NO DIG DOWN UNDER 24th International Conference, Brisbane 2006 Report by EA (Bob) Swinton The Australasian Society of Trench less Technology celebrates 25 years of operation, under the banner of rhe International Society for T renchless Technology, and rh is international conference amacred 1020 delegates, half of rhem from overseas. The ope ning address was from Josephine Parker MBE, a promi nent civil enginee r from UK, honoured for her voluntary work in thi rd world countries. Ar rhe opening breakfast fu nction, she was deliberately light-hearted , bur she focused on an important theme, the dearth of engineers, fo r all aspects of civil engineering. (Her add ress had good ideas and will be pu blished in a later issue of Water). T h is conference covered not jusr the tech niques of horizontal directional dri1ling, pull-through of pressure pipes and cables, and pipe-jacki ng of sewers, but a wide spectrum of rhe 'underground' business, includ ing cond ition assessment, infiltration, asset management, rehabilitation and renewal of sewers, detectio n and mapping of underground services and sessions on alliance contracting, risk allocation an d insurance. Most of rhe presentations are now posted on the ASTT web-sire. Some selected papers are published in rhis issue of Water.
Horizontal Directional Drilling and Rehabilitation Naturally there were numbers of papers devoted to rhe technology, backed up by so m e massive exhib its in rhe exhibi tio n. Papers extended fro m case studies (such as rhe Hallam Bypass Sewer, Water, Novembe r 2006) ro high-tech guidance rechnology, such as rhe use of high precision optical gyroscopes. In a keynote speech Stephe n Loneragan, GM of Directional Drilling ar rhe Lucas G roup, reviewed future directions and world trends. A useful series of papers, mainly from exh ibitors, span ned various methods of pipe repair, CI PP, pipe bursting, co nnection of laterals, to spray re-lining of pressure pipes.
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170WN U~R UXJfo Condition Assessment A number of papers foc used on inspecti on strategy, so me citing case examples ranging from H ong Ko ng to the Ruh r. Bruce Hutton and Da niel Faccio of Brisbane Water exp lain ed how they are app lying the German asset management program, AQUAVERTMIN . They have broken down their tru nk sewers and reticulation into a num ber of cohorts based on the parameters of similar construction, flow co nditions, characrerisri cs of the sewage, ere. using previous experience wirh each cohort to pred ict risk of fa ilu re, th en adding in rhe likely conseq uences (eg, high costs of fail ure in a commercial zone) then using linear programming to prioritise CCTV inspections and rehabili tation programs. Robert Stei n, from Stein and Partners, Bochum, Germany, explained their software package which applies fuzzy logic to determine priorities for re newal or rehabilitation. Th e biggest difficulty is differe ntiating the risk between one major damage versus a series of minor damages. His package aims to quantify rhe STATUS of a sewer, by raking in al l rhe fac tors such as material , diameter, so il properties, load, depth of cover. Regrettably, rhe 20 years of CCTV inspecti on data available in a European context is, in his opinion, 20% fl awed because there has been no rigid code of reporting defects. Th e ma tter of a consistent reporting code fo r CCTV inspection has been caken up by WSAA, and David Cox outlined the 2006 upda te which has been posted on rheir web-sire. None-the-less, operator fatigue is still a major factor.
Journal of the Australian Water Association
Ian Vickridge, B&V, summarised his work on Hong Kong water ma in s, with 3000 km to be rehabilitated in 15 years. Remote Field Technology and Near Field T echnology were used to meas ure resid ual wall thickness in steel pipes. H e pointed our char factory-applied bitumen coating is usually satisfactory bur rhe hand coating fo llowing a weld can be suspect. A system which mi ght operate in an operating main is under trial, rhe difficulty being char rhe fi rst trial reported no defects! A paper from Luisiana Tech reported on research on pulsed ground penetrating radar from a robot tracking inside nonconductive pipes. The pulse is only 0.2 picoseconds, and the reflected waves are analysed by the software to give both wa ll thickness an d presence of voids.
Asset Management The theme of cond ition assess ment was continued into discussions on asset management (A/M). If assets are supposed to have a 100 year life, then we should be replacing at least I% per year, but most auth orities do only a fracti on of that. Some com ments: W hat hi storical records have we gor to calibrate predictive models? South Africa laid an experi mental sewer which was dug up in ten years to assess rhe performance of materials. Vic EPA apply cri minal proceedi ngs if due diligence is not followed, bur how can lawyers assess this? A useful tool to pin point weak sewers is Ill , bur unforrnn arely with rhe drought, there hasn't been enough rainfall to do the analys is. So much industry re-organisation has happened rhar there are few engineers left with corporate knowledge. H istory is so viral that WSAA and Global Water Research Coalition are scarring a project bur they are enco untering reluctance to share data . Warre n Adams (MWH) reviewed global tre nds in A/M, com paring USA, UK, NZ, Australia. So far, Australians are world leaders, but USA is experienci ng an explosive growth, with mass ive investment in data analysis, modell ing and decision support.