Bearing Capacity of Suction Bucket Foundations for Offshore Wind Turbines in Dense Sand

Suction bucket foundations for offshore wind turbines are usually subjected to a high arm lateral loading. The lateral bearing response of suction bucket foundations in dense sand is explored through three-dimensional finite element numerical analyses. The Mohr-Coulomb elaso-plastic constitutive model in ABAQUS is improved by redevelopment through user subroutine interface, so that the pressure dependence of modulus of sand with the variation of average principal stress can be modeled. The finite element model is validated against published loading test in situ of bucket foundation in Frederikshavn. The load-displacement curves obtained from numerical analyses agree well with those from the in situ tests. The effect of loading height of lateral load and aspect ratio of foundation is investigated through parametric studies, on the bearing capacity and failure mechanism of suction bucket foundation. The results show that the moment capacity with respect to the center of the bucket lid increased with the increasing loading height, however the moment calculated in respect of the center of the bucket bottom almost did not change with the loading height.Compared with the case of clayey soil, the curvature of failure locus of bucket foundation in the load plane composed of horizontal load and moment in dense sand is smaller.According to the numerical calculation results, the simplified distribution mode of earth pressure on bucket wall is introduced, and a limit equilibrium method is developed to predict lateral capacity of bucket foundations with diameter of 10m order of magnitude in dense sand. © 2021, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.