Analysis of Structural Characteristics of Underground Cavern Group by Simulating All Cavern Excavation

The traditional Three-dimensional (3D) model for stability analysis of a large underground cavern group only includes the main powerhouse, transformer chamber, tailrace surge tank, electrical wire hall, and part diversion tunnel tailwater tunnel. Other caverns excavation are not taken into consideration, which is inconsistent with actual project. In this study, 3D Finite Element Method (FEM) model, including all cavities, simplified containing cavities were established based on We study structural characteristics during via nonlinear FEM. At same time, three numerical calculation schemes designed comparison. results show that simulated distributions stress field, deformation plastic zone two models similar, but magnitudes FEM considers generally higher than model. difference between horizontal displacements powerhouse reaches 53.72%. Therefore, from perspective engineering safety construction, it advisable to adopt when conducting simulation group.