Study on bank stability and safety protection under conditions of rapid drawdown of the Three Gorges reservoir

The geological and hydrological conditions of the Three Gorges reservoir region are analyzed. The safety protection scheme with the vegetation, the geosynthetic material and its superiority for the bank in the region are put forward. A finite element model is established based on the test project. The non-linear analysis is carried out to simulate the unsteady seepage in rapid drawdown of the Three Gorges dam. On this foundation, by analyzing the variation of the displacement, stress, plastic failure fields, safety factor and geogrid-soil interaction under influence of unsteady seepage pressure, the failure mechanism of the reinforced slope are studied. The research results indicate that the vegetation geogrid reinforced slope has more emergency capacity owning to the adjustment of geogrid-soil interaction in the process of rapid drawdown. It is an effective protection scheme to ensure the integral stability of the bank in the Three Gorges reservoir region.