Probabilistic Stability Analysis for Deep‐Water Foundation

Abstract

A probabilistic analysis of the foundation stability of a deep-water, gravity based platform on soft clay was carried out by means of a first-order reliability method. Uncertainties in loading and in soil strength were included, together with a model uncertainty associated with the applied equilibrium model used for assessment of the stability. The sources of uncertainty were studied through an analysis of the results of the probabilistic analysis. It is shown that a dominating part of the total uncertainty is formed by the uncertainty in the loading, primarily in terms of the uncertainty in the significant wave height in the extreme storm, and secondarily in terms of the inherent uncertainty in the maximum loading in the storm. These and other study findings are discussed.