Abstract
More than before, society and standards require "risk-informed" decision-making. The paper demonstrates the benefits of implementing reliability concepts in offshore geotechnical design. Reliability-based approaches will assist preparing engineering recommendations and decision-making. The paper gives an overview of basic concepts of reliability-based design, discusses the advances of hazard, risk and reliability in geotechnical engineering and illustrates their use with case studies from offshore practice. Risk and reliability evaluations can vary from simple statistical evaluations to full probabilistic modelling of the hazards and consequences for a single or a system of offshore installations. The examples include pipeline siting, jack-up mobile units, piled foundations and the reliability of code requirements. The paper discusses the strengths of the reliability-based approach and key issues such as tolerable and acceptable risk and the selection of characteristic value. The paper concludes that reliability-based approaches offer a useful complement to deterministic analyses, and enable analyzing complex situations with uncertainties in a systematic and more complete manner than deterministic analyses alone, both for design and for reevaluation. Managing geotechnical risks should today become a natural part of the engineer's work.
