Analysis of landslide-generated impulsive waves using a coupled DDA-SPH method

Large impulsive waves generated by slope failures and a subsequent landslide in a reservoir area may lead to serious damage to the dam, shoreline properties and lives. Therefore, analysis of landslide-generated impulsive waves is of significant importance for hazard prevention and reduction. There are three key points for analyzing this problem: (i) the landslide run-out, (ii) the free surface flow and (iii) the landslide-water interaction process. The Discontinuous Deformation Analysis (DDA) method was previously developed to investigate discontinuous block movements, while the Smoothed Particle Hydrodynamics (SPH) method was used mostly to model free surface flow. However, the solid-fluid interaction is seldom considered in the respective fields, which greatly restricts their applications. For this reason, the coupled DDA-SPH method was proposed in this study to solve the solid-fluid interaction problem. To validate this approach, this study considered a wedge sliding along an inclined plane and interacting with the water body. The corresponding Heinrich's experimental results were adopted to evaluate the accuracy of the coupled method in modeling the landslide movement and wave profile, proving that the landslide motion and wave profiles could be captured accurately by the coupled method. Finally, the effect of the governing parameters on the wave amplitude was discussed.