Biaxial loading of offshore monopiles: Numerical modeling

In this study, finite-element (FE) modeling was used to examine the influence of biaxial lateral loading of a monopile foundation. Two different soil models were adopted to investigate the influence of state-dependent and anisotropic behavior of soil on monopile response. A series of analyses was carried out in which both cyclic and static lateral loads were applied to the pile. Results show that biaxial loading significantly influenced the pile-head load-displacement response in addition to the development of significant accumulated displacements and coexistent soil loosening and densification. Moreover, predictions determined using a state-independent soil model were shown to be significantly nonconservative; these findings have important implications for environmental loading of offshore monopiles.