailing, and over strength, arising from the additional reserve strength in structures over and above the design strength, are relied upon to account for this difference in actual and design lateral loads.”

58  Volume 44

Number 1

March 2014

a.

Establish criteria.

performance

based

design

The Bridge and Structural Engineer


b.

Dissipate seismic energy mechanically, independent of primary structure.

In typical structure without dampers, the inherent damping is merely 2-5% of critical. With the introduction of supplemental damping of 15-30% of critical, the forces and deformations on the structure can be significantly reduced.

5. Types of Dampers a.

Passive damper: dissipate the wind or earthquake induced energy to the structural system by movement of the building and their mechanical properties are pre-defined. One benefit of these passive dampers is that they do not need a source of power to operate and their cost is relatively low since they are not accompanied by electronic devices or mechanical actuators Example Friction Dampers.

b.

Active Dampers: represents an active structural control with several components. In a general sense, they are the building parallel to the control systems like that are used in airplanes when it is on autopilot.

c.

Semi Active Damper: In semi active dampers, the adjustment in the mechanical properties of the device can be achieved. The most commonly used semi-active damper is a passive viscous damper with the external path for the fluid with a control valve.

The overhead water tank in tall buildings also acts as a damper during wind. Since the displacement at top level of the building is high and also the duration of displacement is much higher in wind load case comparison to earthquake load case, the water tanks acts in the opposite direction and reduces the displacement. Thus, for very tall buildings where wind governs, these tanks could be used as a damper. 5.1 Use of Friction Dampers in buildings During a major earthquake, a large amount of kinetic energy is pumped into the building. The manner in which this energy is consumed in a structure determines the level of damage. The Bridge and Structural Engineer

All building codes recognize that it is economically not feasible to reconcile this energy within the elastic capacity of structure. Putting Brakes to Earthquake Out of all the methods so far available to extract kinetic energy from a moving body, the most widely adopted is undoubtedly the friction brake. Mechanical engineers have successfully used this concept for centuries to stop the motion of equipment, automobiles, railway trains, airplanes, etc. No other method has replaced the friction brake. It is the most effective, reliable and economical means to dissipate kinetic energy. Similar to automobiles, the motion of vibrating building can be slowed down by dissipating seismic energy through friction. One of the Friction type dampers is Pall Friction damper developed by Dr. A S Pall an Indian (by origin) structural engineer & settled in Canada. These are now being used as well as manufactured in India.

Fig. 2: Friction damper used in MetLife building on Noida-Greater Noida Expressway

The friction dampers are designed not to slip during wind. During a major earthquake, they slip prior to yielding of structural members. In general, the lower bound is about 130% of wind shear. NEHRP (National Earthquake Hazards Reduction Program, USA) guidelines require that friction dampers are designed for 130% MCE (Maximum Considered Earthquake) displacement and all bracing and connections are designed for 130% of damper slip load. Volume 44

Number 1

March 2014â&#x20AC;&#x192; 59


Variation in slip load from design value should not be more that +-15%.

of one such speedy construction method – Flat Slab Construction.

6. Flat Slab Construction

Fig. 3: Identification of Slip Load

Two way slabs i.e. flat plate or flat slab with drops (Supported on columns) are popular floor systems in office and commercial buildings with regular grid spacing because of their relatively simple formwork and the potential for shorter storey heights due to their shallow profile. The speed of construction is relatively very fast in comparison to beam and slab construction. Therefore, the present need for the construction industry is to adopt flat plate or flat slab with drops and thereby minimize construction time and also facilitate provision of additional floor plate within the same restricted height of the building. Slab-column frames are frames that meet the following conditions:

Fig. 4: Hysteretic Loops of Different Dampers (Area of loop indicates energy dissipation or damping efficiency)

a.

Framing components shall be slabs, columns, and their connections.

b.

Frames shall be of monolithic construction that provides for moment and shear transfer between slabs and columns and

c.

Primary reinforcement in slabs should contribute to lateral load as well as gravity loads.

The flexibility of a slab-column frame can lead to large lateral deformation, which may lead to loss of its vertical load carrying capacity. Therefore, in regions of high seismic risk, slab – column frames are used in conjunction with beam – column moment frames and or shear walls.

Fig. 5: Central Plates for In-Line Friction Dampers being fabricated.

After brief synopsis on building structural forms and ways to dissipate energy from earthquake and wind forces, the article moves from design to construction. Below segment is an example 60  Volume 44

Number 1

March 2014

Fig. 6: Flat Slab Construction for an office building – I.T. Park, Chennai

Slab – column connections in structures subjected to earthquake or wind loading must transfer The Bridge and Structural Engineer


forces due to both gravity and lateral loads. This combination can create large shear and unbalanced moment demands at the connection. Without proper detailing, the connection can be susceptible to two-way (punching) shear failure during response to lateral loads.

was partly attributed to a high flexibility combined with low-ductility capacities of the slab-to-column connection. Some views and observations about flat-slab system. Slab – column frames are not ductile and in the in-elastic range of deformation, they are likely to lose their capacity to carry the gravity load and transfer it to columns, particularly under cyclic loading conditions experienced during high seismic vibration. So this structural system has to be used only if it is integrated with ductile systems, such as Beam-column frames, coupled shear walls, core-walls etc, which will relieve the slab-column system from sharing a major proportion of the horizontal forces during seismic activity. Generally the shear wall and peripheral beamcolumn frames as a primary ductile system should have sufficient stiffness to control drift as well as torsional displacement of the total structure. As per IS Code 1893 (Part 1): 2002 - 5.4.11.2 Deformation compatibility of non-seismic members. QUOTE “For buildings located in seismic Zones IV and V, it shall be ensured that the structural components, that are not a part of the seismic force resisting system in the direction under consideration, do not lose their vertical load-carrying capacity under the induced moments resulting from storey deformations equal to R times the storey displacements calculated as per 5.4.11.1.

Fig. 7: Effective Width for Reinforcement Placement in Edge and Corner Connections (REF. ACI 318-05 Fig R.21.12.6.1)

The seismic performance of reinforced concrete structures with flat-slab construction has demonstrated the vulnerabilities of the system. For example, following the 1985 Mexico City earthquake, punching shear failures were noted in building with flat-plate construction. This failure The Bridge and Structural Engineer

For instance, consider a flat-slab building in which lateral load resistance is provided by shear wall. Since the lateral load resistance of the slab-column system is small, these are often designed only for the gravity loads, while all the seismic forces is resisted by the shear walls. Even though the slabs and columns are not required to share the lateral forces, these deform with rest of the structure under seismic force. The concern is that under such deformations, the slab-column system should not lose its vertical load capacity.” Volume 44

Number 1

March 2014  61


UNQUOTE

b.

Peripheral Beam-column-wall framing coupledwall systems and cores in the service area should be provided such that lateral stiffness mobilization of these systems:-

In a flat slab even if the factored shear stress is less than the permissible, nominal shear stirrups shall be provided in the drop panel as they increase the ductility.

c.

In column strip minimum four numbers of bottom bars shall pass through the column core.

d.

In column strip 25% of the top reinforcement provided at column support shall be continuous throughout the length.

e.

In column strip all bottom bars provided at mid span shall be continuous under column i.e. no curtailment of bottom bars shall be done.

f.

Use high strength concrete in flat slab.

g.

Preferably adopt flat-slab with drop instead of flat plate as the flat plate increases the weight of the structure and gives limited confined shear zone around columns and has low ductility.

i)

Relieve the seismic shear on flat-slabcolumn system to less than 25% of the total shear at that level.

ii)

Drift at DBE level is not greater that .004 as specified. and

iii)

Torsional irregularity is only marginal.

ACI 318-05 has incorporated special provisions related to the lateral-load capacity of slab-column connections in structures located in regions of high seismic risk or structures assigned to high seismic performance or design categories.

7. Case study with wind governing (load case) - Air Building (G+40) at Uniworld City Kolkata

Fig. 8: Design Storey Drift Ratio DR vs Gravity Shear Ratio. (ACI 318-05 Fig.R21.11.5)

The project consists of the construction of AIR building, 40 floors in height on a large basement of car parking, which is fairly rectangular in size at Uniworld City Kolkata. Structural system

Vu = Factored shear force on the slab critical section for two way action ÎŚ = Strength reduction factor for shear Vc = The nominal shear strength carried by the concrete The design DR (story drift divided by story height) is higher of adjacent stories above & below slabcolumn connection. Neither IS 456 nor IS-13920 provide appropriate detailing of Flat Slab in Seismic Zones.Therefore some recommendations from ACI codes should be adopted. The following should be considered:a.

Use simple and regular configuration in plan and elevation of the structure.

62â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The structural system consists of shear wall/core interacting with beam-column frames. Special investigation For the 40 storey building, it was necessary to investigate the dynamic effect of wind along and across the direction of wind. Therefore, design pressures and forces have been ascertained using a rigid (pressure) model of the structure in a wind tunnel. This test was also necessary to ascertain the venturi-effect of flow of high wind through the continuous central vertical opening provided at upper levels. The test was done at I.I.T. Roorkee. Based on wind tunnel test, it was possible to assess the simultaneous actions of wind on the structure, both along and across, during the The Bridge and Structural Engineer


motion of wind. Based on Wind Tunnel Test the design forces were given by I.I.T. Roorkee for wind motion from 0 to 1800 at 450 intervals with respect to the minor axis. Stand alone and interference conditions was also considered. Distribution of wind loading along the height of the building as given in IS:875 has been scaled to match the base shear assessed through the wind tunnel tests. Load combination has been modified to account for the simultaneous action of both along and across, during wind motion parallel to the incidence considered. Alterations in the sizes of few members such as columns and walls were required based on the enhanced forces as per wind tunnel tests.

Design & detailing of RCC Structure Some of the various load considered are as follows:1.

1.5 (D.L+ Reduced L.L) as per Fig. 1 of IS: 875 – 1987(Part-2) (For design of vertical membersonly)

2.

1.5 (D.L ± E.Q in X-direction)

3.

1.5 (D.L ± E.Q in Z-direction)

4.

1.2 (D.L + K1L.L ± E.Q in X-direction)

5.

1.2 (D.L + K1L.L ± E.Q in Z-direction)

6.

0.9 (D.L) + 1.5 E.Q. in X-direction

7.

0.9 (D.L) + 1.5 E.Q. in Z-direction

8.

1.5 (D.L ± E.Q in X-direction ± 0.3E.Q in Z-direction )

9.

1.5 (D.L ± E.Q in Z-direction ± 0.3E.Q in X-direction )

Seismic loads Seismic loading has been considered as per IS: 1893(Part-1) -2002. Dynamic analysis has been carried out using response spectrum. The Time period of the structure has also been worked out using STAAD Pro software. The building has been designed for base shear based on codal time period in accordance with i.e. 7.8.2 of IS: 1893-2002 using modification factor = `VB/VB where`VB is calculated based on codal time period and VB is calculated based on time period given by STAAD Pro software. Wind loads Wind loads have been worked out based on basic wind speed of 50m/s for a Return Period of 50 years. Based on the parameters listed above, average wind pressures including external pressure co-efficient are calculated at different heights. This has been, scaled appropriately based on the special investigation report of Wind Tunnel Test. Analysis, model and software used Super Structure:- The building has been analyzed as a 3-dimensional structure using STAAD Pro software. Rigid diaphragm action of the floor has been stimulated in distributing lateral forcesdue to Earthquake/Wind. Foundation: 1000mm dia bored Cast-in-Situ piles 40m long with pile caps.

The Bridge and Structural Engineer

combinations

10. 0.9 (D.L) + 1.5 (E.Q. in X-direction + 0.3E.Q in Z-direction ) 11. 0.9 (D.L) + 1.5 (E.Q. in Z-direction + 0.3E.Q in X-direction ) 12. 1.2 (D.L + K1L.L ± E.Q in X-direction ± 0.3E.Q in Z-direction) 13. 1.2 (D.L+ K1L.L ± E.Q in Z-direction ± 0.3E.Q in X-direction) 14. 1.5 (D.L ± W.L in X-direction± K2W.L in Z-direction) 15. 1.5 (D.L ± 1.1W.L in Z-direction± K3W.L in X-direction) 16. 1.2 (D.L +L.L ± W.L in X-direction± K2W.L in Z-direction ) 17. 1.2 (D.L +L.L ± 1.1W.L in Z-direction± K3W.L in X-direction) 18. 0.9 (D.L) + 1.5 (W.L. in X-direction± K2W.L in Z-direction) 19. 0.9 (D.L) + 1.5 (1.1W.L. in Z-direction± K3W.L in X-direction) 20. 1.5 (D.L+ L.L) Note: Load combinations from (14) to (19) are based on wind tunnel test results using factors K2 & K3 as per Wind Tunnel test results.

Volume 44

Number 1

March 2014  63


D.L =Dead loads

(Ductile detailing of reinforced concrete structures

L.L = Live loads

subjected to seismic forces).

E.Q= Earthquake loads

Material of Construction

W.L=Wind loads

All RCC works for columns, beam and slabs are

K1= 0.25 For live load class upto 300Kg/m2

based on design mix concrete.

Detailing of R.C.C. beams and columns conforms with IS: 456-2000,IS: 4326 (Earthquake resistant design and construction of buildings),IS: 13920

For columns and core walls M50 for lower storeys, M40 for middle level storeys, and M35 for remaining storeys are being used.

