Geotechnics' specialist advice service offers site evaluations, contract documentation, investigation design, geotechnical project management, data interpretation, slope stability assessment and analysis, remedial works design and supervision, the geotechnical aspects of highways and railways and in related expert witness representation. The service is available from each of the company's offices.
The study of available (although often unpublished) records concerning a site, its reconnaissance and mapping by experienced geotechnical engineers or geoenvironmental specialists can provide significant data on which to base a preliminary assessment of its characteristics and suitability for the intended purpose.
Appraisal of sites can be made in this way, even before they are acquired and prior to commitment to any specific scheme. Contaminated and derelict land presents particular problems which can be highlighted at this stage. Such data is used for preliminary design and planning of the form and scope of further investigation.
Foundations and Ground Treatment
The value of data obtained about any site is in its application to the evaluation and design of the proposed development. Such interpretation is an iterative process, responding to changes in design or in available data to achieve more efficient or safe construction. Frequently this can lead to more cost-effective conventional design, but with the need to develop difficult, filled or derelict sites within or near to urban areas, special techniques of ground improvement, foundation construction or pile installation are required to solve the problems safely and economically.
A thorough knowledge of these techniques and what they can achieve is essential. Problems of structural deformation can result from many sources such as clay shrinkage, heave, landslip, mining subsidence or consolidation. Identification of the cause of the problem and design of remedial works requires the specialist geotechnical input which this specialist advice provides.
Highways, Railways and Slope Stability
Highways and railways interact closely with the ground through which or over which they pass. The design of stable embankments and cuttings requires an understanding of past geological processes as well as the assessment of soil parameters appropriate to design. Increasing costs of haulage and sensitivity to the environment demand that the greatest possible use is made of on-site or locally available materials.
Many road schemes require special drainage, ground improvement and bridge foundations to satisfy limits on land acquisition, performance requirements, cost limitations and programme constraints. The use of instrumentation and its integration into the design and construction programme is becoming increasingly necessary as part of the Observational Method, so the close involvement of a geotechnical engineer with the design team is essential.