Application of DDA to simulate characteristics of the Tsaoling landslide

This study simulates the kinematic behavior of sliding blocks of rock in the earthquake-induced Tsaoling landslide using seismic discontinuous deformation analysis (DDA). We assume sliding rocks are elastic blocks. Detailed joint shear strength parameters are set in DDA in a manner compatible with what is known about the Tsaoling landslide mechanisms. Landslide run-out distance, information from survivors, and the post-failure topography are used to constrain the computational results. Calculations demonstrate that sliding rocks from the ground surface decoupled from those near the basal shear surface during the landslide. Local residents survived because surficial rocks were never deeply buried during the landslide. Additionally, shear strength parameters of material in the deposition area strongly govern final deposit topography. Computational results correlate well with actual post-failure topography.

► Seismic DDA is used to simulate the post-failure behavior of the Tsaoling landslide.
► Time-dependent seismic displacements are input as displacement constraints in DDA.
► The friction angle at the deposition area governs the final deposition topography.
► Air-cushion effect controls the rocks stopped on the Tsaoling slope.