Subaerial rigid landslide-tsunamis: Insights from a block DEM-SPH model

In this paper, we substitute the solid particles in Tan and Chen [35] with blocks and propose a block DEM-SPH model aimed to study rigid landslide and its generated waves. Moreover, in addition to the buoyant and drag forces to account for landslide-water interaction, a virtual mass force is also incorporated. In this model, rigid slide motion is modeled by block DEM and tsunami waves are modeled by SPH. The blocks in DEM are resolved based on a multi-sphere approach and the novelty is that the discs attached to the block serve as DEM particles for contact force as well as SPH particles for repulsion force. For validation, block DEM is validated against the analytical solution and parametric sensitivity analyses are also conducted to test the model response on varied parameters. SPH is validated against the solitary wave experiment. Finally, the block DEM-SPH model is used to replicate the experiments of Heinrich [13] and Heller et al. [14]. Both slide kinematics and wave profiles can be reasonably reproduced if the drag and added mass coefficients (along with block friction angle) are properly selected. Some of these experiments were not well simulated in the past, particularly the rigid slide motion.