Probabilistic assessment of bearing capacity of skirted foundation under combined loadings with a rigid base

Abstract

Skirted foundations are critical components in offshore applications where combined loads are common in deep‐water environments. Their ultimate capacity under VH (vertical‐horizontal) combined loading is traditionally determined using VH failure envelopes, which are primarily constructed using numerical methods. These methodologies, however, frequently ignore the spatial variability inherent in seabed soils due to geological formations. This paper investigates the effect of spatial variability of undrained shear strength and embedment ratio impact on the capacity of skirted foundations subjected to VH combined loading. For this, OptumG2 software is used to perform Monte Carlo simulation combined with random finite element limit analysis. The present study investigates the stochastic bearing capacity and failure envelopes, with a particular emphasis on the influence of spatial correlation of undrained shear strength. The horizontal scale of fluctuation and the soil strength heterogeneity index are considered in this study. New results show the effect of a rigid base on VH failure envelopes and the evaluation of the vertical bearing capacity of skirted foundations.