Efficient Method for Calculating Slope Failure Risk Based on Element Failure Probability

Abstract

The finite element method (FEM) and the limit equilibrium method (LEM) are commonly used for calculating slope failure risk. However, the FEM needs to carry out post-processing to estimate slope sliding surface, while the LEM requires assumption of the shape and location of the sliding surface in advance. In this paper, an element failure risk method (EFR) for calculating soil slope failure risk is proposed based on element failure probability (EFP) acquired by plastic limit analysis. The proposed method does not require any assumptions about failure modes. Firstly, the non-common-node triangle element is used to discrete the slope then the random field is generated based on the Cholesky decomposition midpoint method. According to the reliability stochastic programming model and solution strategy, the external overload coefficient, bulk overload coefficient, slope stability coefficient and velocity field of the slope under each random field are obtained, according to which the failure of the element is judged and the failure risk of the slope is calculated. In order to verify the correctness of the proposed method, two classical slopes are systematically analyzed. The research shows that compared with the traditional slope failure risk analysis method, the greatest advantage of the proposed method is that it can capture all failure modes of the slope and greatly simplify the calculation of the slope failure consequences of each failure mode. An efficient upper bound method (UBM) parallel program is prepared, which greatly improves the calculation efficiency.