GIS Enabled SPH-Soil Modeling for the Post-Failure Flow of Landslides Under Seismic Loadings

Abstract

Landslide can usually be induced by a strong earthquake, and it causes very serious property damage and human casualties. Modeling of post-failure flow of landslides is one of the important approaches that can be used to simulate landslide flow developments and predict the landslide hazard zone. In this paper, a Smoothed Particle Hydrodynamics (SPH) model based on the constitution of elastic-plastic constitutive mechanics for soil has been developed for simulating the behavior of a class of geo-materials under the seismic loadings. Our SPH-Soil model considers the plastic behavior of the materials, and hence it is very important for more accurate and realistic simulations of geo-materials of soil type. The implemented materials laws in the SPH-Soil code include classical elastic-plasticity with a linear elastic part, and different applicable yield surfaces with nonassociated flow rules. In order to apply this model to actual landslide modeling the Geographic Information System (GIS) is utilized to generate site-specific models. We have thus developed a C# code to generate the particles of a given landslide site, which produces realistic particle mass and actual complicated boundaries for the SPH-Soil model. With GIS enabled, complex topography and irregular boundary can be accurately and easily built up. Then the SPH-Soil code has been applied to the well-known Daguangbao landslide, which was triggered by Wenchuan earthquake in 2008. The topographies after failure were compared with that obtained from field collected data and good agreement was found.