3D DAMAGE RHEOLOGY ANALYSIS OF DEFORMATION AND FRACTURE OF SURROUNDING ROCKS IN JINPING I HYDROPOWER STATION UNDERGROUND POWERHOUSE

Jinping I hydropower station is located in a high initial stress area,the surrounding rock is the marble and in this area behaves in obvious plasticity.After excavation,the deformation and cracking phenomena in the surrounding rock and support structures are obvious.In view of these features,a coupled damage rheology 3D model and analysis method and prediction method for incremental deformation due to crack opening are adopted for caverns stability analysis.And the computation displacement is compared with the field monitoring data.It is shown that the two results are in good agreement with each other.Furthermore,the long-term displacements of surrounding rocks are predicted and analyzed.