Effect of groundwater on stability of slopes at reservoir bank

In allusion to the characteristic of easily losing stability for reservoir slopes when water level descending rapidly, the mechanism of losing stability resulting from ground water for reservoir slopes is analyzed. The important factors influencing the stability of reservoir slopes, such as decrease of physico-mechanical parameters, buoyancy and seepage force, are pointed out. The formulas for calculating the stability of reservoir slopes considering groundwater are given. A slope project in the Three Gorges is illustrated. The results show that the resisting force of potential sliding face decreases due to softening, that the buoyancy at a certain extent helps to enhance the stability of slopes, and that the seepage force in slope body is a key factor resulting in a slope losing its stability. In addition, for designing a slope project, it is necessary to adopt some reasonable measures effectively decreasing the disadvantageous influence of groundwater on the stability of slope, such as setting protecting, inversely filtrating and draining systems.