Three-dimensional dynamic simulation of waves produced by landslides: An analysis of the Mogangling landslide caused by the Moxi earthquake in 1786

Surge waves generated by landslides can lead to catastrophic consequences, including severe economic losses and lose of life. This study invenstigates the surge waves induced by the Mogangling landslide triggered by the 1786 Moxi earthquake through a combination of numerical simulations and field surveys. A detailed field invenstigation was conducted to characterize the engineering geological features of the Mogangling landslide. Based on the point cloud data, a three-dimensional (3D) landslide model was constructed and used for numerical simulations. The landslide motion was simulated using a granular flow model, while wave propagation was modeled using the renormalisation group (RNG) turbulence model. These two models were coupled to analyze the genaration and evolution of the landslide-induced surge waves. The simulation results indicate that the peak sliding velocity of the landslide approached 20 m/s. As the landslide mass entered the Dadu River, a large landlside-dam formed, temporarily blocking the river and genrating intense surge waves. The peak water velocity increased to 30 m/s, and the maximum wave height reached 81.78 m, which is consistent with historical record-roughly 80 m. The surge waves propagated in a circular pattern toward the opposing riverbank. The findings provide insights for the risk assessment of landslide-induced surge waves.