Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

GroundEngineering

David Greenwood says that in the interests of clients we should consider technical essentials paramount and devise commercial relationships to suit.

Talking Point in the last issue of Ground Engineering illustrated the frustration of an instrumentation specialist bound to work within an inappropriate commercial framework. I have long believed that the commercial arrangements in common use in the construction industry are incompatible with best practice when dealing with the technical requirements imposed by the ground. In the interest of clients and practitioners we should consider technical essentials paramount and devise commercial relationships to suit.

Unlike manufactured engineering materials the ground is inconsistent in structure and behaviour, and its properties are difficult to ascertain at relevant scale or location. This puts the choice of ground engineering technique at some risk. Geotechnical processes to modify the ground are also sensitive to ground properties which exacerbates risk related to these uncertainties.

While observational approaches lessen these risks, they imply uncertainty and that the design concept probably will be modified in the course of construction despite planned changes to programme and cost. The effect on the client's perception of overall construction performance tends to be adverse.

The more esoteric the engineering technique, the more it lies in the domain of the specialist - consultant or contractor. Too often when major groundworks are contemplated, the current commercial hierarchy of client, engineer, general contractor and specialist subcontractor leaves control in the hands of a non-specialist engineer and contractor. Without overall geotechnical appraisal of the inter-dependence of differing subcontracted specialities there is a scope for technical disaster. Often the design must be evolved around a field process, and so necessarily becomes the province of the specialist contractor. Similarly, execution of those works requiring specialist plant or knowledge of application techniques is a contracting activity. Yet such works require authority to vary actions in response to observations. Geotechnical construction should be intimately associated with the overall design concepts throughout the works.

Present commercial relationships allow the specialist subcontractor only cursory knowledge of design concepts, usually without access to all considerations; and during execution, the specialist subcontractor is separated from the conceptual engineer, and has restricted authority for necessary variations. Furthermore, at tender stage, alternative proposals perceived and submitted by the subcontractor are often conceived with neither sufficient information nor time for study. These are received by the engineer late in the project programme and often rely, with misplaced confidence on protection of the contract to make good deficiencies in assumptions about the ground. The general contractor frequently discounts the offer knowing that there will be re-bidding when he has secured the main contract. The engineer may not be aware of all the reservations pertaining to the alternative. All this leads potentially to misconceptions, remedial action, delay, disputes and extra costs.

We thus require 1) geotechnical specialists to appraise geotechnical works. 2) specialist contractors commitment to conceptual designs, and 3) uninhibited continuous collaboration between those executing geotechnical works and those conceiving them.

With respect to (1) regulatory authorities in UK are beginning discussion of the possibility of licensing engineers, as in some European and American countries. The complexity of modern engineering disciplines suggests that licensing should be applied to a variety of individual specialisims, so that only a licensed geotechncial engineer could approve geotechnical works. Might it not be beneficial for such a system to apply here?

Regarding (2) one can only applaud the progress made post-Latham towards collaboration and team building on construction projects. For geotechnics this needs to progress much further to the point where either the specialist is incorporated into the design team and paid for his input, or, is part of a complete design and build package team from the start of the work. In either case the geotechnical specialist (contractor or consultant) would be part of the conceptual engineering team.

Regarding (3) it is unfortunate that the necessary contractual relationships are still encapsulated in the ICE and JCT Conditions of Contract, and are difficult to change. The ICE is currently considering whether its Minor Works Contract or the Short Contract version of the New Engineering Contract would be appropriate for ground investigation works. Let us hope that this consideration can be extended to include all geotechnical works and will allow the necessary flexibility of action which they require in operation. Neither is wholly satisfactory for geotechnical, nor for any observational works in which design and execution are inextricably mixed with investigations and concepts.

Thus groundworks should become much more closely integrated with the design team, and would tend to bridge between design and execution. If the changes to management and commercial relations were given effect there would be much improvement in holding programmes and costs for geotechnical works to the benefit of all.

David Greenwood spent 40 years with Cementation, latterly as a director of the ground engineering, piling and mining companies. He is now an associate of Geotechnical Consulting Group and a member of ICE Council and Ground Board.

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.