Stability analysis of landslides using BEM and variational inequality based contact model

Abstract

Since the stability of a landslide is mainly controlled by the strength properties of the slip band rather than the sliding body, naturally the boundary element method is an excellent tool for the stability analysis of the landslide, where the slip surface is regarded as a contact boundary between the sliding body and the slip bed. By casting the contact problem into a mixed variational inequality problem (MiVIP), the convergence in dealing with contact nonlinearity has been proved significantly improved. In this study, the strength reduction technique is applied to bring the slope to the limit equilibrium state. A so-called critical element on the slip surface is always fixed to maintain the convergence during the strength reduction. Based on the fact that the strength redundancy of the critical element vanishes at the limit equilibrium state, the method of bisection is designed to find out the factor of safety. A typical example and an engineering bank slope are analyzed to demonstrate the numerical properties of the proposed procedure.