SPH-DEM coupling method based on GPU and its application to the landslide tsunami. Part II: reproduction of the Vajont landslide tsunami

Landslide tsunamis are complex fluid-solid coupling processes that often cause enormous catastrophes. In this study, the smooth particle hydrodynamics (SPH) and discrete element method (DEM) coupling algorithms are used to simulate the tsunami which was induced by the 1963 Vajont landslide, Italy. In order to simulate the failure process of the landslide, a DEM numerical model is constructed based on the geological structure of the landslide, and contact parameters for the DEM particles are inverted according to the laboratory tests. Based on the numerical results, the whole process of the tsunami by the Vajont landslide is reproduced in detail. Comparisons show that the simulated motion and accumulating characteristics of the landslide, the climb-up and peak overtopping flow of the tsunamis, and the load on the dam by the tsunamis agree well with the published results. The simulation also indicates that the right bank slope of Vajont Dam is the major spillway of the flood, thereby significantly reducing the flow directly over the dam, which is helpful to stabilize the dam; and the concrete of the left abutment is damaged by the mixture flow of water and geomaterials with a higher velocity (approx. 35 m/s at the max.). The overtopping depth decreases from the north bank to the south bank. The maximum depth on the right abutment and the left abutment is approximately 80 and 65 m, respectively, lower than the reported estimation of similar to 150 m. This study shows that the coupled SPH-DEM method and the developed code-CoSim-work well for the analysis and research on landslide tsunami.