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Len Threadgold looks at Rethinking investigation - constructing the team

Sir John Egan's work on the construction task force in the late 1990s, and the publication Rethinking construction in 2001, stimulated innovative thinking about the way in which construction projects were managed. Establishment of teams and commitment of the team members to each other, to better communication and to an absence of the adversarial approach allied to a client driven focus on value was seen as essential.

Site investigation would benet from such a rethink. This vital and fundamental element is most successful when those doing it are part of the team, are involved at the earliest stages of a project and continue through to its completion, operating in an integral manner with the project designers.

SI should be an iterative process, the scale and complexity of which should relate to the stage of design reached and the demands which the design makes. This requires knowledge of the benets of available investigation technologies and a clear understanding of the logistics and timescales involved.

As a consequence of the way investigations are often commissioned, their signicance and value is implicitly overlooked since inadequate time is allowed. Too often the over optimism of those commissioning the investigation on what can be achieved by a given technique in the time allotted, let alone the practicalities of site access, leads to frustration and recrimination - a recipe for claims and delays. The blame for this is often laid at the feet of the investigation specialist.

An SI should be designed by a specialist with due regard to the current site conditions, its history and geology as well as the requirements of the proposed development and project time scales. Phasing investigation work normally provides best value but tight construction programmes often restrict this process. Proposing less work than others, in response to a request for an SI, or working within a client's inadequate budget may look initially attractive, but too simplistic a ground investigation may not allow adequate design of an appropriate range of foundation solutions such as piling and lead either to over design or to claims. Conversely, it can lead to piling when further work may show this unnecessary.

Some years ago, research revealed the cost of an SI averaged 0.21% of project cost. If 10% of the cost is the differential between the cheapest and next cheapest quotation for the investigation contract, then £2,100 is the conceptual cost saving by appointing those putting in the lowest price on a £10m project, often irrespective of the capability or capacity of the company and its staff.

Such a saving pales into insignicance in relation to other project costs.

Innovative thinking at this stage can save millions of pounds and months on the time to complete a project.

The capabilities, experience and commitment of the geotechnical and geoenvironmental investigation specialist are an essential part of the successful design team and they should be chosen on this basis at an early stage so that this often-untapped resource can be released to the industry. It is worth remembering that the costs and delays associated with tender document preparation, evaluation and appointment can be significant.

The Association of Geotechnical and Geoenvironmental Specialists (AGS) was set up to provide a voice and focus for this industry.

Its members have put an enormous amount of work into the production of guidance and standards to ensure best value and practice as well as into innovations such as the AGS Format for data transfer. The build up of close working relationships with those commissioning the work of such specialists is vital to the implementation and development of best practice and best value.

This is happening in many instances but I believe that the widespread adoption of this practice throughout the industry would lead to much greater improvement in the product than would be achieved by the development of better sampling techniques for example, although the latter may be a consequence of the former.

Len Threadgold is managing director and owner of Geotechnics as well as an AGS committee member.

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