Impounding influence of slope and foundation deformation on high arch dam

Impounding deformation of slope and foundation is a noteworthy problem during construction and operation periods of high arch dams. Reservoir impoundment is accompanied with various impacts, including material degradation, effective stress decreasing and buoyancy in rock masses. These phenomena are related with some engineering concerns like landslide, dam stability and reservoir-induced earthquake. However, research on mechanism of impounding effects is still limited. By extending the strength reduction method (SRM) in slope limit analysis, a modified method named stiffness and strength reduction method (SSRM) is proposed and implemented in FEM codes to simulate material degradation. Moreover, the expression of effective stress for fractured rock mass with fluid is incorporated into the Drucker-Prager criterion. Based on monitoring data of left bank slope deformation and valley width reduction of Jinping I arch dam, the above two methods are applied in the analysis of impounding influence of slope and foundation. Results show that the dam has good capability against slope deformation, with displacement and stress fields locally changed. ©, 2015, Academia Sinica. All right reserved.