DEM analysis on the soil deformation characteristics around monopile foundation under cyclic lateral load

In recent years, research on the soil convective motion around laterally-vibrating structures has gained increasing attention due to its influence on the long-term stability of the structure. In this paper, two-dimensional (2D) discrete element modelling (DEM) is introduced to reveal the soil migration pattern around a monopile foundation under two-way cyclic loading. The soil sample, with homogeneous particle distribution and uniform stress state, is first generated using the brick replicate method (BRM), and the input parameters are calibrated against indoor tests. The evolution of the global soil deformation pattern at different numbers of load cycles is first presented, which is consistent with reported experimental findings. Then characteristics of the subsidence zone and the convection zone are analyzed from both macro and particle scales. The soil stress state around the vibrating monopile is presented. Numerical findings in this study uncover the temporal evolution of soil deformation and stress state, which could shed some light on the control of soil subsidence problems for offshore wind turbine foundations.