GEOTECHNICAL PROCEDURES IN ECONOMIC HIGHWAY DESIGN. SINO-BRITISH HIGHWAYS AND URBAN TRAFFIC CONFERENCE. PAPERS PRESENTED AT THE CONFERENCE HELD IN BEIJING 17TH-22ND NOVEMBER 1986

This paper presents geotechnical procedures for economic highway design, which have been developed from the basic structure required by the Department of Transport in the United Kingdom, and which have been used on several major road schemes in the United Kingdom and abroad. Adoption of a structured procedure, with well defined reporting requirements for the geotechnical input into a highways scheme, can provide considerable benefits at all stages of scheme preparation. The greatest benefit is usually initiated at the stage of the geotechnical desk study, which should distil all information gained from preliminary research and give the geotechnical implications and constraints for each route corridor option. Once a route corridor has been selected, a preliminary site investigation should be undertaken to confirm the findings of the desk study, to provide sufficient information to allow preliminary design to proceed, and to ensure the elimination of all geotechnical uncertainties with a substantial cost implication. The main site investigation should be undertaken to enable the detailed design to proceed; thus its primary tasks are to determine soil/rock parameters from in situ and laboratory testing and the detailed macrofabric of strata where this is important to road design. The preparation of a geotechnical brief for the residential engineer who will supervise construction is considered to be an essential requirement; an example of such a brief is given, together with an example of a feedback report. (TRRL)