A New Approach for Slope Stability Analysis: Combining the limit equilibrium method and finite element method

A new approach is proposed which uses concepts of both the limit equilibrium method (LEM) and finite element method (FEM) to analyse slope stability. The main limitation of the LEM is that it can give an incorrect display of the initial stresses. The FEM is able to overcome this limitation, however, it uses the shear strength reduction method (SSRM) to determine the safety factor. This SSRM has its limitations as well. It’s a mathematical approach to obtain the factor of safety, without using the strength definitions given by advanced soil models. The proposed method is able to overcome the limitations of both LEM and FEM. It uses a genetic algorithm to search for the most critical slip surface and the safety factor is defined as the as the ratio of the total maximum available shear strength along the slip surface to the total mobilised shear stress. Multiple case studies are performed in this research and the genetic algorithm is able to find a reasonable critical slip surface and safety factor in every example. The proposed method has proven to give reliable results compared to other analysis methods: LEM, FEM and other optimisation methods proposed in literature