Contribution à l’étude numérique des fondations des structures offshore

Abstract

Our research focuses on assessing the performance of shallow foundations in complex geotechnical environments, with particular attention to two configurations: strip footings embedded in non homogeneous clay under eccentric loading, and offshore foundations equipped with vertical skirts placed on sloped ground subjected to seismic actions. Through an elastoplastic analysis carried out using the OptumG2 software, this study identifies the failure mechanisms and soil–structure interactions under varying loading conditions. In the case of strip footings, soil heterogeneity was found to enhance the bearing capacity, whereas eccentric loads significantly reduce it, especially for shallow embedment ratios. The observed failure patterns are highly influenced by both the soil profile and the foundation geometry, providing valuable insights for the design of foundations in stratified soils. Furthermore, offshore skirted foundations demonstrated improved stability, particularly when installed on frictional sloped soils under seismic loading. Key parameters such as slope angle, skirt embedment depth, and the normalized distance from the slope crest were shown to have a strong impact on the seismic bearing capacity. The inclusion of vertical skirts effectively compensates for the destabilizing effects of steep slopes and dynamic loads. Overall, our research provides practical recommendations for the design of foundations under complex conditions and opens promising directions for future investigations involving three-dimensional environments and soil–water interaction under seismic excitation.