BS 5930: The Role of Geomorphological and Geological Techniques in a Preliminary Site Investigation

The recommendations for the design of a site investigation presented in BS 5930 were not found to be suitable for an investigation recently undertaken for the proposed A35 Axminster Bypass. Due to the many alternative alignments initially under consideration an investigation of all routes, involving boreholes, was not regarded as cost-effective and a programme of trial pitting and geotechnical mapping was instigated. This approach provided sufficient information for outline designs to be prepared enabling relative cost comparisons to be made between the various options and a preferred alignment to be suggested. It is proposed that amendments be made to BS 5930 to encompass the design and execution of this type of first stage site investigation and in particular to provide guidelines on the use of geotechnical mapping as a standard technique of investigation.