Study On Landslide Surge And Its Impact Effect On Gravity Dam Based On SPH Method

In extreme case, especially in the narrow valley, reservoir slope is likely to be instability and resulting in a large number of stone body into the river bring about huge surge. The surge impacts channel and water retaining structure, it is a great threat to downstream residents’ personal and property securities. Nowadays, our country’s water conservancy project mainly concentrated in the southwest of the regional engineering geological conditions of high slope, soft soil, such as landslide surge problems stand out increasingly. So the study of landslide surge process, influencing factors and its impact effect on dam are particularly significant.We studied surge generation and propagation process, and discussed influences of particle space, initial falling velocity, water depth and slider width these four factors to surge in the numerical simulations, the surge process and impact pressure of right boundary were given. The impact to gravity dam under high and low water were also taken into account. This paper mainly does work as follows:(1) Firstly, we establish the model of rigid sliding into the water based on the SPH(Smooth Particle Hydrodynamics) method, the whole process of landslide surge was simulated, the slider displacement-time curve and swell during different time, slider and the fluctuation of fluid distribution were given. By comparing the amplitude and the free surface wave, we verify the feasibility of SPH method in simulating surge and the reliability of the model.(2) Taking variable control method, by setting different variable parameters, to analysis their influences of the particle space, initial falling speed, water depth and width of the slider these factors are considered in the slide surge numerical simulation.(3) Using Koyna gravity dam as the research object, the SPH and finite element coupling model is established, and through static comparison between ANSYS model and coupling model to validate its reliability. On this basis, we studied the effect of swell on dam crest displacement, pressure on dam upstream face and the dam stress under high and low water level. Numerical simulation results show that not only swell impact effects on the dam, the compression wave in the effect also cannot be ignored.