Fig. 9: Typical Structural Arrangement of 40 storeyed Air building in Kolkata

Architect: M/s Pankaj Sangwan Associates Structure Consultant: M/s Mehro Consultants

Fig. 10: Model of Air Building at Kolkata

64â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


8. Conclusion In this paper, various structural forms to resist lateral forces like wind and Earthquake have been considered along with ways to dissipate the huge kinetic energy induced in the structure by these lateral forces. One such method of mechanically dissipating energy by the use of friction damper has been covered in detail. The Flat Slab method of construction has been covered as a speedy method of construction along with design criteria to meet requirements of high seismic zones. In the end, a case study on 40 storey building in Kolkata covers the analysis method adopted for its design to resist wind and earthquake loads.

9. References and Acknowledgements

Fig. 11: Construction stage of Air Building at Kolkata

The Bridge and Structural Engineer

1.

Council on Tall Buildings and Urban Habitat

2.

Dr. A.S. Pall

3.

National Earthquake Hazards Reduction Program, USA

4.

Building code requirements for structural concrete (ACI 318-05) and commentary (ACI 318 R-05).

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 65


ROAD MAP TOWARDS NET ZERO ENERGY BUILDING Ms Minni Sastry has done B.Arch from Delhi and Masters in Energy and Environmental studies from AA School of Architecture, London. She has been working in the field of Sustainable buildings for the last 10 years and is currently working as Fellow and Area Convener for Centre for Research on Sustainable Building Science at TERI, Bangalore.

Minni SASTRY Fellow & Area Convenor The Energy and Resources Institute (TERI) Bangalore, India minnim@teri.res.in

Summary To reduce the gap between demand and supply of energy of buildings in India, it is important that policies are framed to provide standards and road map for implementing net zero buildings in India. This can be achieved by methodologies that involve climate analysis, bioclimatic architectural design and selection of materials, innovative system design for air conditioning and lighting. The result of these methodologies would be reduction in energy demand which is met by renewable resources.

was then met by renewable resources which includes biomass gasifier, solar PV panels and wind. There are smart controls installed, which manage the demand based upon the resources available.

2. Approach In all its projects TERI tries to achieve net zero energy buildings, which refers to a building with zero or net negative energy consumption. Following is the approach followed to achieve net zero energy buildings:

Keywords: Net Zero Energy Building, Climate Analysis, Embodied Energy Reduction, Energy Performance Index

1.

Climate and micro climate analysis

2.

Bioclimatic architectural selection of materials.

1. Introduction

3.

Innovative system design (air conditioning and lighting)

4.

Integration with renewable energy and interaction with the grid

5.

Intelligent controls and BMS.

Climate change requires designers to innovate new ways to design buildings, that are not responsible for green house gas emissions. One of the ways is to design net zero or net positive buildings.The Centre for Research on Sustainable Building Science had started the journey about two decades back. Since then TERI has been involved in evolving the landscape for sustainable buildings in India. In early 1990s TERI had build a self sustainable building complex named RETREAT in its GualPahari complex. The building does not consume electricity from the grid. State of the art technologies such as optimised architectural design, earth coupled cooling system had helped reduce the energy demand of the building. The reduced demand 66â&#x20AC;&#x192; Volume 44

Number 1

March 2014

design

and

Climate and micro climate analysis is one of the first steps to determine the bioclimatic architecture design features, and low energy cooling/heating strategies. In micro climate analysis, for most of the building projects in TERI, outdoor wind flow analysis is carried out(Fig.1), to explore the potential of achieving thermal comfort through natural ventilation. Solar irradiation analysis (Fig.2) is carried out to explore the availability of natural light outside the facade, for reducing the dependence on artificial lighting. Urban het The Bridge and Structural Engineer


island studies are carried out to determine the microclimate air temperatures, strategies are evolved to reduce microclimate temperature in the tropical climate, which in turn results in reducing the dependence upon air conditioning.

Fig. 1: Outdoor flow analysis for a high rise residential project to determine the wind speeds available

Fig. 2: Outdoor solar radiation intensities received by various facades in a dense campus development

Fig. 4: Pre stressed pile foundations

4. Operational Energy In order to reduce the operational energy demand, in tropical cities of India it is important to minimise the cooling demand by optimizing the architectural design, selection of material, optimized window wall ratio, daylight integration, optimized artificial lighting design, low energy cooling systems to provide thermal comfort , efficient electrical systems and integration of renewable energy.

3. Embodied Energy Reducing the embodied energy of construction material and technologies used for building is another step towards net zero building. A few examples of such technologies are: Pre-stressed slabs, hollow floors/roof slabs, precast reinforced bricks, micro concrete roofing, composite column; pre cast concrete blocks, rat trap masonry bond, light-weight concrete blocks etc. Fig. 5: Optimized Window Wall Ratio

Fig. 3: Pre tensioned slabs being cast in situ Fig. 6: Daylight Factor Analysis in an office building

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 67


5.

Energy Performace Index(EPI)

Energy Performance Index is measured as Annual Energy consumption /m2/annum. It is observed during analysis that by integrating low energy design technologies, EPI can be reduced upto 25% in comparison to a business as usual scenario. On integration of energy efficient systems this is further reduced to 50-55%, buildings that which integrate low energy technologies along with energy efficient systems along with controls, the EPI could be reduced by as high as 65-70%. Integrating renewable energy with such reduced EPI makes renewable energy more financially attractive case.

6.

Case study

In Bangalore TERI has designed a solar passive silkworm rearing house where stringent thermal comfort indoor environment is achieved without use of any electro mechanical systems. visual comfort is achieved through north lights in day time, without use of artificial lights. To achieve thermal comfort, state of art technologies such as trombe wall, insulated roof pond for radiant cooling, solar chimneys, evaporative cooling and other design strategies are incorporated. Graph showing outside conditions and inside environment conditions achieved is shown.

Fig.8: Hourly Temperature profile on 6th April 2012 during Rearing 2

7. Fig. 7: Constructed Solar Passive Silkworm Rearing House in Bangalore

68

Volume 44

Number 1

March 2014

Conclusions

To reduce the gap between demand and supply of energy in India, it is important that policies are framed to provide standards and road map for implementing net zero buildings in India so that the building demand is met by Renewable Resources.

The Bridge and Structural Engineer


Bridge Rehabilitation and Maintenance Works, Part-1

& Bridge Asset Management, Part-2

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 69


55000

70â&#x20AC;&#x192; Volume 44

70000

Number 1

55000

March 2014

55000

70000

55000

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 71


72â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 73


74â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 75


76â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 77


78â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 79


80â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 81


82â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 83


84â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


INCREMENTAL DYNAMIC ANALYSIS OF REINFORCED CONCRETE FRAME WITH APPLICATION ON GRID COMPUTING

Amit MELANI PhD Research Scholar Shri G.S. Inst. of Tech. & Sc. Indore, MP, INDIA amit_melani@hotmail.com

Rakesh KHARE Professor Shri G.S. Inst. of Tech. & Sc. Indore, MP, INDIA rakeshkhare@hotmail.com

Mahesh SHAH Associate Director, CAE Group,C-DAC Pune, Maharashtra, INDIA mahesh@cdac.in

Pallavi GAVALI Sr. Tech. Officer, C-DAC Pune, Maharashtra, INDIA pallavig@cdac.in

Amit Melani received his Bachelor degree in Civil Engineering in 2003 and Masters degree in Structures in 2005 from SGSITS, Indore. Then worked as a Structural Design Engineer in a private consulting firm from 2005-2010. Afterwards, he worked for two years in Department of Science & Technology, New Delhi funded research project from 2010-2012 and also registered himself for PhD at RGPV Bhopal.

Rakesh Khare received his Bachelor degree in Civil Engineering in 1985 and Masters degree in Stress and Vibrations Analysis of Machinery & Structures in 1987 from Bhopal University. He joined SGSITS in 1988 and did his PhD in 1996 from DAVV Indore. He has done One Semester Certificate Course at IIT Kanpur on Earthquake Resistant Design of Structures and six months Post Doctoral Research Training at University of Canterbury, Christchurch, NZ in 2005-2006. He presently is professor at SGSITS, Indore.

Mahesh Shah received his Bachelor degree from Govt. College of Engineering Pune and Masters degree in Aeronautical Engineering from IIT Mumbai in 1991. Presently he is working in C-DAC, Pune as an Associate Director for Computer Aided Engineering (CAE) group.

Pallavi Gavali received her Bachelor degree in 2004 and Masters degree in 2006 from Govt. College of Engineering Pune. Presently she is working as a Senior Technical Officer at C-DAC, Pune.

Summary In this paper, a methodology to assess seismic performance of a reinforced concrete frame based on Incremental Dynamic Analysis (IDA) is presented. Also, a web portal is developed which enable users to perform IDA using OpenSees on Grid Garuda facility. Keywords: RC frames; nonlinear time history analysis; intensity measure; fragility curves; The Bridge and Structural Engineer

yielding; collapse; problem solving environment; high performance computing.

1. Introduction The behavior of reinforced concrete structures under the effect of ground motions has always been a subject of investigation, especially in seismic regions. Therefore, seismic evaluation of a building is important for identifying the response of a structural system under the effect of potential Volume 44

Number 1

March 2014â&#x20AC;&#x192; 85


seismic ground motions. The earthquakes from the past decade have emphasized the need for risk assessment of buildings to estimate their potential damage from future earthquakes. To predict the response of these structures from future ground motions, probabilistic seismic performance assessment procedures using emerging analysis techniques like Incremental Dynamic Analysis (IDA) are required. This entails appropriately scaling each ground motion record to cover the entire range of structural response, from elasticity, to yielding, and finally global dynamic instability. In this study, a methodology based on IDA to assess probabilistic seismic performance and to determine the damage levels (i.e. yielding and collapse) and their probability to survive at various ground motion intensities is presented. Also, OpenSees is made available to users on

C-DAC’s High Performance Computers and Grid Garuda computing facility sequentially and parallelly by very user friendly web portal facility for job submission and results to obtain the results. The IDA is performed on a three story low rise RC frame which is seismically designed for zone-V as per Indian standard code of practice IS 1893 (Part 1): 2002 and detailed as per IS 13920: 1993. The load calculations for the present three story frame are made according to the low rise commercial structure, which enhanced the fundamental period in its first mode of vibration as 0.8 seconds which is in the range of mid-rise structures. Hence a set of 20 ground motion records used by Vamvatsikos and Cornell (2002) to analyse mid-rise buildings is selected for performing IDA for the representative frame as shown in Table 1.

Table 1: Suite of 20 ground motion records used No

Event

Year

Station

Φ1

M2

R3 (km)

PGA (g)

90

6.9

28.2

0.159

1

Loma Prieta

1989 Agnews State Hospital

2

Imperial Valley

1979 Plaster City

135

6.5

31.7

0.057

3

Loma Prieta

1989 Hollister Diff. Array

255

6.9

25.8

0.279

4

Loma Prieta

1989 Anderson Dam

270

6.9

21.4

0.244

5

Loma Prieta

1989 Coyote Lake Dam

285

6.5

22.3

0.179

6

Imperial Valley

1979 Cucapah

85

6.9

23.6

0.309

7

Loma Prieta

1989 Sunnyvale Colton Ave

270

6.9

28.8

0.207

8

Imperial Valley

1979 El Centro Array #13

140

6.5

21.9

0.117

9

Imperial Valley

1979 Westmoreland Fire Sta.

90

6.5

15.1

0.074

10

Loma Prieta

1989 Hollister South & Pine

0

6.9

28.8

0.371

11

Loma Prieta

1989 Sunnyvale Colton Ave

360

6.9

28.8

0.209

12

Superstition Hills

1987 Wildlife Liquefaction Array

90

6.7

24.4

0.180

13

Imperial Valley

1979 Chihuahua

282

6.5

28.7

0.254

14

Imperial Valley

1979 El Centro Array #13

230

6.5

21.9

0.139

15

Imperial Valley

1979 Westmoreland Fire Sta.

180

6.5

15.1

0.110

16

Loma Prieta

1989 WAHO

0

6.9

16.9

0.370

17

Superstition Hills

1987 Wildlife Liquefaction Array

360

6.7

24.4

0.200

18

Imperial Valley

1979 Plaster City

45

6.5

31.7

0.042

19

Loma Prieta

1989 Hollister Diff. Array

165

6.9

25.8

0.269

20

Loma Prieta

1989 WAHO

90

6.9

16.9

0.638

86  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The seismic zone factors incorporated in the Indian standards reflect the values of effective peak ground acceleration (PGA) for the Maximum Considered Earthquake (MCE). The magnitude of the earthquakes associated with the zone factors are M6 (or less), M7, M8 and M9 (and above) for zones II, III, IV and V respectively. In the present case, the frame is designed for zone-V having effective peak ground acceleration value as 0.36g corresponding to a M9 or bigger earthquake. The 2011 Japan earthquake reported that the Tsunami in Japan was due to a M9 earthquake which was preceded by a M7.2 and three M6+ foreshocks two days before the main event. Aftershocks from this earthquake included one M7, almost 50 M6, and hundreds of M5 and smaller events. In addition, this event also triggered separate earthquakes in western Honshu (M6.1) and offshore northwestern Honshu (M6.6). The horizontal PGA values along the coast recorded by a Japanese network (NIED) were above 2g with a maximum value of 2.7g. The M6.3 Christchurch earthquake in February 2011 recorded vertical and horizontal PGAs up to 2.2g and 1.2g respectively. Similarly, the earthquake of Canterbury (M7.1) and Haiti (M7) in 2010 induced PGAs in excess of 1.26g and 0.5g respectively. However, the 2001 Bhuj earthquake in India observed some shakings of around 0.6g PGA which exceeded the code based MCE value of 0.36g. Therefore, based on these studies seismic evaluation with probabilistic analysis is done here for severe seismic prone regions of India i.e. zones which are likely to experience severe earthquakes.

