Presentation of Critical Failure Surface of Slopes Based on the Finite Element Technique

摘要

Classical limit equilibrium analysis involves searching for the factor of safety and its associated critical slip surface. To date, most studies that have utilized the finite element (FE) method for slope stability analysis have focused on finding the critical factor of safety (F_s) that is in good agreement with the results from limit equilibrium (LE) analysis. Few studies have been performed to identify the critical failure surface(s) that result from FE analyses, as historically the F_s appears to have been the primary point of interest. When performing finite element analyses of a slope at its limit equilibrium state, it has been observed that there is a plastic shear zone which forms in the slope, extending from the toe to the top. This paper introduces an analogy of physical significance between contours of plastic strains from FE analysis and the LE safety map, which can be used to identify and visualize the critical failure surfaces of slopes. The validity of the proposed FE approach for the presentation of failure surface(s) is examined through numerical modeling of simple and complex geometries, and the results are compared to those from LE.