A Coupled Discrete Element and Depth-Averaged Model for Flow-Like Landslide Simulations

Flow-like landslides commonly happen in mountainous areas and may cause economic and human life losses in the impacted areas. Computer modelling has become an effective tool for landslide risk assessment and reduction. Models based on discrete element method (DEM) have been widely used for landslide prediction; however, this method is computationally too demanding for large-scale applications. Depth-averaged models (DAMs) have been widely reported for simulating run-out and deposition of flow-like landslides over large spatial domains due to its relatively higher computational efficiency. To combine the advantages of both types of modelling approaches, this work introduces a novel landslide model developed by coupling a DEM model with DAM for simulation of flow-like landslides, in which the DEM is employed in the landslide initiation area to better simulate the failure mechanism of slope, and the DAM is adopted in the landslide runout and deposition phase, where the landslide has developed into flow-like landslide with fluid-like behaviour. Finally, the new coupled model is validated against an experimental test case. Satisfactory results have been obtained, demonstrating that the coupled model is able to accurately capture the detailed dynamics of flow-like landslides.