Study On The Stability Of Surrounding Rock Stability For Underground Powerhouse Of A Large Hydropower Station In Yunnan

Underground cavern group of Hydropower station are buried deep in the rock mass.Due to the complicated geological conditions, criss-crossed with cavern, and thecomplex layout, it has very important significance for the stability research ofsurrounding rock of underground cavern group. On the base of the analysis ofengineering geological conditions of surrounding rock of underground caverns, use themethod a three-dimensional finite element modal, combined with the construction ofunderground caverns excavation and supporting method, this article inversion of initialstress field of surrounding rock about the underground caverns, analyzes the cause andthe distribution law of in-situ stress field analysis, and the deformation of surroundingrock, stress characteristics, yield zone and the stability of surrounding rock conditionsabout the whole process which from excavation to support, evaluation of thesurrounding rock’s stability of the main cavern, such as the underground powerhouse,main transformer chamber, tail water surge chamber, proves the feasibility of theoptimized excavation scheme, optimization and recommend the reasonable supportingparameters, supporting time, the excavation procedure. The results provide a scientificbasis for the implementation of the project.