An optimized DEM-SPH model for surge waves induced by riverside landslides

Riverside landslides can induce surge waves during the process of entering water. The landslide-induced surge wave is often regarded as a significant secondary disaster, as its impact region is likely to be even more remarkable than the landslide itself. Due to the large deformation of the soil landslide and water body during the evolution of surge waves, commonly adopted multi-phase flow models and mesh-based methods coupled with discrete element models have some limitations, such as weak accuracy, and simulation distortion with immature coupling algorithms. As a result, the pure meshless method of smoothed particle hydrodynamics (SPH) coupling discrete element methods (DEM) become promising. Modified from the traditional empirical formulae-based coupling algorithm, this study proposes a semi-resolved algorithm that effectively eliminates the particle distortion at the fluid-solid coupling interface. The proposed model demonstrates its superiority through a comparison of the pressure and porosity near the coupling interface. Furthermore, the optimized DEM-SPH model is applied to simulate landslide-induced surge waves, and the simulation results have also validated the accuracy of the model. This model is capable of accurately simulating the entire propagation process from landslide entry into water to the wave reaching the opposite shore, and therefore provides an effective tool for the prediction and mitigation of wave hazards caused by landslides.