Analysis of abutment stability of concrete arch dam by three-dimensional nonlinear FEM

The stability of arch dam abutment is one of key factors for the dam safety.At present,the stability analysis of arch dam abutment mainly depends on rigid body limit equilibrium method that does not consider the elasto-plastic deformation of rockmass and can not simulate the complexity of the rockmass structure.As a result,application of the method cannot reflect the destructive mechanism of the dam abutment rockmass,as well as the integral effect between dam body and bedrock.We carry out an analysis on anti-slide stability of the dam body and abutment rockmass by three-dimensional nonlinear FEM based on the theory of elasticity and plasticity of materials.The anti-slide stability of arch dam abutment rockmass is evaluated in two ways of mutation load and material strength decreasing gradually respectively.The analysis results indicate that,nonlinear FEM method is an effective tool for analyzing the stability of arch dam abutment and its application can well reflect the interaction between arch dam and the bedrock.