Runout Modeling of Earthquake-Triggered Landslides with the Material Point Method

Earthquake-triggered landslides have significant socio-economic impacts, claiming the lives of a third of the casualties associated with earthquakes due to their catastrophic runout. To improve the risk assessment and to mitigate the consequences of landslides due to seismic shaking, it is crucial to predict the initial triggering of mobilized mass (i.e., failure initiation) and to estimate the kinematics and postfailure final runout. While extensive work has been done in the field of earthquake engineering to address the small-strain failure initiation, the prediction of the kinematics and the final runout of earthquake-induced landslides have been less explored because of the complexities to simulate the shaking ground motion and the landslide event in a unified numerical framework. This paper presents the material point method (MPM) as a tool that is capable of simulating the landslide triggering and the whole instability process until its final runout. The use of a kinematic boundary condition applied to the nodes and a moving mesh technique is proposed to improve the efficiency of the calculation. A laboratory shaking table experiment is used for reference, and the MPM numerical results are compared to other nonlinear dynamic numerical approaches. Finally, a parametric analysis is conducted to understand the failure mechanics and emphasize the importance to further investigate the behavior of partially saturated soils subjected to dynamic loading.