Numerical modeling of landslide generated impulsive waves using coupled DDA-SPH method

摘要

Slope failures on the margins of dam reservoir can generated large impulsive waves.Impulsive waves with considerable wave amplitude is able to cause serious damage to the dam body,shoreline properties and lives.Thus,the study of the slope failures,impulsive wave generation and their consequences are of paramount importance for hazard prevention and reduction.Previous numerical studies had made great efforts focusing on the fluid phase,but lacking of the consideration of solid impact.However,as the nature of the two phase problem for landslide generated waves,consideration of fluid and solid interaction is of great significant.In this study,the coupled DDA(Discontinuous Deformation Analysis)-SPH(Smoothed Particle Hydrodynamics)method was used to take the solid fluid interaction into account.In specific,the SPH method was employed to represent the fluid motion by solving the full Navier-Stokes equations,and the landslide movement of a block system was reproduced by the DDA method.Additionally,the coupled scheme of the DDA and SPH method was highlighted to explain the implementation of solid and fluid interaction.As a test case,the study considered a wedge sliding along an inclined plane and interacting with the water matrix.The corresponding experimental results by Heinrich was adopted to evaluate the accuracy and performance of the coupled method in terms of the landslide movement,and wave profiles at typical instants.It is concluded that for the more common practical engineering cases of landslide generated waves,the coupled DDA-SPH method is adequate to describe the phenomena with promise accuracy due to the consideration of solid and fluid interaction.