Here the frame is designed as per the provisions of IS 1893 (Part 1): 2002 and detailed as per IS 13920: 1993 which is the common design standard used by engineers to design structures for seismic prone regions in India. Apart from this, using the capacity design concept the shear strength of the columns is calculated from IS 13920: 1993 and due to the limitations of IS 13920: 1993, flexural strength is calculated from report of American Concrete Institute (ACI 318-08). The frame is designed and results are compared with the common design practice. Here a PGA value higher than the current code based MCE and DBE values is considered and comparative analysis is done in order to check the safety of the representative frame under future probable severe shakings. 1.1 Structural Configuration of RC Frame Considered Low rise RC frame buildings (with 3-5 stories) are being built on large scale in urban India. Reinforced concrete is the popular material for building construction in India because it is cheaper than structural steel. Also, construction in RC is considered to be labor intensive and requires lesser high-tech tools, infrastructure and skills, than those in structural steel. The frame considered in the present study (Fig.1) is a typical three story RC frame which is seismically designed and detailed for zone-V as per IS 1893 (Part 1): 2002. This frame is used to assess probabilistic seismic performance and to determine the structural performance and damage levels.

Fig. 1: Elevation of the representative RC frame

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 87


The present RC frame is a 30m wide and 10.8m high with five equal bays of 6m in horizontal direction and three equal stories of 3.6m modeled vertically. The sizes of beams and columns and the reinforcement at each floor level is kept same so as to minimize the complications in modeling the frame and to avoid the occurrence of rigorous analysis results while studying the behavior of frame. The frame is typically analysed and designed for dead loads and live loads for

a commercial building at each floor and then in combination with the seismic forces as per IS 1893 (Part 1): 2002. The frame considered is an intermediate frame spaced at 4m from other adjacent frames in transverse direction. The loads considered over the frame are shown in Table 2. Grade of concrete considered is M25 and for steel Fe-415. The load combinations and load factors were adopted as per IS 1893 (Part 1): 2002.

Table 2: Loads considered for the representative RC frame Type of Loading

Load intensity

Transverse width

UDL intensity

Dead Load (DL) inclusive of self-weight

5.0 KN/M2

4.0M

20 KN/M

Live Load (LL)

5.0 KN/M2

4.0M

20 KN/M

10 KN/M

Load from infill walls Total distributed load over beam 1.1.1 F1 Frame

50 KN/M Table 4: Member details for F2 frame

The frame is designed as per IS 1893 (Part 1): 2002 and detailed as per IS 13920: 1993 by incorporating provisions of capacity design for shear in beams, columns and beam-column joints but the capacity design for flexure is not incorporated as this clause is not available in IS 13920: 1993 Table 3.

Members Sizes (mm)

Columns

Beams

500 x 500

300 x 500

Percentage steel (%) 2.3%

As per IS 13920: 1993 provisions

2.5%

As per IS 13920: 1993 provisions

Table 3: Member details for F1 frame Members Sizes Percentage (mm) steel (%)

Stirrup details

Columns

400 x 400

2.35%

As per IS 13920: 1993 provisions

Beams

300 x 500

2.5%

As per IS 13920: 1993 provisions

1.1.2 F2 Frame F1 frame is further revised by including capacity design concept of columns in flexure as per ACI 318-08. The sizes and reinforcement of beams for F2 frame are kept same as F1 frame but column sizes and its reinforcement are revised due to introduction of capacity concept of columns in flexure (Table 4).

88  Volume 44

Number 1

March 2014

Stirrup details

1.1.3 F3 Frame Contribution of floor reinforcement to beams requires even stronger capacity of columns (Clause 21.6.2.2, ACI 318-08). Therefore, column sizes and its reinforcement are revised one level higher from F2 frame to incorporate such contributions as shown in (Table-5). The beams and columns of all the frames are well confined following the ductility provisions of IS 13920: 1993. Table 6: Member details for F3 frame Members Sizes Percentage (mm) steel (%)

Stirrup details

Columns

600 x 600

2.2%

As per IS 13920: 1993 provisions

Beams

300 x 500

2.5%

As per IS 13920: 1993 provisions

The Bridge and Structural Engineer


2. Incremental Dynamic Analysis (IDA) Incremental Dynamic Analysis is a parametric analysis method that has recently emerged in several different forms to estimate more thoroughly structural performance under seismic loads. It involves subjecting a structural model to one (or more) ground motion record(s), each scaled to multiple levels of intensity, thus producing one (or more) curve(s) of response parameterized versus intensity level. It has been observed that IDA is a valuable tool that simultaneously addresses the seismic demands on structures and their global capacities. Also, IDA has been extensively applied in Performance Based Earthquake Engineering (PBEE) such as in identification of critical ground motions, for multi-level seismic performance assessment, and for seismic risk assessment of bridges, and seismic RC frame buildings. Here, the inelastic dynamic analysis of reinforced concrete building structures program IDARC2D (Version 7.0) is used by modifying its source code to perform IDA.

3. Hysteretic Model Used for IDA The release of IDARC includes two types of complex hysteretic models, the polygonal and smooth hysteretic models. The Polygonal Hysteretic Model (PHM) refers to models based on piecewise linear behavior which are most often motivated by actual behavioral stages of an element or structure, such as initial or elastic behavior, cracking, yielding, stiffness and strength degrading stages, crack and gap closures etc. The types of PHM which IDARC includes are trilinear model, bilinear model and vertex oriented model which is same as trilinear model except the direction of the hysteretic loops to its previous peak response. On the other hand, Smooth Hysteretic Model (SHM) refers to the models with continuous change of stiffness due to yielding, but sharp changes due to unloading and deteriorating behavior. In this study, the vertex oriented model for columns and beams is used with modified four-parameter momentcurvature relationship. In order to use four parameter hysteresis model in nonlinear dynamic analyses, four factors The Bridge and Structural Engineer

need to be quantified for the structural type being analysed. Therefore, the values of four parameters HC, HBD, HBE and HS based on degradation condition are used in the hysteresis models for conducting IDA. The general meaning of the parameters can be given as; an increase in HC retards the amount of stiffness degradation; an increase in HBD, HBE accelerates the strength deterioration; and an increase in HS reduces the amount of slip. The values of four parameters used for degradation conditions are shown in Table-6. Table 6: Values of four parameters for degradation conditions Degradation condition

HC

HBD

HBE

HS

Mild

15.0

0.15

0.08

0.40

Moderate

10.0

0.30

0.15

0.25

Severe

4.0

0.60

0.60

0.05

The severe degradation will occur for elements lacking in confined reinforcement detailing or generally detailed as per IS 456: 2000 only. Whereas, moderate and mild degradation will occur for elements detailed using capacity design concept along with ductility provisions.

4. Web Portal Facility OpenSees (Open System for Earthquake Engineering Simulations) software framework sequential and parallel version is available on C-DACâ&#x20AC;&#x2122;s HPC facility and a fully user friendly input submission web portal facility is available for the user to submit their RCC building frame models in TCL (Tool Scripting language) for carrying out incremental dynamic analysis on parallel processors. This will ultimately save the simulation time for IDA for users who were not fully aware of high performance computing and job submission scripting. Web portal is an easy platform for them to use OpenSees on HPC for Earthquake Simulations using IDA for RCC frame buildings. Web portal also contains the EQ data and output results for sample example problems that are useful for the users for building models and simulations. Volume 44

Number 1

March 2014â&#x20AC;&#x192; 89


Problem-solving environment (PSE) is a platform for solving broad range of computational problems in science and engineering on a wide range of computer systems. PSE provides support for problem formulation, algorithm selection, and solution visualization. It supports collaboration among people and enables execution of different codes on diverse conglomeration of machines. A typical PSE allows users to define and modify problems, choose solution strategies, use appropriate hardware and software resources, and visualize and analyze results. A user communicates with the PSE in the language of problems, not in the language of particular operating system, programming language, or network protocol. These applications are the first kind of facility in India, which will utilize C-DACâ&#x20AC;&#x2122;s HPC resources to provide solutions to complex problems in the areas structural and earthquake engineering. For the Earthquake Engineering Simulations and Design applications it is planned to develop a web based computational portal. This portal would be developed and deployed on a separate server, which will act as front end for entire application running on each cluster of the HPC resources of C-DAC. The various databases and executable required for running the applications would be replicated through the structural mechanics problem solving portal facility. The users will get time bound access to run their job through the portal with user name and password facility. Any query coming in from the users through the Portal, would get automatically scheduled and solutions for the same will be made available through mailing and message board facility. A web browser at the client side is the only requirement for the user who needs to access this problem solving facility. The biggest advantage of such a design is that, user anywhere in the world can access the portal and fire a job on this problem solving environment facility for earthquake engineering analysis problems.

90â&#x20AC;&#x192; Volume 44

Number 1

March 2014

5. Results and Discussions 5.1 Based on IDA Results of IDARC The maximum inter story drift ratio is used as Engineering Demand Parameter (EDP) and PGA is selected as Intensity Measure (IM). The maximum inter story drift ratios obtained from the time-history analyses are plotted against the ground motion intensities. The relative intensity at which this curve became flat is then considered to be the collapse capacity of the structure and the point at which the curve leaves the linear path considered to be the yield capacity of the structure. To determine the collapse capacity of the structure, ground motions are scaled up from a low value of IM to higher values i.e. an increment of 0.005g in PGA is selected in order to capture the collapse capacity of the frame with a reasonable sensitivity. Then using the yield and collapse capacities of frames the fragility curves are constructed in terms of PGA based on the assumption that these can be expressed in the form of two-parameter lognormal distribution functions. The zone factor given in IS 1893 (Part 1): 2002 for a particular zone implicitly represents the PGA of the Maximum Considered Earthquake (MCE, 0.36g for Zone-V) with 2475 years return period which is lowered to Design Basis Earthquake (DBE, 0.18g for Zone-V) with 475 years return period. Moreover, the code assumes that the ratio of PGA of MCE to the PGA of DBE is 2. Based on this assumption one more hazard level is considered as 0.72g PGA in the fragility curves which can be treated as MCE value for future probable shakings with higher amplitudes. The frames with severe degradation does not reflects true behavior of degrading parameters, as severe degradation is possible for frames with low level of confinement. In present case frames are well confined using capacity design concepts with ductility provisions, hence probability of damages in mild and moderate conditions are of major concern. However, from the results of severe degradation the probabilities of damage to frames at low level of confinement can be assessed (Table 7, Table-8, and Table 9).

The Bridge and Structural Engineer


(a)

(b)

(c) Fig. 2: Fragility curves for yielding and collapse damage states for F1 frame with column sizes 400x400 and beam sizes 300x500 for all degradation conditions, (a) Mild; (b) Moderate; (c) Severe

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 91


(a)

(b)

(c) Fig. 3: Fragility curves for yielding and collapse damage states for F2 frame with column sizes 500x500 and beam sizes 300x500 for all degradation conditions, (a) Mild; (b) Moderate; (c) Severe 92â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


(a)

(b)

(c) Fig. 4: Fragility curves for yielding and collapse damage states for F3 frame with column sizes 600x600 and beam sizes 300x500 for all degradation conditions, (a) Mild; (b) Moderate; (c) Severe

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 93


Table 7: Probability of yield and collapse damage states based on degradation conditions at DBE (0.18g PGA) Type of Frame

Mild

Moderate

Severe

Yield

Collapse

Yield

Collapse

Yield

Collapse

F1

20%

2%

13%

2%

25%

7%

F2

0%

0%

1%

0%

4%

0%

F3

0%

0%

0%

0%

0%

0%

Table 8: Probability of yield and collapse damage states based on degradation conditions at MCE (0.36g PGA) Type of Frame

Mild

Moderate

Severe

Yield

Collapse

Yield

Collapse

Yield

Collapse

F1

72%

33%

62%

30%

80%

58%

F2

20%

10%

24%

4%

48%

17%

F3

10%

0%

3%

1%

14%

2%

Table 9: Probability of yield and collapse damage states based on degradation conditions at 2*MCE (0.72g PGA) Type of Frame

Mild

Moderate

Severe

Yield

Collapse

Yield

Collapse

Yield

Collapse

F1

98%

90%

96%

87%

100%

97%

F2

94%

70%

85%

60%

95%

87%

F3

70%

15%

58%

28%

75%

46%

5.2 Based on Web Portal Facility The Java Based Problem solving Environment (PSE) web portal facility is developed to enable

user to use High Performance Computers (HPC) and Grid Garuda Facility for IDA analysis using OpenSees (Fig. 5).

Fig. 5: Screen shots of PSE web portal facility 94â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


OpenSees is an Open-source system for geotechnical and earthquake engineering simulation system, IDA is carried out using OpenSees for RC frame and bridge structures using set of earthquake time history records. The output of OpenSees can be applied to

design various components of structure and to ensure its safety. OpenSees software framework system has been installed on workstation Param Padma and Param Yuva of C-DACâ&#x20AC;&#x2122;s HPC system sequentially as well as parallelly (Fig. 6).

