NUMERICAL LONG-TERM STABILITY OF DAM ABUTMENT RESISTANCE BODY FOR A HYDROPOWER STATION IN SOUTHWEST CHINA

Long-term stability of dam abutment resistance body is very important for a hydropower station.The abutment resistance body stability of complex rock mass dam under the action of water thrust is particularly important.There are widely altered rocks in the dam abutment of a hydropower station in Southwest China.On the basis of altered rock rheological property and its viscous-elastic-plastic constitutive model,the stress and deformation fields characteristics in the resistance body slope have been simulated with 3D numerical method during the reservoir operation period.The study results show that te third stress field is formed after 6months of water storage.The dam abutment resistance body is in the most dangerous situation.Local destruction between altered rock and fault may appear.According to the simulated deformation value and plastic zones after 5 years of water storage,the abutment resistance body of the whole dam is in a long-term stable state.