Numerical study of the bearing capacity of the hybrid skirted foundations in silty sand under combined loading

The evolution of offshore wind turbine (OWT) foundations has led to increased demands for enhanced loadbearing capabilities. Among the various solutions, the hybrid skirted foundation stands out for its notable resistance to lateral forces and rotational movement. This study employs numerical analysis to investigate the failure mechanisms and bearing capacities of hybrid skirted foundations in silty sand strata under combined vertical (V), lateral (H), and moment (M) loads, comparing the results with those from traditional bucket foundations. This study delves into the influence of the geometric dimensions of hybrid skirted foundations and the soil parameters of silty sand on their bearing capacity. A parameter study reveals that the hybrid skirted foundation exhibits exceptional lateral resistance, with the diameter of the upper mat significantly impacting failure mechanisms and bearing capacities. In silty sand, the moment bearing capacity of hybrid foundations shows a remarkable enhancement, increasing by 78% compared to that of traditional foundations. Furthermore, a preliminary computational framework is proposed to estimate the bearing performance of the hybrid skirted foundation in silty sand under combined loads.