Fig. 6: Screen shot of Garuda job submission portal facility for OpenSees

User can submit their RC structure simulation job using IDA technique through the job submission

facility and having the option to select the HPC system and version of OpenSees (Fig. 7).

Fig. 7: Screen shots of Job submission through PSE web portal

Since OpenSees is also available on all HPC clusters of Grid Garuda, users can submit their jobs related with earthquake engineering

The Bridge and Structural Engineer

simulations and get the results at their local desktop system (Fig. 8).

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 95


Fig. 8: Screen shots of Job submission through Garuda web portal

User just has to create a login facility after getting approval from admin of C-DAC and submit their jobs on the web portal. After successfully running

96â&#x20AC;&#x192; Volume 44

Number 1

March 2014

their jobs on HPC facility users can get their result files at their local desktop system and can store data as well (Fig. 9).

The Bridge and Structural Engineer


Fig. 9: Screen shots of Results download facility

these frames show considerable damage with more than 60% probability of getting collapsed.

6. Conclusions Based on the performance of frames under various ground motion intensity levels and their evaluation with the help of fragility curves and also based on the usage of high performance computing facilities by developing web portal and providing a platform for the users to port their problems and thereby get their results at their own desktop, following inferences are drawn: F1 frames perform well in DBE (0.18g), however, these frames are likely to damage considerably with more than 30% probability of getting collapsed for MCE (0.36g). In case, when confinement level is kept low with severe degradation of strength and stiffness then these frames are likely to collapse with a probability of 58% in a scenario of MCE (0.36g). Also, chances of getting collapsed of these frames in a scenario of earthquake with 0.72g PGA (2*MCE) are more than 90%.

F3 frames show better performance not only at DBE (0.18g) but also at MCE (0.36g) scenario. These are undamaged at DBE (0.18g) and show minor damage at MCE (0.36g) occurrences.The probability of damage in collapse with severe degradation of these frames is well below as compared to other frames at MCE (0.36g). Apart from this, the probability of getting collapsed of these frames at 2*MCE scenario is 15% to 28% and in severe degradation these frames shows 46% probability of collapse which is well below from F1 and F2 frames.

l

l

F2 frames are likely to get damaged with more than 20% probability of yielding and 5% to 10% probability of collapse for MCE (0.36g). Also in severe degradation these frames show lesser damage than that in F1 frames at MCE (0.36g). At 2*MCE scenario,

l

The Bridge and Structural Engineer

From the results it is concluded that by adopting capacity design principles, buildings perform well at higher intensity ground motions. Also, if column sections are designed using capacity design concept in flexure with incorporating the contributions from floor reinforcement to beams, the frames performs well even at 0.72g PGA scenario without increasing the total cost of the project significantly.

l

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 97


The TCL scripting is developed for RC Frame analysis of structures for IDA on HPC for OpenSees using SI system of units and it worked very fine on Param Yuva facility of C-DAC. Moreover, users can refer these scripts to generate their own scripts for their desired frames.

of 3D RC Frame Designed for Damage Avoidance”, Earthquake Engineering and Structural Dynamics, Vol. 37, No. 1, 2008, pp. 1-20.

l

The sequential and parallel version of OpenSees is ported through C-DAC’s HPC and Grid Garuda facility and working successfully to simulate the RC structures for ID analysis. The web portal is having facility to directly add reviews, comments and questions regarding the usage facility and also one can put the feedback after using the portal facility. The web based portal facility will be the benchmark activity for Indian structural and earthquake engineering researchers and consultants to carry large scale simulations of civil engineering structures on HPC facilities.

4.

DHAKAL R. P., MANDER J. B., and LI L., “Identification of Critical Ground Motions for Seismic Performance Assessment of Structures”, Earthquake Engineering and Structural Dynamics, Vol. 35, No. 8, 2006, pp. 989-1008.

5.

DHAKAL R. P., SINGH S., and MANDER J. B., “Effectiveness of Earthquake Selection and Scaling Method in New Zealand”, Bulletin of the New Zealand Society for Earthquake Engineering, Vol. 40, No. 3, 2007, pp. 160-171.

6.

IS: 13920, “Indian Standard Code of Practice for Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces”, Indian Standards Institution, New Delhi, 1993.

7.

IS: 1893, “Indian Standard Criteria for Earthquake Resistant Design of Structures, Part 1-General provisions and buildings”, Indian Standards Institution, New Delhi, 2002.

8.

IS: 456, “Indian Standard Code of Practice for Plain and Reinforced Concrete for General Building Construction”, Indian Standards Institution, New Delhi, 2000.

9.

MAHONEY M., “The Japan Earthquake & Tsunami and What They Mean for the U.S.”, a report for FEMA, National Tsunami Hazard Mitigation Program, 2011, (NTHMP).

l

7. Acknowledgement Authors are thankful to Department of Science and Technology (DST), New Delhi, India for funding this research vide their sanction order no. SR/S3/MERC-001/2010. Thanks are also due to Directors, Shri Govindram Seksaria Institute of Technology and Science (SGSITS), Indore, India and Centre for Development of Advanced Computing (C-DAC), Pune , India for providing all necessary facilities in conducting this research.

8. References 1.

2.

3.

ACI 318-08, American concrete institute standard building code requirements for structural concrete and commentary, reported by ACI committee 318. BOTHARA J. K., MANDER J. B., DHAKAL R. P., KHARE R. K., and MANIYAR M. M., “Seismic Performance and Financial Risk of Masonry House”, ISET Journal of Earthquake Technology, Vol. 44, No. 3-4, 2007, pp. 421-444. BRADLEY B. A., DHAKAL R. P., MANDER J. B., and LI L., “Experimental MultiLevel Seismic Performance Assessment

98  Volume 44

Number 1

March 2014

10. MANDER J. B., DHAKAL R. P., MASHIKO N., and SOLBERG K. M., “Incremental Dynamic Analysis Applied to Seismic Financial Risk Assessment of Bridges”, Engineering Structures, Vol. 29, No. 10, 2007, pp. 2662-2672. 11. MANIYAR M. M., and KHARE R. K., “Seismic Vulnerability of Existing NonSeismic Reinforced Concrete Framed Buildings”, Indian Concrete Journal, Vol. 82, No. 4, 2008, pp. 27-35. The Bridge and Structural Engineer


12. MANIYAR M. M., KHARE R. K., and DHAKAL R. P., “Probabilistic Seismic Performance Evaluation of Non-Seismic RC Frame Buildings”, Structural Engineering and Mechanics, Vol. 33, No. 6, 2009, pp. 22. 13. SIVASELVAN M. V., and REINHORN A. M., “Hysteretic Models for Cyclic Behavior of Deteriorating Inelastic Structures”, Tech. Rep. MCEER-99-0018, Multidisciplinary Ctr. for Earthquake Engrg. Res., State University of New York at Buffalo, N.Y., 1999. 14. SOLBERG K. M., DHAKAL R. P., MANDER J. B., and BRADLEY B. A., “Rapid Expected Annual loss Estimation Methodology for Structures”, Earthquake Engineering and Structural Dynamics, Vol. 37, No. 1, 2008, pp. 81-101. 15. VAMVATSIKOS D., and CORNELL C. A., “Incremental Dynamic Analysis”, Earthquake Engineering and Structural Dynamics, Vol. 31, No. 3, 2002, pp. 491–514.

Appendix

ii)

Frame2D.analyze.Dynamic.EQ.bidirect. tcl: This file is used to apply ground motions to the model. We have applied the Bidirectional Earthquake so as to get the specific response. Here only we specify the time for which the simulation is given and ground motion scaling factors applied to the model.

iii)

BuildRCrectSection.tcl: In this script we have specified all details of the RC section such as no. of bars, bar diameter, cover etc.

iv)

LibAnalysisDynamicParameters.tcl: In this file we specify all the parameters required for the dynamic analysis.

v)

LibMaterialsRC.tcl: Properties of concrete and steel such as compressive strength of concrete etc are mentioned in this file.

vi)

LibUnitsSI.tcl: This file defines the system of units.

vii) ReadSMDFile.tcl: This file converts the ground motion records into the proper input format of OpenSees.

The TCL (Tool Command Language) scripts used in the analysis on OpenSees are listed as below:

viii) GMfiles.tcl: This folder contains ground motion histories of all earthquakes.

i)

ix)

GoAll.tcl: This file mentions the names of scripts that are run in the OpenSees application.

x)

OpenSees: The application in which the GoAll script is run so as to get the desired output.

Frame2D.build.InelasticFiberRCSection. tcl: The script used for building the model of the ten storied frame. Geometry, boundary conditions are specified in this file. Gravity loads, weights, masses are calculated and lateral loads are applied to the frame.

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  99


HIGH PERFORMANCE CEMENT CONCRETE SQUAT SHEAR WALLS UNDER REVERSE CYCLIC LOADING

N. Ganesan Professor of Civil Engineering, NIT Calicut, India ganesan@nitc.ac.in

P.V. Indira Professor of Civil Engineering, NIT Calicut, India indira@nitc.ac.in

P. Seena Ph D Scholar,Civil Engineering, NIT Calicut, India seenajiju17@gmail.com

Dr. N.Ganesan is a Professor of Civil Engineering at the National Institute of Technology, Calicut, India. He received his M.E and Ph.D degree from I.I.Sc, Bangalore. He is a fellow of The Institution of Engineers, India and IFIC consultant. He was a visiting professor at the Asian Institute of Technology, Bangkok and King Khalid University, Kingdom of Saudi Arabia.

Dr. P.V Indira is a Professor of Civil Engineering at the National Institute of Technology, Calicut. She received her M.Tech from IIT Madras and Ph.D degree from University of Calicut. She is a member of The Institution of Engineers, India.

P. Seena received her B.E (Civil Engineering) from Mangalore University Karnataka and M.Tech (Structural Engineering) from NIT Calicut. At present she is a Ph D scholar (QIP) in NIT Calicut, Kerala state.

Abstract: Behaviour of reinforced conventional concrete (CC) and reinforced high performance cement concrete (HPC) squat shear walls with aspect ratio one were investigated. The specimens were subjected to quasi static lateral reversed cyclic loading till failure. The high performance concrete (HPC) used was obtained based on the guidelines given in ACI 211.1 which was further modified by Aitcin. The longitudinal and transverse reinforcement ratios used in this study was 0.505%. The performance based parameters such as strength, stiffness degradation and energy dissipation capacity were obtained and the results are presented. Keywords: High performance concrete, Reverse cyclic load, Stiffness degradation, Squat shear wall, Ultimate load, Web reinforcement ratio.

1. Introduction The use of HPC in the construction of earthquakeresistant structures, long-span bridges, off-shore 100â&#x20AC;&#x192; Volume 44

Number 1

March 2014

structures, nuclear power plants, and other mega-structures generally result in the reduction in size and hence leads to lighter cost-effective structures. This brand of concrete has enhanced compressive strength, stiffness and durability. Other characteristics include almost no pasteaggregate transition zone, higher modulus of elasticity, very low permeability, exceptional abrasion resistance, outstanding resistance to freeze-thaw cycles, very low creep and high flexural strength [1]. Shear walls are commonly used to resist the actions imposed on buildings due to earthquake ground motions. Shear walls are efficient, in minimizing earthquake damage in structural and non structural elements in a building. Shear walls can also be an effective solution to rehabilitate moderately damaged existing structures. Most commonly used shear walls are symmetrical sections like rectangular and barbell shaped. Flanged shear walls are asymmetrical wall sections which are also often used. One of the The Bridge and Structural Engineer


most common classifications of shear walls is with respect to their overall height-to-length ratio known as aspect ratio. Squat shear walls are defined as walls with an aspect ratio smaller than or equal to one. The mode of deformation in this type of wall is dominated by shear. The main application of squat shear walls are in residential buildings, parking structures, industrial buildings, nuclear power plants, and also in highway overpasses and bridge abutments. The types of failures observed in squat shear walls, subjected to lateral loading are diagonal tension failure, diagonal compression failure (or web crushing and/or splitting failure), and sliding shear failure at the base of the wall. Review of literature indicates that several studies were conducted experimentally and analytically in the past to study the strength and behavior of normal concrete squat shear walls [2-12]. The major aim of these experimental investigations is to study the influence of various parameters such as aspect ratio of wall, shape, axial load ratio, shear stress demand, horizontal and vertical reinforcement ratio, and compressive strength of concrete on the behaviour of shear walls. However,only limited information is available on the strength and behaviour of reinforced high performance concrete (HPC) squat shear walls.Hence an experimental investigation was undertaken to evaluate the strength and behaviour of HPC squat shear wall and compare the same with reinforced conventional concrete (CC) squat shear wall under reverse cyclic loading.

