SLOPE FAILURE MODES AT LARGE DEFORMATION IN SPATIALLY VARIABLE SOILS

Slope failure is often a large-deformation process of soils consisting of initiation, run-out and deposition stages. The deformation process determines the landslide consequence. Conventional slope stability analysis approaches such as Limit Equilibrium Method and Finite Element Method may face difficulties in modeling the whole process of slope failure, especially the post-failure process with large deformation of soils. Slope failure is controlled by uncertainties, and one important uncertainty is the spatial variability of soil properties. This study aims to investigate the evolution of slope failure modes at large deformation in spatially variable soils using Random Limit Equilibrium and Material Point Methods. Different types of failure modes are identified from different spatial distributions of undrained shear strength. Results reveal the spatial distribution of soil properties plays a significant role in the evolution of slope failure mode. It is of importance to characterize the in-situ soil properties for slope risk assessment and mitigation.