Mechanism and numerical simulation of reservoir slope deformation during impounding of high arch dams based on nonlinear FEM

The mechanism of reservoir slope deformation during impounding still lacks a convincing explanation. A generalized effective stress principle for rock masses is presented. A nonlinear iteration algorithm has been proposed and implemented in a 3D FEM program, TFINE. A case study of the Jinping-I high arch dam is then presented, and the calculated values of reservoir slope deformation agree well with the measured values. The results show that the change of the yield surface for the reservoir slope induced by adopting the effective stress principle results in plastic deformation, which is the main reason for slope deformation during impoundment.