2. Experimental Programme The experimental programme consisted of casting and testing of two squat shear walls made up of CC (CCW) and HPC (HPCW) under quasi static lateral reversed cyclic loading. The percentage

of longitudinal and transverse reinforcement used for both the walls were 0.505. 2.1 Materials The materials consist of (i) Ordinary Portland Cement (OPC) of 53 Grade conforming to IS: 12269-1987 [13], (ii) fine aggregate conforming to grading zone III of IS: 383-1970 [14] and having a specific gravity of 2.52, and (iii) coarse aggregate of 12.5 mm maximum size and having specific gravity of 2.80. The supplementary cementitious materials used were fly ash and silica fume. Fly ash was obtained from Mettur Thermal Power Plant, Tamil Nadu which conforms to ASTM C 618 [15] and Silica fume from ELKEM India (P) Ltd., Navi Mumbai conforms to ASTMC 1240 [16].Super plasticizer (Conplast 430) was used a as chemical admixture. The reinforcing steel consisted of High Yield Strength Deformed bars (HYSD) of Fe 415 grade. The longitudinal and transverse reinforcement consists of 6 mm diameter HYSD bars in the form of rectangular grid and placed in two layers. The nominal dimension of the specimens, together with the details of reinforcement is shown in Fig.1. 2.2 Details of mix proportioning The HPC used in this study was proportioned to attain a compressive strength of 60MPa. Mix design of HPC was done based on the guidelines given in ACI 211.1 [17] modified by Aitcin [18]. The mixes were obtained by replacing 20 percent of binder mass by fly ash and 8 percent binder mass by silica fume. The water binder ratio considered was 0.29. Conventional concrete (CC) was designed for a characteristic compressive strength of M60 grade as as per ACI 211.4 [19]. The mix design sheet of HPC for M60 grade concrete is given in Table 1.

Table 1: Mix design sheet Material properties Aggregate

GSSD

%

Gc

%

wabs

wtot

wh = (wtot-wabs)

Cement

3.15

72

Coarse

2.8

0.82

0

-1.25

Fly Ash

2.4

20

Fine

2.52

0.90

0

-3.9

Silica fume

2.1

8

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 101


Superplasticiser Specific gravity

Solids dosage

Gsup

s(%)

kg

1.22

40

Vw = Vliq.×

Vsol = Vliq - Vw

1

1

1

11.6

23.77

17.4

6.37

Content kg/m3

Volume l/ m3

Msol = C ×

Materials

Water w/b

d 100

Vliq =

162

M sol ×100 s × Gsun

100 − s Gsup × 100

Dosage kg/m3

Water Compositon correction 1 m3 l/ m3

162

162

156.00

405

129.00

405

405

110

46.00

110

110

45

22.00

45

45

375.00

1048.00

+7

1041.00

240

605.00

+5

600.00

20

0

6.37

11.6

-17.4

23.77

760

2418

-5.4

= 0.29

Cement

(C)

Fly Ash Silica Fume

560

Coarse Aggregate

1048

Fine Aggregate Percentage Air

2

Superplasticiser

(d)

2.07

TOTAL

Gssd – specific gravity in saturated surface dry condition

w/b - water binder ratio

wtot - total water content of aggregate in %

C - total binder content

d - SP dosage as % of mass of solids.

s - total solid content of SP in %

Vsol - volume of solids in SP

Gsup. - sp. gravity of SP

2.3 Test Specimen The experimental work consists of casting and testing of two squat shear walls with an aspect ratio of one. The dimensions of walls were 700mm x700mm x 80mm. To provide fixity at the bottom, a base block of 100 mm wide 450 mm deep and 1300 mm long was constructed monolithically with the walls. The specimens were designed and detailed according to the seismic provisions of ACI 318-2008 [20] . The details of the specimens are summarised in Table 2.

Fig.1: Geometry and reinforcement details of shear wall specimens 102  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


2.4 Casting of specimens For the construction of wall specimens, a specially designed steel mould made up of 100 mm wide and 8 mm thick mild steel flats was used . The steel mould was fabricated in such a way that it could be easily dismantled and assembled for repetitive use. The steel mould was arranged so that the wall and its base block can be cast monolithically. The specimens were cast horizontally on a level floor in the Structural Engineering Laboratory. Required numbers of bolt holes of 50 mm diameter were also provided in the base block of the wall corresponding to the position of holes in foundation block. Figs.2a and 2b show the reinforcement cage placed in steel mould and specimens after casting. The form work was removed after 24 hours of casting and cured for 28 days. Table 2: Details of specimens Specimen Designation

Fig. 2b. Specimen after casting

Aspect ratio of shear wall ( H /L)

Longitudinal reinforcement ratio in web ρl(%)

Transeverse reinforcement ratio in web ρt(%)

CCW

1

0.505

0.505

HPCW

1

0.505

0.505

Fig. 2a: Reinforcement cage in steel mould

The Bridge and Structural Engineer

3. Test Set up and Instrumentation Double acting hydraulic jack of capacity 250 kN was used for applying lateral reverse cyclic loads. Linear variable displacement transducer (LVDT) having 300 mm travel and a least count of 0.01 mm was used for monitoring the in plane horizontal displacement at the top of the wall. Strain gauges of 120 Ω gauge resistance and 1mm gauge length were used to measure strains in the longitudinal and transverse bars of the walls. A data acquisition system was used for monitoring steel strains continuously. Figs. 3a and 3b show the schematic diagram and photograph of the test set up. A load cell of 250 kN capacity was used to measure the applied load accurately. Load cell readings were measured from a load indicator. The application of push and pull cyclic loading on the specimen was done using an arrangement consisting of mild steel rods with 25 mm diameter, threaded on both ends and connected to mild steel channels and fixed to the hydraulic jacks through load cells for the forward and reverse application of loads. Specimen was inserted into the foundation block and connected through the holes on the web portion of the foundation using 50 mm diameter mild steel rods.

Volume 44

Number 1

March 2014  103


were incrementally loaded with a hydraulic jack having capacity 250kN. One cycle of loading consisted of both forward and reverse cycles and after each cycle, the amplitude of loading was increased. This process was continued till lateral failure occurred. The loading history for the specimens consist series of stepwise increasing loading cycles as shown in Fig.4

4. Results and discussions 4.1 Overall Behaviour Both walls designed according to the seismic provisions of ACI 318-2008 exhibited a hysteretic behavior with shear failure. Details of test results are given in Table 3. It may be noted from the table that the first crack load of HPCW squat shear wall is 1.48 times higher than the CCW squat shear wall. The observed failure in these specimens were shear sliding. Fig.5 shows the Photograph of tested specimens.

Fig. 3a: Schematic diagram of the test set up

Fig.3b: Photograph of the test set up Fig. 4: Loading history

3.1 Testing of wall specimens The walls were subjected to quasi static lateral reversed cyclic loading till failure. The walls Table 3: Experimental results Specimen

First Crack Load (kN)

Ultimate Load (kN)

Displacement corresponding to Ultimate Load (mm)

Displacement at yielding of steel (mm)

CCW

10.1

86

14.50

9.23

HPCW

14.9

88

12.43

7.75

104â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


CCW

HPCW Fig. 5: Crack patterns of squat shear walls

4.2 Load deformation behaviour It was observed that the the lateral strength of both squat shear walls were almost same. It was also observed that HPCW exhibits less amount of lateral displacement than the CCW for the same type of loading, which indicates the increase in stiffness wall. The Load versus displacement envelope for the specimens are shown in Fig.6. It may be seen from these figures that load-displacement curves are linear up to the formation of first crack. After cracking, slope of the hysteresis curves (secant stiffness) degrades with increase of displacement.

[21-22]. The stiffness in a particular cycle was calculated from the slope of the line joining peak values of the base shear in each half cycle. Fig.7 shows the comparison of stiffness degradation for CCW and HPCW shear wall specimens. From the figure it may be noted that the initial stiffness of HPCW shear wall is higher than the CCW shear wall.

Fig.7 Comparison of stiffness degradation of squat shear walls

4.4 Energy Dissipation Capacity

Fig. 6: Load versus displacement envelope of specimens

4.3 Stiffness Degradation The lateral stiffness of the shear wall specimens were calculated from the base shear required for causing unit deflection at the top of the wall The Bridge and Structural Engineer

In seismic design, inelastic ductile behavior is associated with energy dissipation upon load reversal, which is an essential mechanism to survive strong earthquakes. The energy dissipation capacity of a member under the load is equal to the work done in straining or deforming the structure up to the limit of useful deflection, that is, numerically equal to the area under the load-deflection curve [23-24].The energy Volume 44

Number 1

March 2014â&#x20AC;&#x192; 105


dissipation capacity during various load cycles was calculated from the sum of the area under the hysteretic loops. Fig.8 shows the cumulative energy dissipation capacity with loading cycle number of the specimens.

Concrete Structural Walls: Strength, Deformation Characteristics and Failure Mechanism”, ACI Structural Journal, Vol. 87, No. 1, 1990, pp. 23-31. 4.

SITTIPUNT C., and WOOD “Influence of Web Reinforcement Cyclic Response of Structural ACI Structural Journal, Vol. 92, 1995,pp.1-12.

5.

SALONIKIOS N.T., KAPPOS J. A., TEGOS A.I., and PENELIS G.G., “Cyclic Load Behavior of Low-Slenderness Reinforced Concrete Walls: Failure Modes, Strength and Deformation Analysis, and Design Implications”, ACI Structural Journal, Vol. 97, No. 1, 2000, pp. 132-142.

6.

CHRISTIAN GREIFENHAGEN., and PIERINO LESTUZZI., “Static cyclic tests on lightly reinforced concrete shear walls”, Engineering Structures journals, Volume 27, 2005, pp 1703– 1712.

7.

KUANG J.S., and HO Y.B.,“Seismic behavior and ductility of squat reinforced concrete shear walls with nonseismic detailing”, ACI Structural Journal, Vol. 105, No. 2, 2008, pp. 225-231.

8.

GULEC C.K., and WHITTAKER A.S., “Empirical equations for peak shear strength of low aspect ratio reinforced concrete walls”, ACI Structural Journal, Vol. 108, No. 1, 2011, pp. 80-89

9.

WHITE C.A., UNIVERSITY OF CALIFORNIA, BERKELY and STOJADINOVIC B., SWISS FEDERAL INSTITUTE OF TECHNOLOGY., “Hybrid simulation of the seismic response of squat reinforced concrete shear walls” ,ZUR 2012. from http://iitk.ac.in/nicee/wcee/article/wcef 2012-2551.pdf

Fig. 8: Comparison of cumulative energy dissipation capacity of squat shear walls

The cumulative energy dissipation capacity of the HPC squat shear wall is 10% higher than that of CCW squat shear wall.

5. Conclusions This investigation conclusion 1.

leads

to

the

following

The first crack load of HPCW squat shear wall is 1.48 times higher than the CCW squat shear wall.

2.

HPCW shear walls exhibit less stiffness degradation compared to CCWshear walls. The initial stiffness of HPCW shear wall is 16.67% higher than the CCW wall.

3.

The cumulative energy dissipation capacity of the HPCW squat shear wall is 10% higher than that of CCW squat shear wall.

References 1.

AITCIN P.C., “Developments in the application of high-performance concretes”, Construction and Building Materials, Vol. 9, No. 1, 1995, pp. 13-17.

2.

PAULEY T., PRIESTLEY,M.J.N., and SYNGE A.J., “Ductility in Earthquake Resisting Squat Shearwalls”, ACI Journal, Vol. 79, No. 26, 1982, pp. 257-269.

3.

LEFAS I.D., KOTSOVOS M.D., and AMBRASEYS N.N., “Behavior of Reinforced

106  Volume 44

Number 1

March 2014

S. L., on the Walls”, No. 6,

10. WHITE C.A., UNIVERSITY OF CALIFORNIA,BERKELY and STOJADINOVIC B., SWISS FEDERAL INSTITUTE OF TECHNOLOGY., “Hybrid simulation of the seismic response of squat reinforced concrete shear walls full book”,Pacific Earthquake Engineering research center, ZUR 2013 The Bridge and Structural Engineer


11. JULIAN C., and SERGIO M. A., S “Shear strength of reinforced concrete walls for seismic design of low-rise housing”, ACI Structural Journal, Vol. 110, No. 3, 2013, pp. 415-423. 12. KAUSHIK M., and ARVIND K.M., and MURTY C.V.R., “Lateral load behavior of squat RC structural walls”, ICJ Indian Concrete Journal, Vol. 88, No. 2, 2014. 13. IS12269-1987 (reaffirmed 2004), “Specification for 53 grade ordinary portland cement”, Bureau of Indian Standards, New Delhi. 14. IS 383-1970 (reaffirmed 2002), “Specification for coarse and fine aggregates from natural sources for concrete”, Bureau of Indian Standards, New Delhi. 15. ASTM C 618-03 American Society for Testing and Materials,“Standard test method for coal fly ash and raw or calcined natural pozzolan for use in Concrete”, 2003. 16. ASTM C 1240-05 American Society for Testing and Materials.,“Standard specification for silica fume used in cementitios mixtures”,2005. 17. ACI 211.1-91 (reapproved2009), “Standard practice for selecting proportions for normal, heavyweight, and mass concrete”, American Concrete Institute,Farmington Hill, Michigan,

19. ACI 211.4R-08 “Guide for Selecting Proportions for High-Strength Concrete With Portland Cement and Fly Ash”, American Concrete Institute, Detroit, Michigan. 20. ACI 318-08,“Building code requirements for reinforced concrete,”American Concrete Institute, Farmington Hill”, Michigan, 2008. 21. GANESAN N., INDIRA P.V., and SHYJU P.T “Effect of ferrocement wrapping system on strength and behavior of RC frames under reversed lateral cyclic loading”, International Journal  of  Experimental Techniques, 2010, Wiley-Blackwell Publications, pp.1-5. 22. DEVI G.N., SUBRAMANIAN K., and SANTHAKUMAR A.R., “Experimental investigations on reinforced concrete lateral load resisting systems under lateral loads”, International  Journal  of  Experimental Techniques, Wiley-Blackwell Publications,pp.59-73. 23. YUN-DO Y., CHANG-SIK C., and LIHYUNG L., “Earthquake performance of high-strength concrete structural walls with boundary elements”, International Proceedings of 13th World Conference on Earthquake Engineering, 2004. 24. KUANG J.S., and HO Y.B,“Seismic behaviour and ductility of squat reinforced concrete shear walls with nonseismic detailing”, ACI Structural Journal, 2008,105(2), pp.225-31.

