Run-out of the 2015 Shenzhen landslide using the material point method with the softening model

Abstract

Sand and soil are comprised of large amounts of discrete particles, which may lead to a transition between solid and fluid-like states in large deformation problems. How to deal with the complex transitions between these states in granular media is the key to explaining the run-out of a landslide. The Shenzhen (China) landfill landslide exemplifies a type of large deformation demonstrating this transition between solid and fluid-like states. The soil in the landfill was mainly composed of completely decomposed granite (CDG). The landslide's run-out traveled in fluid-like fashion several hundred meters and caused casualties. In this paper, we use the material point method (MPM) based on the softening model and contact algorithm to analyze the run-out of the Shenzhen landfill landslide. MPM offers substantial advantages in numerical simulations of problems involving extra-large deformations. The latest research of landslide simulations is reviewed, and the fundamental principles of MPM are introduced in the first part of the paper. Then, the post-failure behavior of the large slope in the Shenzhen landfill is simulated with the generalized interpolation material point (GIMP) method with a softening model and a contact algorithm, respectively. The trend of the velocities and displacements of material points are calculated. Topographies of the post-failure landslide using different parameters are analyzed.