Evaluation And Analysis On High Side Slope Stability Of Permanent Ship Brake In Three Gorges Project

Three Gorges Project is the largest hydroelectricity engineering in the world, and the high side slope of its permanent ship brakes is also rare. So studying stability and measures of reinforce of the slopes are mush necessary. The reason is that high side slopes of the permanent ship brakes has the stability of rock with brittle joints. After digging deeply at the ship brakes area , the high side slopes come to be the stress of the rock redistributed with the effect of ground stress field which is mainly composed of horizontal structure stress. In the area near the face of the slopes stress in the direction parallel the slopes is concentrated, but in the vertical direction the stress is unloaded. This form a large portion of the rock stress exceeding the ultimate strength and forms pull shear area, transpression plasticity area or yield area in which the former brittle joints extend, range into each other or new cracks occurred. The possible pattern of destruction is the rock in the plasticity area sliding along any possible plane that need checking when we analyze the stability of the side slopes.The geologic case in the side slopes area is the basis of analysis stability. In this article, First, the geologic cases in the area are described according to the reconnaissance record. Then, the major factors affecting the stability of the side slopes are discussed, such as Configuration, repelling pull area, height, angle, ground water, explosive effect, character of rock, case of support, ship brakes run singularity, and so on. At last, block theory and vector analysis are used for character analysis.Based on preparatory work of theory and geologic reconnaissance record that is analyzed and collated before or to find the blocks constructing the side slopes of the ship brakes. After execution, we can use the block theory count each block according its whole stability, and analyze its stability and get the preliminary ategory, then, find out key blocks affecting the conclusion. Finally, the further stability analysis of key blocks as well as the side slopes of the ship brakes according to the support design and come to step result are made out.