Capacity assessment of offshore skirted foundations under HM combined loading using RFEM

Abstract

Skirted foundations are widely used in offshore applications to resist the large vertical-horizontal-moment (VHM) loads likely to occur in deep water. Their ultimate capacity under combined loading is usually based on VHM failure envelopes commonly constructed using numerical methods but ignoring the spatial variability of seabed soils. This paper investigates the influence of spatial variability of undrained soil shear strength and the embedment ratio on the capacity of skirted foundations under HM combined loading. For this, a random finite element method (RFEM) was employed to identify the probabilistic HM failure envelopes of skirted foundations. A sensitivity analysis of the stochastic bearing capacity and failure envelopes to the soil spatial correlation has highlighted the significant effect of vertical scale of fluctuation on the skirted foundation response, mainly for low values.