Three-Dimensional Limit Equilibrium and Finite Element Analyses: A Comparison of Results

Abstract

A numerical comparison of predictions by a rigorous 3-D limit equilibrium analysis and a finite element method is presented. The finite element method was modified so that it can predict a factor of safety having the same definition as in limit equilibrium. Thus, a meaningful basis for comparison was formed. Comparisons were limited to vertical cuts and included a pseudo-static seismic force component. Safety factors and their associated slip surfaces, predicted by the finite element and limit equilibrium analyses, exhibited very good agreement. This is surprising since the two analyses are fundamentally different. This good agreement adds credibility to the results of either analysis. This is particularly important in 3-D since detailed empirical information for analysis validation is extremely limited.