Trenchless technology and geotechnical sectors remain curiously oblivious to each other. Incredibly few in the trenchless sector appear to give much consideration to the ground within which they operate, while the geotechnical industry has - with a few exceptions - failed to address the needs of the trenchless community.
It is a missed opportunity for both groups and ultimately for the client bodies, especially the major utilities and road authorities. The often complex interaction between soil and installation in trenchless techniques - especially directional drilling, microtunnelling and pipebursting - is considerable, but rarely considered. The irony is that if geotechnics was properly integrated into trenchless technology solutions, the techniques would be more reliable and clients would be much more willing to use them.
James Thomson of trenchless technology consultancy Jason Consultants agrees. He says to succeed at trenchless technology, contractors need to understand both the equipment and geotechnics. Over the last 10 years Thomson, who has positioned his consultancy to work on unusual and difficult trenchless projects, has become increasingly convinced that the secret of trenchless work is the early integration of geotechnics into the design.
In particular, trenchless technology practitioners need to be able to relate geotechnical conditions to machine behaviour, he says. Geotechnical engineers have not been much help because the trenchless sector finds it difficult to translate geotechnical language into a practical trenchless context.
Change is on the horizon and some of the trenchless contractors are making efforts to get to grips with the ground. As Louise Howe of Chiltern Thrustbore says: 'It's not just a matter of getting the right tooling and equipment - if you don't pay attention to the ground it can defeat you.'