The Analysis On Submarine Landslide Based On A SPH Depth-integrated Model

Submarine landslides can cause serious damage to the structures of ocean engineering. Submarine landslides generally characterized by high velocity, long sliding distance, even the slope is smooth, submarine landslides may occur, sliding mass has a strong impact on submarine pipelines, sliding mass will directly endanger the safety of ocean engineering facilities and cause huge economic losses.In this paper, the flow process of the submarine landslide is studied, the submarine landslides under the different conditions of water depth, slope angle, contact frictional coefficient and erosion rate are simulated, Comparing the time history curve of velocity, height, length of sliding body under the different conditions, the maximum sliding distance and velocity are summarized and the underlying influence of related physical parameters are discussed. Research results are helpful for providing technical reference for disaster warning of submarine landslide and site selection of the submarine pipelines route.Firstly, this paper systematically summarizes the type of submarine landslide, trigger mechanism, the characteristics of the submarine landslides, general research situation of submarine landslides and SPH depth integration method.Secondly, the basic theory of the SPH Depth-integrated method and the friction rheological model and erosion model were introduced in detail. The interaction between the sliding mass with water body should be considered during the process of submarine landslides, the free surface of sliding mass is affected by hydrostatic pressure before landslide and by the dynamic water pressure after landslide. The contact friction coefficient effect changes with the consolidation of sliding mass and the change of dynamic pressure. The inertia of erosion soil will increase the shear resistance at the bottom of the sliding mass.Thirdly, the SPH Depth-integrated method and Bing program are used to simulate the submarine landslide, the calculation results are analyzed. SPH Depth-integrated method simulate the three-dimensional submarine landslides, and compared the three-dimensional offshore landslides, the slip process of sediment is intuitively showed.Finally, the results of numerical simulation are summarized and the pattern is discussed: the influence of water depth is not obvious on the maximum sliding distance and velocity of submarine landslide, but the change of the slope and contact friction coefficient effect is obvious, When the erosion reaches 10-4m-1, the erosion effect is obvious. The SPH Depth-integrated model can consider the influence of water environment, also can consider the effect of the consolidation and erosion. The calculation is simple, SPH Depth-integrated method is suitable for simulation of underwater landslides.