Numerical analysis of lateral - Moment capacity of bucket foundations for offshore wind turbine in sand

This paper reports the lateral - moment bearing capacity of bucket foundations under lateral loading in sand. The Modified Mohr-Coulomb (MMC) model is adopted to capture the hardening - softening behaviour in medium dense and dense sands within a finite element (FE) modelling framework. The FE model performance is assessed against available field test data as well as analytical solutions showing a relatively good agreement. A series of parametric study is con-ducted to investigate the effects of bucket aspect ratio, bucket diameter, load eccentricity, vertical load and relative density of sand on the lateral -moment bearing capacity of the bucket. Com-parisons are drawn between the conventional Mohr-Coulomb (MC) model and the stress depen-dent MMC model highlighting the role of sand dilatancy in mobilising the lateral moment capacity. Based on the FE results, a simple stepwise calculation framework is proposed for two scenarios: (i) to predict the lateral -moment bearing capacity of the bucket if the bucket di-mensions are known, and (ii) to design the bucket dimensions for a known required bucket capacity.