Analysis Of Surrounding Rock Stability Of JinPing Underground Hydropower Station

Since reformation and opening, the National Economy of our country is developing rapidly. Our country and Party try best to develop base establishments such as energy resource and traffic, and the outlook of utilizing underground space is very promising.Many large scale hydropower stations of our country are built in gorges among high mountains and some of them adopt the type of underground powerhouse. The caverns of the underground powerhouse are crossing and the sidewalls of the main caverns are high and the spans of the main caverns are wide. The stability of surrounding rock is very important both in the course of excavation and in the period of running. The underground project includes some characters as follows: the mechanical property and geological structure of the surrounding rock is complicated and the crustal stress field, underground water and the course of excavating is uncertain, etc. Up to now, there hasn't been common method and criterion of the stability of the surrounding rock.Jinping hydropower station is located in Liangshan country, Sichuan province, and has 3600MW power capacity. The project is built for electricity generation. According to the condition of the Jinping project, the stability of the underground powerhouse's surrounding rock is studied and evaluated by using nonlinear finite element method (FEM) and attending to the change of displacement, stress and failure area. The achieved main conclusions are as follows:(1) The crustal stress field is a high one which formed with gravity stress and tectonic stress, and the tectonic stress is dominating. The orientation of the tectonic stress is cross river and upright.(2) In the whole, the surrounding rock of the underground powerhouse is stable with...