18. AITCIN P.C., High Performance Concrete, London: U.K., E & FN Spon; 1998.

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  107


About ING - IABSE

About IABSE

The Indian National Group (ING) of the IABSE was set up in May 1957 under the patronage of the Government of India, Ministry of Road Transport and Highways and State Governments, as a non-official learned body with the participation of engineers and professional from both the public and private sectors as well as from various research and academic institutions. The Group organizes lectures, conferences, colloquia and workshops on topical subjects and publishes a quarterly technical journal “The Bridge and Structural Engineer.”

The International Association for Bridge and Structural Engineering (IABSE) was founded in 1929. Today, IABSE has about 4,000 members in over 100 countries. The mission of IABSE is to promote the exchange of knowledge and to advance the practice of structural and bridge engineering worldwide in the service of the profession and society. To accomplish the mission, IABSE organises conferences and publishes the quarterly journal “Structural Engineering International” (SEI), as well as reports and other monographs. IABSE also presents annual awards for outstanding achievements in research and practice that advance the profession of structural engineering. IABSE deals with all kinds of structures, materials and aspects of structural engineering.

108  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 109


110â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Indian National Group of the IABSE Office Bearers and Managing Committee members 2014 Chairman 1.

Shri VL Patankar, Director General (Road Development) & Special Secretary to the Govt of India, Ministry of Road Transport and Highways Vice-Chairmen

2.

Shri VK Gupta, Director General, Central Public Works Department

3.

Shri BN Singh, Member (Projects), National Highways Authority of India

4.

Dr Harshavardhan Subbarao, Member, Technical Committee of IABSE & Chairman and Managing Director, Construma Consultancy Pvt Ltd

5.

Shri Surjit Singh, Vice President IL&FS Engineering & Construction Co Ltd Past Chairmen

6.

7.

Shri C Kandasamy, Former Director General (Road Development) & Special Secretary Shri RP Indoria, Former Director General (Road Development) & Special Secretary Honorary Treasurer

8.

The Director General (Road Development) & Special Secretary to the Government of India Ministry of Road Transport and Highways Honorary Members

9.

Shri Ninan Koshi, Former Director General (Road Development) & Addl. Secretary

10. Prof SS Chakraborty, Past Vice-President, IABSE & Chairman, Consulting Engineering Services (India) Pvt Ltd Persons represented ING on the Executive Committee and Technical Committee of the IABSE 11. Dr BC Roy, Vice President, IABSE & Past Member, Technical Committee, IABSE, Senior Executive Director, JACOBS-CES The Bridge and Structural Engineer

12. Dr Harshavardhan Subbarao, Member, Technical Committee of IABSE & Chairman and Managing Director Construma Consultancy Pvt Ltd Past Member of the Executive Committee and Technical Committee of IABSE 13. Prof SS Chakraborty, Past Vice-President, IABSE & Chairman, Consulting Engineering Services (India) Pvt Ltd 14. Shri CR Alimchandani, Past Member, Technical Committee, IABSE & Chairman and Managing Director, STUP Consultants P Limited 15. Dr BC Roy, Vice President, IABSE & Past Member, Technical Committee, IABSE, Senior Executive Director JACOBS-CES Honorary Secretary 16. Shri RK Pandey, Secretary, ING-IABSE & Chief Engineer (Planning), Ministry of Road Transport and Highways Members of the Executive Committee 17. Shri Mahesh Kumar, Engineer-in-Chief, Govt of Haryana, Public Works (Buildings & Roads), Department 18. Shri NK Sinha, Former DG (RD) & Special Secretary 19. Shri G Sharan, Former Director General (Road Development) & Special Secretary 20. Shri AK Banerjee, (Technical), NHAI

Former

Member

21. Shri Alok Bhowmick, Managing Director, B&S Engineering Consultants Pvt Ltd 22. Shri AV Sinha, Former Director General (Road Development) & Special Secretary 23. Dr Nirmalya Bandyopadhyay, Director, STUP Consultants Pvt Ltd Secretariat 24. Shri RK Pandey, Secretary, ING-IABSE & Chief Engineer (Planning), Ministry of Road Transport and Highways Volume 44

Number 1

March 2014â&#x20AC;&#x192; 111


25. Shri Ashish Asati, Director, Indian National Group of the IABSE

26. Shri KB Sharma, Under Secretary, Indian National Group of the IABSE

Members of the Managing Committee–2014 Rule-9 (a): A representative of the Union Ministry of Road Transport and Highways 1.

Shri VL Patankar, Director General, (Road Development) & Special Secretary, Ministry of Road Transport & Highways

8.

Govt of Bihar - nomination awaited

9.

Govt of Chattisgarh - nomination awaited

10. Shri Dinesh Kumar, Engineer-in-Chief, Govt of Delhi 11. Govt of Goa - nomination awaited 12. Govt of Gujarat - nomination awaited

Rule-9 (b): A representative each of the Union Ministries / Central Government Departments making annual contribution towards the funds of the Indian National Group of IABSE as determined by the Executive Committee from time to time 2.

Shri VK Gupta, Director General, CPWD

3.

Shri BN Singh, Member (Projects), National Highways Authority of India

4.

Shri SK Agrawal, Executive Director, Civil Engineering (Bridges & Structures), Ministry of Railways

Rule-9 (c): A representative each of the State Public Works Departments/ Union Territories making annual contribution towards the funds of the Indian National Group of IABSE as determined by the Executive Committee from time to time 5.

Govt of Andhra Pradesh - nomination awaited

6.

Govt of Arunachal Pradesh - nomination awaited

7.

Shri AC Bordoloi Commissioner & Special Secretary to the Govt of Assam

112  Volume 44

Number 1

March 2014

13. Shri Mahesh Kumar, Engineer-in-Chief, Govt of Haryana 14. Govt of Himachal Pradesh - nomination awaited 15. Govt of Jammu & Kashmir - nomination awaited 16. Govt of Jharkhand - nomination awaited 17. Shri AN Thyagaraja, Chief Engineer, Communication & Buildings (South), Govt of Karnataka 18. Govt of Kerala - nomination awaited 19. Govt of Madhya Pradesh - nomination awaited 20. Shri EP Ugile, Chief Engineer, Govt of Maharashtra, 21. Shri Ram Muivah, Principal Secretary (Works), Govt of Manipur 22. Shri L Passah, Chief Engineer (NH), PWD (Roads), Govt of Meghalaya 23. Shri John Rammawia, Chief Engineer (Highways), Govt of Mizoram 24. Govt of Nagaland - nomination awaited 25. Govt of Orissa - nomination awaited 26. Govt of Punjab - nomination awaited 27. Govt of Sikkim - nomination awaited The Bridge and Structural Engineer


28. Govt of Tamil Nadu - nomination awaited 29. Govt of Tripura - nomination awaited 30. Govt of Uttar Pradesh - nomination awaited 31. Smt Nimmy Singh, Executive Engineer, Govt of Uttarakhand 32. Shri Debashish Roy, Suptd Engineer, BI Cell, Govt of West Bengal 33. Shri SK Chadha, Chief Engineer, Union Territory Chandigarh Rule-9 (d): A representative each of the Collective Members making annual contribution towards the funds of the Indian National Group of IABSE as determined by the Executive Committee from time to time 34. Major VC Verma, Director (Mktg), Oriental Structural Engineers Pvt Ltd Rule-9 (e): Ten representatives of Individual and Collective Members 35. Shri NK Sinha, Former DG (RD) & Special Secretary 36. Shri G Sharan, Former DG (RD) & Special Secretary

44. Dr Lakshmi Parameswaran, Chief Scientist, Bridges & Structures Div, CSIR-Central Road Research Institute 45. Dr Nirmalya Bandyopadhyay, Director, STUP Consultants Pvt Ltd 46. Shri RK Jaigopal, Consultant, Concrete Structural Forensic Consultant Rule-9 (f): Four representatives of Bridge and Structural Engineering Firms 47. Shri MV Jatkar, Executive (Technical), Gammon India Ltd

Director

48. Shri Sanjay Dave, General Manager – Engineering Management, Hindustan Construction Co Ltd 49. Vacant 50. Vacant Rule-9 (g): Two representatives of the Engineering Colleges / Technical Institutes / Universities / Research Institutes 51. Vacant 52. Vacant

Member

Rule-9 (h): Four representatives of Consulting Engineering Firms

38. Shri AV Sinha, Former DG (RD) & Special Secretary

53. Shri Dipankar Paul, Executive Director, Consulting Engineering Services (India) Pvt Ltd

39. Shri V Velayutham, Former DG (RD) & Special Secretary

54. Shri AD Narain , President, ICT Pvt Ltd

37. Shri AK Banerjee, (Technical), NHAI

Former

40. Shri Alok Bhowmick, Managing Director, B&S Engineering Consultants Pvt Ltd 41. Shri Surjit Singh, Vice President, IL&FS Engineering & Construction Co Ltd

55. Shri A Ghoshal, Director & Vice President, STUP Consultants Pvt Ltd 56. Dr GP Saha, Executive Director, Construma Consultancy Pvt Ltd

42. Shri Rakesh Kapoor, General Manager, Holtech Consulting Pvt Ltd

Rule-9 (i): Honorary Treasurer of the Indian National Group of the IABSE

43. Shri Inderjit Ghai, Chief Executive Officer, Consulting Engineers Associates

57. The Director General (Road Development) & Special Secretary to the Govt of India

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  113


Rule-9 (j): Past-Chairman of the Society, for a period of three years, after they vacate their Chairmanship

Rule-9 (m): Persons represented ING on the Executive Committee and Technical Committee of the IABSE

58. Shri RP Indoria

63. Dr BC Roy

59. Shri C Kandasamy

64. Dr Harshavardhan Subbarao

Rule-9 (k): Secretary of the Indian National Group of the IABSE

Rule-9 (n): Past Members of the Executive Committee and Technical Committee of the IABSE

60. Shri RK Pandey

65. Prof SS Chakraborty Rule-9 (l): Persons who have been awarded Honorary Membership of the Parent Body

66. Shri CR Alimchandani 67. Dr BC Roy

61. Shri Ninan Koshi 62. Prof SS Chakraborty

114â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


MINUTES OF THE MEETING OF THE 101st MANAGING COMMITTEE OF THE ING-IABSE HELD AT NEW DELHI ON THE 22ND MARCH 2014 members, who had co-operated in the timely review of all the papers from time to time. However, Shri Alok Bhowmick also emphasized that the present working model for publication of this journal is not sustainable and ING-IABSE must have a full time Editor on board, in order to maintain and sustain this quality. It is also necessary to continuously strive for sponsorship of the journal through advertisement, for which ING-IABSE secretariat has to work harder.

Present (list enclosed, Annexure-1) Members (list enclosed, Annexure-1) Invitees (list enclosed, Annexure-1) Item-1 Report of the activities of the Indian National Group of the IABSE for the period from 1st March 2013 to 31st January 2014 The Managing Committee approved the report of the activities of the Indian National Group of the IABSE for the period from 1st March 2013 to 31st January 2014 for placing before the 54th Annual General Body meeting to be held at New Delhi on the 22nd March 2014. However, while considering the report, the members suggested to take up the further action as follows. i)

Drive may be started to enroll more engineers as member of ING-IABSE. New Managing Committee members to take initiative in this regard.

ii)

New Managing Committee needs to meet more frequently (say quarterly) and take proactive steps for increasing the membership of ING-IABSE.

iii)

Dr Harshavardhan Subbarao pointed that he is a member of Working Group of IABSE and his name also be included in the report.

iv)

The Members who have discontinued INGIABSE membership may be approached again by the Managing Committee.

v)

The members appreciated for the fine works being done by the Editorial Board for uplifting the face of ING-IABSE Journal.

vi)

Shri Alok Bhowmick thanked the Managing Committee for this appreciation and mentioned that credit for this goes to the entire editorial board and advisory board

The Bridge and Structural Engineer

vii) ING-IABSE should have its own Website. ING-IABSE Secretariat to take necessary action in this regard. viii) Non Member Subscriber (NMS) of INGIABSE may be enhanced. IITs/technical Institutes may be approached. New Managing Committee members to take initiative in this regard. Item-2 Audit Report for the year 2012-2013 The Managing Committee approved the Audit Report for the financial year 2012-2013 for placing before the 54th Annual General Body meeting to be held at New Delhi on the 22nd March 2014. While discussing the audit report of ING-IABSE, members were of the view that amount kept for Building Fund may be utilized for the purpose. It was discussed by the members that ING-IABSE should have its own building/ floor/land and suggested that the following may be approached through Chairman of the Group in getting a suitable office premises for INGIABSE: 1)

The Director CPWD

General, Shri VK Gupta

2)

The Engineer Member, Shri Abhai Sinha DDA

3)

The Engineer-in-Chief, Delhi PWD

Shri Dinesh Kumar

Besides, it was also discussed that President of Indian Building Congress may also be pursued through Shri Mahesh Kumar, Engineer-in-Chief, Volume 44

Number 1

March 2014â&#x20AC;&#x192; 115


Haryana PWD for getting space for office in their RK Puram Building by paying construction value to IBC. Item-3 The Accounts for the financial year 2013-2014 together with Budget Estimate for the year 2014-2015

The Managing Committee approved the Budget Estimate of the Indian National Group of the IABSE for the year 2013-2014 and the Accounts for the financial year 2014-2015. The meeting ended with a Vote of Thanks to the Chair.

