Stability Analysis of Prescribed Slip Surfaces Based on a Combination of the Equilibrium Equation and the Critical Unstable Condition

Abstract

Stability analysis of potential slip surfaces is one of the core steps of slope safety evaluation. In this study, a novel model was developed that considers the critical unstable condition that represents the limit equilibrium and displacement constraints along a prescribed slip surface. The stress distribution and the safety factor of the prescribed slip surface in the critical state can be obtained by directly solving the nonlinear equations formed by the model. By incorporating the finite-element stress analysis, the proposed model does not require interslice force assumptions as do the traditional limit-equilibrium methods and can consider the influence of stress perturbation from outside of the slip body on its stability. The numerical algorithm is also detailed in the article. In addition, an analysis of three examples is carried out to validate the effectiveness of the proposed model and to demonstrate its feature of fast convergence.