| The Discrete Element Method (DEM) is verified to be suitable for the simulation of discontinuous media (e.g., jointed rock mass), and has been widely used in the modeling of slope stability, underground excavation and the dynamic behavior of rock mass. However, the DEM has not been so widely applied yet in China, due to lack of systematic investigation of the method.This thesis investigated the application of the DEM in the excavation of rock tunnels on the Jinping Auxiliary Tunnel which governs the final completion of the Jinping Hydropower Station Project. Based on the review of the existed geological exploration data and geological mapping at working faces, the rock deformation pattern due to tunnel excavation was successfully investigated by using the Universal Discrete Element Code (UDEC). The comparison with the field monitoring results showed that the DEM is excellent in jointed rock mass modeling; The Bassett Convergence Technology was used to monitor the deformation of tunnel intersection during the construction, the comparison with the monitoring data using conventional methods verified its feasibility and effectiveness; UDEC was also applied to analyze the mechanism of the straight-hole cut method, which proved the effectiveness of the staged cut method in rock mass with high tensile strength. By using the function of explicit finite difference in UDEC, the mechanisms of several often used rock burst prevention methods were investigated. The result provided a theoretical basis to the rock burst prevention design in Jinping Auxiliary Tunnel. Finally, the key technology in using UDEC was summarized, which would be very useful for the further application of UDEC in rock tunnel excavation.Based on the above study, the UDEC application technology in rock tunnel excavation was investigated, in order to provide a solid basis for the wide application of UDEC in China in the future. At the meanwhile, the achievements would greatly benefit the further study of the specific field.
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