Chris Clayton argues that we are not thinking radically enough about the re-engineering of routine groundwork.
Most engineers would happily accept that the standardisation of the way we do things is not only a 'good thing', but is also essential to ensure that the client gets a quality product at a low price. But how realistic is this view, when applied to the field of geotechnical engineering?
Following Latham and the formation of Sir John Egan's task force, the push to reduce the cost of UK construction, and thus increase the competitiveness of our major industries, is a significant challenge for our geotechnical engineering community. We know (for example through TRL and National Audit Office studies) that a large part of the financial risk to civil engineering construction and building is associated with geotechnical hazards. Managing these risks by appropriate site investigation and good design, and dealing effectively with the inevitable surprises produced by unforeseen ground conditions during construction, must help increase the chances of delivering new infrastructure on time and to budget.
Focus on these issues will be helped by a new Partners in Technology project on 'Managing geotechnical risk - improving productivity in UK building and construction' shortly to be undertaken for the Department of the Environment, Transportation and the Regions, by a consortium led by our Institution of Civil Engineers. But while we may reduce cost overruns, this is unlikely routinely to deliver the 50% saving which Egan is seeking.
There are broadly two approaches we might adopt to achieve further reductions in the costs which are associated with the geotechnical components of construction. The first involves standardising our products, improving the management of the process, and driving costs down through competition. The second demands a radical rethink of what we do, the abandonment of many accepted procedures and approaches, and a paradigm leap to a new position based upon exploiting the UK's world-class research to bring fresh thinking to the challenges that ground conditions place before us.
Standardisation and the introduction of quality systems have brought many benefits. They are invaluable in providing a ready basis for competitive bidding, and can greatly help the flow of information between the increasing number of contributors to a project. But in geotechnical engineering there has been fierce competition and considerable standardisation for decades. Accompanying this is a general feeling that quality (for example of site investigations) has been compromised by prices that have reduced in real terms; that too many geotechnical hazards are not properly dealt with during design; and that technical advance has been slow.
Perhaps some of the problem with site investigations arises from the fact that many clients commission this type of work principally because the construction professionals they employ would feel open to claims of negligence if it were omitted. How much better it would be if they regarded site investigation and geotechnical engineering as a means by which they could optimise use of their sites, while finding effective low-risk solutions for in-ground construction. For this to happen, every part of the geotechnical process needs to be rethought, with a view to achieving reductions in cost and in the time required for design and construction, while improving the quality and reliability of the product.
If UK geotechnical practice is to contribute to the future success of the British construction industry, we must develop a free-thinking and innovative attitude to what we do. For building projects could we re-engineer the entire investigation and design process? Do we need lengthy site investigations and foundation design, or could this be done during construction, when much more ground is likely to available for inspection? As an example, the Universities of Lancaster and Surrey, working with Stent Foundations, are seeking funding from the Engineering and Physical Sciences Council, and the Construction as a Manufacturing Process programme, for a project that would use the instrumentation on CFA piling rigs, allowing piles to be designed 'on the fly' without prior ground investigation. If we carried these thoughts further, might we be able to use intelligent foundations that tested the ground themselves, and either flexible or smart structures that were able to respond to ground movements as they occurred, to eliminate much ground investigation and geotechnical design? Could we standardise on many of the components we use, or on the parameters for much of the ground we build upon?
Because the ground is variable it will always be full of surprises. Geotechnical engineering can never be treated as routine, but there must be ways by which we could deal much better with the repetitive design issues, leaving us free to exercise our skill in identifying hazards and avoiding them where possible, while making projects easier and cheaper to build.
Chris Clayton is professor of geotechnical engineering at the University of Surrey, and a director of independent geotechnical test house Surrey Geotechnical Consultants. He has published extensively on the behaviour of geomaterials, laboratory and insitu testing, and on tunnelling.