Quality Evaluation and Numerical Simulation of the Rock Mass of the Assembling Chamber of Shenxigou Hydropower Station

Surrounding rock of the assembling chamber of Shenxigou Hydropower Station was classified with the “RMR” method. A finite difference model based on the latest Hoek-Brown criterion was used to analysis the stability of the assembling chamber and the calculation results were compared with the monitoring data. It was demonstrated that according to the RMR classify method there was surrounding rock of class IV and III in every section of the assembling chamber. Terrane Zbdn1belonged to surrounding rock of class IV which was of poor quality, and terrane Zbdn2, Zbdn3belonged to surrounding rock of class III which was of average quality. Based on the latest Hoek-Brown criterion, the parameters of rock mass were estimated, in which the influence of the structure of the rock mass, the strength of rock block, state of stress and other factors were taken into account. It was efficient, fast and economic. Excavation process of the assembling chamber was simulated using finite difference technique FLAC3D, whose calculation results showed to be compatible with the monitoring data.