Investigation of slope failure mode evolution during large deformation in spatially variable soils by random limit equilibrium and material point methods

This study investigates the occurrence and evolution of various slope failure modes during large deformation in spatially variable soils using Monte Carlo simulation combined with Limit Equilibrium Method (LEM) and Material Point Method (MPM). The proposed method takes advantage of both methods, i.e., the computational efficiency of LEM and the MPM's capability of modeling the whole process of a landslide, particularly large deformation of soils after the landslide is initiated. The proposed method is illustrated through a two-layer cohesive soil slope. Four slope failure modes (i.e., shallow, intermediate, deep and progressive failure modes) are identified and characterized quantitatively. It is found that the evolution and consequences of these failure modes depend on spatial distribution of soil shear strength. This highlights the value of the site-specific spatial variability information obtained from site investigation.