Site investigation procedures and risk analysis

The research described In this thesis examines site investigation (SI) management procedures and how these might be improved. The historical development of SI procedures is reviewed and comments made as to the adequacy of present practice. A questionnaire survey was conducted to discover present day SI procedures and seek opinions from different sections of the SI industry (clients, consultants and SI firms). The best and recommended procedures are reported and then integrated with quality assurance(QA) procedures to illustrate how SI management can be conducted in a quality system.Conclusions drawn from the questionnaire replies indicated that consultants have difficulty In communicating to their clients the financial benefits of SI. Project management techniques were researched to discover a means of demonstrating and illustrating the benefits of SI in a way that a client can understand. An existing project management computer program, CASPAR, was investigated. However, to use the CASPAR risk analysis function difficult subjective judgements had to be made on how confidence in SI data might effect the uncertainties In a geotechnical activity. To overcome this difficulty geotechnical risk analysis programs were written so that decisions on individual SI values could be used to calculate the overall uncertainties in a geotechnical activity. These uncertainties were then input to CASPAR to show the effect that varying amounts of site investigation have on the financial risks for a construction project. CASPAR was adapted so that the complex probability distributions developed by the geotechnical risk analysis programs could be used without simplification.This two stage technique was tested with theoretical geotechnical works and projects. The technique proved successful and was used for two case studies. The technique may be used to assist in the communication of how ground risks can effect a clients financial return from a project and to illustrate how adequate SI will reduce the financial risk to a project, so that a more efficient economic strategy can be planned.