Numerical modeling of landslide-generated impulse waves in mountain reservoirs using a coupled DEM-SPH method

Landslide-generated impulse waves (LGIWs) often cause enormous damage. This study proposes a two-way coupled discrete element method (DEM) and smoothed particle hydrodynamics (SPH) method to study the whole hazard chain of LGIWs in mountain reservoirs. In this method, a two-way coupling code is developed to connect the DEM program Particle Flow Code 3D (PFC3D) and the SPH code DualSPHysics for simulating landslide sliding and fluid motion. A series of discretization operations are conducted to transform the DEM balls into discrete balls composed of SPH particles, and the dynamic boundary condition method is used to calculate the interaction forces between fluid and solid phases. This work is validated through a comparative analysis with published physical model experiments. Using the proposed method, the LGIWs induced by the RS deposit in the RM reservoir is simulated. The processes of landslide motion, impulse waves generation, propagation, and running up on the dam are studied. The results show that the proposed method possesses the capability to simulate and predict the hazards of LGIWs. This article represents the first implementation of PFC3D within a coupled DEM-SPH framework to study LGIWs, and provides a valuable way for assessing the associated risks.