Analysis of bank slope stability with local seepage variation in Three Gorges Reservoir

摘要

In order to analyze stability change of bank slope when rainfall and water level variation induce the local seepage variation, firstly, the Baitupo slope is selected as the typical slope at Badong new county in Three Gorgers reservoir. The seepage-zoning model of bank is built according to integrality of rock core and lithologic character. Then, water-soil characteristic curve was determined by empirical formula and cngineering analogy; based on the theory of unsaturated seepage, local seepage field of the bank slope was molded by using SEEPAV software. Finally, we analyze the change process of bank slope stability with local seepage variation. It is concluded that local is divided into two segments by F3 fault that has faint permeability, the front part groundwater change is more hysteretic than the back part when water level change. The local seepage variation have great influence to bank slope stability, the stability of bank slope is most poor when water level drop quickly. The shear strain increment zones of bank slope locates in the weakness zones, and, the potential sliding surface develops consequently to layers.