Study On Slope Stability In The Change Of Reservoir Water Level

The Three Gorges reservoir is a region with many slopes. The stability of a slope is decided by the internal and external factors. The internal factors are intrinsic, and the external ones include earthquake, water (reservoir water and rain), carve, etc. After the sluice of the Three Gorges reservoir, the water level will often change between 175m and 145m every year, which causes some slopes partly or completely submerged. It is an important problem that the seepage caused by the reservoir water level decrease infects the Three Gorges reservoir running. The seepage and stability evaluation of a slope is not only a complicated theoretical task but also a significant engineering application problem. Nowadays, most seepage models on the underground seepage only involve the saturated region. On the unsaturated region, the true parameters are displaced through discounting the saturated parameters. It does not match with the fact, and has different with the fact.To analyze the slope unsaturated seepage field change and its affection to the slope stability when the reservoir water level fall, at first, the underground seepage theory and differential equation is deduced. Then some models about the soil and water special curve are introduced, at the same time, a new method is put forward. On the base of software ANSYS and APDL, a two dimension section unsaturated seepage program is edited. At last, the zhaoshuling slope on Badong County, the Three Gorges region, is taken an example; it is studied with the seepage theory. The water head and water table on zhaoshuling slope are simulated on the conditions of the Changjiang River water level fall from 175m to 145m at different speeds, and then the slope stabilities at different time are analyzed. The result is also discussed. The main content includes:1. The characteristic of the unsaturated soil is expatiated, such as matrix suction, soil-water characteristic curve and penetrate specialty, and especially the suction in the unsaturated soil is discussed deeply. Then a multinomial restrict optimize model is brought forward after some models on soil-water characteristic curve are analyzed simply.2. The soil-water potential theory and the generalized Darcy's law of the unsaturated soil are analyzed. The saturated and unsaturated basic differential equation is deduced in term of law of conservation of mass, and then it is dispersed by finite element method (FEM). At last, the two-dimension saturated and unsaturated slope seepage program about the reservoir water level depression is edited with the APDL language of ANSYS.3. The zhaoshuling slope on Badong on the Three Gorges reservoir is given as an example, which is simulated with the seepage program in condition of the Three Gorges reservoir water level depression by some speed. In fact, the zhaoshuling slope' seepage processes are analyzed on...