A Theoretical Calculation Method Based on Nonlinear Analysis of Offshore Rigid Monopile on Sandy Slopes under Combined Loading

This study proposes a nonlinear analytical method to predict the response of combined loaded offshore rigid monopiles near sandy slopes. Considering the slope effect, the method discusses the ultimate soil resistance before and behind the pile separately. The method assumes that the subgrade reaction modulus varies nonlinearly with relative density but linearly with depth. The equilibrium equation for the pile-soil system is obtained from the balance of forces and moments. By analyzing four mechanical models of rigid monopiles under combined loading and selecting three of them as the basis, a failure mode determination method is provided. The accuracy of this method is verified by comparing with indoor model test, 3D FEA model test and centrifugal test.