Annexure-1

101st Managing Committee Meeting held at New Delhi on 22nd March 2014 Present Shri Ninan Koshi

Past Chairman, ING-IABSE (Chaired the meeting on behalf of Chairman, ING-IABSE)

Shri Alok Bhowmick

Vice Chairman, ING-IABSE

Shri RK Pandey

Secretary, ING-IABSE

Members Shri AC Bordoloi

Shri AD Narain

Shri AK Banerjee

Shri AN Thyagaraja

Shri AV Sinha

Dr BC Roy

Shri BN Gupta (in place of GP Saha)

Shri CR Alimchandani

Shri G Sharan

Dr Harshavardhan Subbarao

Shri Mahesh Kumar

Dr N Bandyopadhyay

Shri Rakesh Kapoor

Shri RP Indoria

Invitees Shri Bageshwar Prasad

Dr BP Bagish

Shri Inderjit Ghai

Dr Lakshmy Parameswaran

Prof Mahesh Tandon

Shri NK Sinha

Shri RK Jaigopal

Shri Suresh Pal Singh

Shri Surjit Singh

Shri V Velayutham

116â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


MINUTES OF THE 54th ANNUAL GENERAL BODY MEETING OF THE ING-IABSE HELD AT NEW DELHI ON THE 22nd MARCH 2014 Present List of Members present in the meeting is at Annexure-1 In the absence of the Chairman, ING-IABSE, Shri Ninan Koshi, Former DG (RD) and Past Chairman of the Group chaired the meeting of the Annual General Body. Thereafter, the agenda items were introduced by Shri RK Pandey, Secretary, ING-IABASE, which were discussed and following decisions were taken. Item-1

Draft Report of activities of the Indian National Group of IABSE for the period from 1st March 2013 to 31st January 2014

The report of activities of the Indian National Group of the IABSE for the period from 1st March 2013 to 31st January 2014 as approved by the 101st Managing Committee in its meeting held at New Delhi on the 22nd March 2014, was approved. Item-2 Audit Report for the year 20122013 Rule-9 (e):

The Accounts of the Indian National Group of the IABSE for the financial year 2012-2013 was audited by M/s Pawan Khanna & Associates, Chartered Accountants, New Delhi. A copy of the Audited accounts as approved by the 101st Managing Committee in its meeting held at New Delhi on the 22nd March 2014, was approved. Item-3

To elect under Rule-9 (e), (f), (g) and (h) Members of the Managing Committee to hold office during 2014

All members were apprised by Secretary, INGIABSE that under Rule-9 (a), (b), (c) and (d) nomination of members of Managing Committee are made by Ministry of Road Transport and Highways, Union Ministries/Central Government Departments, State PWDs/Union Territories, Collective Members making Annual Contribution towards the funds of the Group. Elections were held under Rule-9 (e), (f), (g) and (h). The following were elected under these rules by the General Body.

Ten representatives of Individual Shri NK Sinha, President, ICT Pvt Ltd and Collective Members Shri G Sharan, Former DG(RD) & Spl Secretary Shri AK Banerjee, Former Member (Tech), NHAI Shri AV Sinha, Former DG(RD) & Spl Secretary Shri V Velayutham, Former DG(RD) & Spl Secretary Shri Alok Bhowmick, MD, B&S Engg Consultant Shri Surjit Singh, VP, IL&FS Engg & Const Co Ltd Shri Rakesh Kapoor, GM, Holtech Consulting Pvt Ltd Shri Inderjit Ghai, CEO, Consulting Engineers Associates Dr Lakshmy Parameswaran, Chief Scientist (Br), CRRI Co-opted (under Rule-12, b – Powers of the MC) Dr Nirmalya Bandyopadhyay, Director, STUP Consultants Shri RK Jaigopal, Consultant, CSFC

Rule-9(f):

Four representatives of Bridge Gammon India Ltd and Structural Engineering Firms Delhi Tourism & Tptn Dev Corp Hindustan Construction Co Ltd Larsen & Toubro Ltd IL&FS Engg & Construction Co Ltd

Rule-9(g):

Two representatives of Engineering Colleges/Technical Institutes/ Universities/Research Institutes

The Bridge and Structural Engineer

SERC Chennai Indian Railway Instt of Civil Engg, Pune

Volume 44

Number 1

March 2014  117


It was suggested by the committee that under Rule-9-(f) & (g) nominations may be called accordingly. Rule-9(h):

Four representatives of Consulting Engineering Shri Dipankar Paul, ED, CES (I) Ltd Firms Shri AD Narain, President, ICT Pvt Ltd Shri A Ghoshal, Director & VP, STUP Dr GP Saha, ED, CCPL

Members automatically elected on the Managing Committee under different rules are as under: Rule-9 (i):

Honorary Treasurer of the Indian National Group of Shri VL Patankar the IABSE

Rule-9 (j):

Past Chairman of the Society, for a period of threee Shri RP Indoria (2012 2013 & 2014) years, after they vacate their Chairmanship Shri C Kandasamy (2013, 2014 & 2015)

Rule-9 (k):

Secretary of the Indian National Group of the IABSE

Rule-9 (l):

Persons who have been awarded Membership of the IABSE (Parent Body)

Shri RK Pandey

Honorary Shri Ninan Koshi Prof SS Chakraborty

Rule-9 (m): Persons representing ING on the Executive Dr BC Roy Committee and Technical Committee of the IABSE Dr Harshavardhan Subbarao Rule-9 (n):

Item-4

Past members of the Executive Committee and Prof SS Chakraborty Technical Committee of the IABSE Shri CR Alimchandani Dr BC Roy

Any other business:

The Annual General Body during the discussions have also decided the following: (i)

The members were of the view that meetings of the Executive Committee of the ING-IABSE may be held at least every two months and Managing Committee quarterly in a year.

(ii)

The Group should expand activities by way of organizing Workshop/ Lecture in every quarter on topical subjects in different regions under the ageis of the ING-IABSE. Following regional groups were formed: 1.

Chandigarh Region

Shri Mahesh Kumar, E-in-C, Haryana Shri Inderjit Ghai, CEO, Consulting Engineers Associates

2.

Bangalore Region

Shri AN Thyagaraja, Chief Engineer, C&B (S) Govt of Karnataka, PWP & IWTD Shri RK Jaigopal, Consultant, CSFC

3.

NE Region (Assam) Region

Shri AC Bordoloi, Comm & Spl Secy, Assam PWD

4.

Mumbai Region

Shri CR Alimchandani, CMD, STUP Dr Harshavardhan Subbarao, CMD, CCPL

(iii) The members discussed in details the matter of service tax, it was suggested that opinion may be taken from service tax experts/consultant. (iv) The members of the Managing Committee authorized the secretariat to organize activities like workshops etc in different regions. The members of the Executive Committee may be informed through e-mail well before the time.

The meeting ended with a Vote of Thanks to the Chair.

118â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Annexure-1

54th Annual General Body Meeting held at New Delhi on 22nd March 2014 Present Shri Ninan Koshi

Past Chairman, ING-IABSE (Chaired the meeting on behalf of Chairman, INGIABSE)

Shri Alok Bhowmick

Vice Chairman, ING-IABSE

Shri RK Pandey

Secretary, ING-IABSE

Members Shri AC Bordoloi

Shri AD Narain

Shri AK Banerjee

Shri AN Thyagaraja

Shri AV Sinha

Shri Bageshwar Prasad

Shri BC Roy

Shri BN Gupta (in place of Dr GP Saha)

Dr BP Bagish

Shri CR Alimchandani

Shri G Sharan

Dr Harshavardhan Subbarao

Shri Inderjit Ghai

Dr Lakshmy Parameswaran

Shri Mahesh Kumar

Prof Mahesh Tandon

Dr N Bandyopadhyay

Shri NK Sinha

Shri Rakesh Kapoor

Shri RK Jaigopal

Shri RP Indoria

Shri Suresh Pal Singh

Shri Surjit Singh

Shri V Velayutham

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 119


REPORT OF THE ACTIVITIES OF THE INDIAN NATIONAL GROUP OF THE IABSE Activities:

General Report 2013

Period:

1st March 2013 to 31st January 2014

1. Committee Meetings Sl No.

Committee

Date

Place

Participants Number

Invitees Number

1.

EC

16.8.2013

New Delhi

12

-

2.

EC

10.9.2013

New Delhi

10

-

3.

EC

10.1.2014

New Delhi

12

01

4.

99th MC

6.4.2013

New Delhi

21

06

5.

53rd

AGB

6.4.2013

New Delhi

27

-

6.

100th MC

6.4.2013

New Delhi

23

04

2. Office-Bearers:

EC/MC/Secretariat

Executive Committee (EC)

Secretariat

VL Patankar

Chairman

RK Pandey

Hon Secretary

BN Singh

Vice Chairman

Ashish Asati

Hon Director

Alok Bhowmick

Vice Chairman

KB Sharma

Under Secretary

C Kandasamy

Past Chairman & Hon Treasurer

AV Sinha

Past Chairman

RP Indoria

Past Chairman

Ninan Koshi

Hon Member

Prof SS Chakraborty

Hon Member & Past Vice President of IABSE

Dr BC Roy

Vice President of IABSE & Past Member, Technical Committee of IABSE

Dr H Subbarao

Member, Technical Committee of IABSE

CR Alimchandani

Past Member, Technical Committee of IABSE

VK Gupta

Member

AD Narain

Member

AK Banerjee

Member

G Sharan

Member

SK Puri

Member

Nirmalya Bandyopadhyay

Member

RK Pandey

Hon Secretary

120â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Managing Committee

Representatives of:

Alimchandani CR

Bandyopadhyay Nirmalya

Central Public Works Department

Banerjee AK

Bhowmick Alok

Ministry of Railways

Bordoloi AC

Chadha SK

Chakraborty SS

Chakraparni RV

Dhiman RK

Ekambaram Raghuram

Govt of Arunachal Pradesh, PWD

Gangopadhyay Partha Ghoshal Amitabha

Govt of Chattisgarh, PWD Govt of Gujarat, PWD

Indoria RP

Jatkar MV

Kandasamy C

Kapoor Rakesh

Koshi Ninan

Kumar Bablu

Govt of J&K, PWD

Kumar Dinesh

Kumar Mahesh

Govt of Jharkhand, PWD

Muivah Ram

Narain AD

Pandey RK

Parsekhar UP

Passah Lambok

Patankar VL

Govt of Nagaland, PWD

Patel BP

Puri SK

Govt of Orissa, Works Department

Ramanjanelu K

Rammawia John

Rao G Jagannatha

Reddy M Thirpath

Roy BC

Saha GP

Sandhwar RR

Sharan G

Govt of Sikkim, PWD

Singh BN

Singh CK

Govt of Tamil Nadu, PW & P&IWTD

Sinha AV

Srinivasan T

Subbarao H

Tamsekar SB

Thyagaraja AN

Verma VC

Govt of Himachal Pradesh, PWD

Govt of Kerala, PWD

Govt of Rajasthan, PWD

Govt of Tripura, PWD Govt of Uttar Pradesh, PWD

Yadav VK

3.

Govt of Punjab, PWD

Govt of Uttarakhand, PWD

Indian Representation in the IABSE i)

Executive Committee

Dr BC Roy

ii)

Technical Committee

Dr Harshavardhan Subbarao

iii)

Permanent Committee : Delegates

Alternate Delegates

1.

Shri VL Patankar

Shri CR Alimchandani

2.

Prof SS Chakraborty

Shri VK Gupta

3.

Shri BN Singh

Dr Harshavardhan Subbarao

4.

Dr BC Roy

Shri G Sharan

iv)

IABSE Foundation

v)

Outstanding Structures Award Committee

Shri A Ghoshal

vi)

Member Working Group “Forensic Structural Engg”

Dr Harshavardhan Subbarao

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  121


At present, represented the members on the Working Commissions Sl. No

Name of Working Commissions

Member

Period

1.

Working Commission-I “Structural Performance, Safety and Analysis”

2.

Working Commission-II “Steel, Timber and Composite Structures”

Dr Nirmalya Bandyopadhyay

2011-2015

3.

Working Commission-III “Concrete Structures”

Shri SK Puri

2011-2015

4.

Working Commission-IV “Operation, Maintenance and Repair of Structures”

5.

Working Commission-V Processes”

6.

Working Commission-VI “Information Technology”

7.

