Risk Assessment for Geotechnical Solutions Offshore (Invited Lecture)

More and more frequently, it is required to quantify risk in practice. Statistics, reliability analysis and risk assessment are important tools to account for uncertainties and to assist the process of decision-making. After briefly reviewing concepts of uncertainties, reliability, safety and risk, the paper presents applications and approaches for offshore geotechnical practice. Methods for analysis of bearing capacity and settlement to couple statistical observations, e.g. from geological evidence of underwater slope instability, and computed failure probabilities are presented. The geotechnical profession needs to improve its understanding of geological risks and its ability to deal with them. Risk perception in society triggers discussion of acceptable risk level and public protection guidelines. The paper concludes that the profession can only gain by implementing in practice more systematically than before probabilistic and risk-based thinking and, where appropriate, risk-based methodology.