Research On The Stability Of The Taishan Underground Powerhouse Caverns

Pumped storage power station project construction in China is increasing, the security and stability of pumped storage power station underground cavern group problem is becoming more and more attention. In this paper,based on the engineering background of taishan pumped storage power station, using theoretical analysis, experiment research and numerical study of the means of combining safety for underground cavern group carried on the thorough research of the system, and the stability of the pumped storage power station underground powerhouse cavern group of significance of reference to the long-term stability of the research.The main research content of this article has the following several aspects:(1) Laboratory experiments and field studies. In this study, Taishan pumped storage power station and the right bank of the main cavern rock sampling, rock uniaxial creep tests carried out to obtain the rheological characteristics. Based on the test results and proposed appropriate expression of the region rheological properties of rock rheological model and model parameters. In this study, also carried out geological radar. Detection site for the water conveyance tunnel under the working group level segment 3#,4# and 3# fork tube manifold section.(2) The key block search and identify research. Statistical analysis of the geological characteristics of faults and joints, using a computer program were drawn powerhouse joint fissures, faults and dikes trend rose diagrams and stereographic pole diagrams, use probability theory to analyze the region joints and other production-like features. Were drawn critical areas densely jointed stereographic projection, the effects of different joints occurrence of faults, such as the security and stability of underground caverns. This paper estimates the probability of five different buckling instability mode, drawn mainly instability types.(3) Stability analysis of water diversion system uptime and vented. The establishment of a three-dimensional model of Taishan Pumped Storage Power diversion system. Were calculated and analyzed the normal operating conditions and maintenance conditions of the surrounding rock stress, displacement and plastic zone. Two conditions were analyzed shaft diversion, diversion tunnel, water fork tube and water adit stability.(4) Underground cavern group of long-term stability of the overall three-dimensional analysis. The establishment of a three-dimensional model of caverns, and the inversion of initial stress field. According to the results of numerical analysis, analysis of the stress distribution of three-dimensional underground cavern group, the displacement distribution and distribution of plastic zone, on this basis, the use of empirical formula method, standardized method and the method of loose plastic zones around the Taishan Power Plant rock stability analysis and evaluation.