Working Commission-VII “Sustainable Engineering”

“Design

Methods

and

Shri G Sharan

2011-2015

4. Indian Member of IABSE Membership Category 01

1st March 2013

Addn Nr. (1st Mar 2013 to 31st Jan 2014)

Less

78

2+3

01 - 21

Cat Change Add

Loss Nr. up to 31st Dec 2013

As on 31st Jan 2014 Total Nr

--

21

60

01 - FM 11

08

0+1

--

--

1

08

21

24

--

--

1

--

25

31 (HM)

01

--

--

--

--

01

FM-01

--

--

--

1

--

01

FM-21

04

--

--

--

1

03

03

47

6

--

--

8

45

Total:

162

12

2

2

31

143

01 11 21

Between 35 to 65 years Upto 35 years Above 65 years

122  Volume 44

Number 1

March 2014

31 FM 03

Honorary Member Fellow Member Collective Member

The Bridge and Structural Engineer


*Annexure-1

5. Annual Contribution A number of State Govts have not been paying annual contributions for several years. The position in detail of Annual Contribution are enclosed, Annexure-2. The defaulter States are being approached regularly with little response. The Executive Committee members may use their good offices in pursuing them to pay Annual Contribution in time.

6. Activities during the period i)

ii)

The Indian National Group of the IABSE hold its Annual Day-2013 along with a technical presentation on “Bridge Construction Challenges in Hilly Area” on 6th April 2013 at New Delhi. The Annual Day and presentation was attended by about 75 delegates, which was highly acclaimed. The Indian National Group of the IABSE organized one day “Workshop on “Movement of over Weight and Over Dimensional Consignment

The Bridge and Structural Engineer

(OWC/ODC)” at Patna and Bhopal in May 2013 and Hyderabad in July 2013. These Workshops were attended by about more than 100 delegates from various Govt Department as well as other private and public organizations. The Indian National Group of the IABSE successfully organized the 36th IABSE Symposium on “Long Span Bridges and Roofs – Development, Design and Implementation” at Kolkata from 24th to 27th September 2013. The IABSE Symposium 2013 was attended by more than 400 delegates from all over India and abroad, including some international experts as well as from Central/ State Government Departments, PSUs Private Sector Organisations and Academic Institutes.

7. Publication A quarterly Journal “The Bridge and Structural Engineer” is being published regularly. The same is now available online on website:http:// issuu.com/iabse.secretariat/docs/bse_ vol 43-3_ september2013_opt/1.

Volume 44

Number 1

March 2014  123


*Annexure-1 INDIVIDUAL MEMBERS WHO HAVE DISCONTINUED - 2013 Sl. No

Roll No

Name of Member

City

1.

541

A RAMAKRISHNA

2.

709

MV JATKAR

NAVI MUMBAI

1

3.

884

PERWEZ ALAM

MUMBAI

1

4.

898

JOGESH SINGH SONDHI

NEW DELHI

1

5.

906

ABHISHEK KUMAR

PATNA

11

6.

917

DHRUBAJYOTI BHATTACHARYA

KOLKATA

1

7.

935

LT GEN S RAVI SHANKAR, VSM

SECUNDERABAD

1

8.

950

T MAYILVAHANAN

MADURAI

1

9.

952

ASHOK KUMAR ADARSHA

SIROHI

1

10.

953

UK PANDEY

C/O 56 APO

1

11.

954

RS RAO

C/O 56 APO

1

12.

955

HARISH KUMAR

C/O 56 APO

1

13.

960

UPENDRA KUMAR

C/O 56 APO

1

14.

961

N HARIKRISHNA

C/O 99 APO

1

15.

962

SK PANDEY

C/O 99 APO

1

16.

963

AS RATHORE

C/O 99 APO

1

17.

965

RK AGRAWAL

SHIMLA

1

18.

966

RAJ KUMAR SHARMA

C/O 99 APO

1

19.

967

KISHOR CHANDWANI

GANDHINAGAR

1

20.

968

SUNIL KUMAR

C/O 99 APO

1

21.

969

SUNIL VERMA

C/O 56 APO

1

22.

970

GANESAN MUTHUKUMAR

PUNE

1

23.

974

YOGESH NAIR

C/O 56 APO

1

(EXPIRED)

1. Below 35 years (11)

- 1

2. Between 35-65 years (01)

- 21

3. Over 65 years (21)

- 0

4. Fellow Member (01)

- 1

CHENNAI

Cat 2013 21-FM

23

COLLECTIVE MEMBERS DISCONTINUED - 2013 1.

C110

GOVT OF TRIPURA

AGARTALA

3

2.

C182

SNC – LAVALIN INFRASTRUCTURE PVT LTD

NOIDA

3

3.

C204

GOVT OF UTTAR PRADESH

LUCKNOW

3

4.

C216

METAL ENGG & TREATMENT CO PVT LTD

KOLKATA

3

5.

C219

GOVT OF NAGALAND

NOIDA

3

6.

C225

SP SINGLA CONSTRUCTIONS PVT LTD

PANCHKULA

3

7.

C230

GOVT OF JHARKHAND

RANCHI

3

8.

C238

Cambridge Institute of Technology

RANCHI

3

124  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Annexure-2 STATEMENT OF THE ANNUAL CONTRIBUTION Sl Nr

Name of Annual Contributor

1.

Min of Road Highways

2.

Transport

&

Rate (Rs) (2013-2014)

Remarks

1,00,000/-

Up to date

Govt of Andhra Pradesh

60,000/-

Due for 2013-2014

3.

Govt of Arunachal Pradesh

60,000/-

Up to date

4.

Govt of Assam

60,000/-

Due for 2012-2013 & 2013-2014

5.

Govt of Bihar

60,000/-

Due for 2013-2014

6.

Govt of Goa

60,000/-

Due for 2011-2012, 2012-2013 & 2013-2014

7.

Govt of Gujarat

60,000/-

Due for 2012-2013 & 2013-2014

8.

Govt of Himachal Pradesh

60,000/-

Up to date

9.

Govt of Haryana

60,000/-

Due for 2012-2013 & 2013-2014

10.

Govt of Jammu & Kashmir

Paid partly up to 1988-89

Not paying since 1989-90

11.

Govt of Kerala

60,000/-

Due from 1997-98

12.

Govt of Karnataka

60,000/-

Up to date

13.

Govt of Maharashtra

60,000/-

Due for 2013-2014

14.

Govt of Manipur

60,000/-

Due for 2013-2014

15.

Govt of Mizoram

60,000/-

Up to date

16.

Govt of Madhya Pradesh

60,000/-

Up to date

17.

Govt of Meghalaya

60,000/-

Up to date

18.

Govt of Nagaland

60,000/-

Due for 2010-2011, 2011-2012, 2012-2013 & 2013-2014

19.

Govt of Orissa

Paying @ Rs 15,000/-

Due for 2013-2014

20.

Govt of Punjab

60,000/-

Due for 2013-2014

21.

Govt of Rajasthan

60000/-

Due from 1996-97

22.

Govt of Sikkim

60,000/-

Due from 2004-2005

23.

Govt of Tamil Nadu

60,000/-

Due for 2013-2014

24.

Govt of Tripura

60,000/-

Due for 2012-2013 & 2013-2014

25.

Govt of Uttar Pradesh

60,000/-

Due for 2010-2011, 2011-2012, 2012-2013 & 2013-2014

26.

Govt of West Bengal

60,000/-

Up to date

27.

Govt of Delhi

60,000/-

Due for 2013-2014

28.

UT Chandigarh

60,000/-

Due for 2012-2013 & 2013-2014

29.

National Highways Authority of India

60,000/-

Up to date

30.

Central Public Works Deptt

60,000/-

Due for 2013-2014

31.

Oriental Structural Engrs Ltd

60,000/-

Up to date

32.

Govt of Jharkhand

60,000/-

Due for 2011-2012, 2012-2013 & 2013-2014

33.

Govt of Uttarakhand

60,000/-

Up to date

34.

Ministry of Railways

60,000/-

Due for 2013-2014

35.

Govt of Chhattishgarh

60,000/-

Due for 2013-2014

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 125


126â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 127


128â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 129


130â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 131


132â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 133


134â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 135


136â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 137


MINUTES OF THE MEETING OF THE MANAGING COMMITTEE OF THE ING-IABSE HELD AT NEW DELHI ON THE 22nd MARCH 2014

102nd

Present List of Members and Invitees present in the meeting is at Annexure-1. In the absence of the Chairman, ING-IABSE, Shri Ninan Koshi, Former DG (RD) and Past Chairman of the Group chaired the meeting of the Managing Committee. Thereafter, the agenda items were introduced by Shri RK Pandey, Secretary, ING-IABASE, which were discussed and following decisions were taken. Item-1

Confirmation of the Minutes of the 101st Managing Committee of the Indian National Group of the IABSE held at New Delhi on the 22nd March 2014

The Minutes of the above mentioned meeting were confirmed by the members, is enclosed at Appendix-1. Item-2

Election of the Office-Bearers for the year 2014

Under Rule-10 of the Memorandum of Association, Rules and Regulations of the Indian National Group of the IABSE, the Managing Committee elected the following Office-Bearers: Chairman

Shri VL Patankar, DG (RD) & Spl Secretary, Ministry of Road Transport & Highways

Four Vice-Chairmen

Shri VK Gupta, DG,CPWD Shri BN Singh, Member (Projects), NHAI Dr Harshavardhan Subbarao, CMD, CCPL *Shri Surjit Singh, VP, IL&FS Engg & Const Co Ltd (* subject to becoming a Collective Member)

Five Members of the Executive Committee

Shri Mahesh Kumar, E-in-C, Haryana PW (B&R) Shri NK Sinha, President, ICT Pvt Ltd Shri G Sharan, Former DG(RD) & SS Shri AK Banerjee, Former Member (Tech), NHAI Shri Alok Bhowmick, MD, B&S Engg Consultants

The Executive Committee co-opted Shri AV Sinha, Former DG (RD) & Spl Secretary and Dr N Bandyopadhyay as member of the Executive Committee under Rule-20 “Power of the Executive Committee” as a special case. Other Members of the Executive Committee: Rule-9 (i):

Honorary Treasurer of the Indian National Group of Shri VL Patankar the IABSE

Rule-9 (j):

Past Chairman of the Society, for a period of three Shri RP Indoria (2012 2013 & 2014) years, after they vacate their Chairmanship Shri C Kandasamy (2013, 2014 & 2015)

Rule-9 (k):

Secretary of the Indian National Group of the IABSE Shri RK Pandey

Rule-9 (l):

Persons who have been awarded Membership of the IABSE (Parent Body)

Honorary Shri Ninan Koshi Prof SS Chakraborty

Rule-9 (m): Persons representing ING on the Executive Dr BC Roy Committee and Technical Committee of the IABSE. Dr Harshavardhan Subbarao

138  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


Rule-9 (n):

Past members of the Executive Committee and Prof SS Chakraborty Technical Committee of the IABSE. Shri CR Alimchandani Dr BC Roy

Rule-9 (o):

Past Secretary of the society for a period of two years after they vacate their Secretaryship.

Shri RK Pandey, Chief Engineer (Planning), Ministry of Road Transport and Highways to continue as Honorary Secretary and Shri Ashish

Asati, Superintending Engineer to continue as Honorary Director of the Group. The meeting ended with a Vote of Thanks to the Chair.

Annexure-1

102nd Managing Committee Meeting held at New Delhi on 22nd March 2014 Present Shri Ninan Koshi

Past Chairman, ING-IABSE (Chaired the meeting on behalf of Chairman, ING-IABSE)

Dr Harshavardhan Subbarao

Vice Chairman, ING-IABSE

Shri Surjit Singh

Vice Chairman, ING-IABSE

Shri RK Pandey

Secretary, ING-IABSE

Members Shri AC Bordoloi

Shri AD Narain

Shri AK Banerjee

Shri Alok Bhowmick

Shri AN Thyagaraja

Shri AV Sinha

Shri Bageshwar Prasad

Dr BC Roy

Shri BN Gupta (in place of GP Saha)

Shri CR Alimchandani

Shri G Sharan

Shri Inderjit Ghai

Dr Lakshmy Parameswaran

Shri Mahesh Kumar

Dr N Bandyopadhyay

Shri NK Sinha

Shri Rakesh Kapoor

Shri RK Jaigopal

Shri RP Indoria

Shri V Velayutham

Invitees Dr BP Bagish

Prof Mahesh Tandon

Shri Suresh Pal Singh

The Bridge and Structural Engineer

Volume 44

Number 1

March 2014  139


140â&#x20AC;&#x192; Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


" " The Bridge and Structural Engineer

Volume 44

Number 1

March 2014â&#x20AC;&#x192; 141


INDIAN NATIONAL GROUP OF THE INTERNATIONAL ASSOCIATION FOR BRIDGE AND STRUCTURAL ENGINEERING

No.ING/IABSEForm C-Declaration on Election

I………….……..……………………………………… have been elected as an …………………………….Member of the ING/IABSE agree to be governed by the Rules and Regulations of the said Society, as they now stand or as they may hereafter be altered or added to according to law and I undertake to promote the objectivities and interests of the Society so far as lies in my power provided that whenever I shall signify in writing eight months in advance to the Secretary that I am desirous of withdrawing from the Society, I shall, after the payment of any arrears which may be due from me, be free from the above mentioned obligations.

Witness my hand this………………day of………………..2014

Signature Also please furnish the Information overleaf.

C:\Documents and Settings\a\Desktop\MembershipForm.doc

142  Volume 44

Number 1

March 2014

The Bridge and Structural Engineer


The Bridge & Structural Engineer  

Building Structures Volume 44, Number 1, March 2014

The Bridge & Structural Engineer  

Building Structures Volume 44, Number 1, March 2014