Stability Analysis Of Jointed Rock Mass In The Plant Area Of Taishan Pumped Storage Power Station

Jointed rock mass is one of the most common types in the excavation process of underground caverns, its stability determines the overall stability of the underground cavern group, and also plays an important role in the long-term safe operation of the tunnel. In the paper, the engineering background is Taishan pumped storage power station, the stability of jointed rock mass is studied. Based on the reliability theory and the key block method, the failure mechanism of jointed rock mass is analyzed. Using probability statistical analysis method, the occurrence characteristics of the structural planes in the engineering area are obtained and the failure probability of various failure modes are predicted. Theoretical analysis and numerical simulation on the stability of random block and slope are carried out, and the main research contents and results are as follows:Research on statistics and failure probability of plant structure. There exist a large number of discontinuities in the plant area of Taishan pumped storage power station, Including joints, faults and rock veins, due to the geometric and mechanical characteristics of the structural plane has random characteristics, so analysis of its statistical characteristics as the basis for the following analysis. Based on the statistical summary of the joint fracture occurrence in the study area, the graph of the rose and the pole of the structural plane are classified by computer program, And the stability analysis of the stereographic projection method is carried out. In accordance with the characteristics of the structural surface of the region, the failure probabilities of different failure modes are calculated, the statistical characteristics and the most dangerous failure types and failure probability of the structure of the plant are obtained.Research on random block stability of underground powerhouse. On the basis of statistical analysis of joints and fissures, using UNWEDGE calculation tool to search the underground powerhouse random block, simulation and calculation the safety factor of random block. The block volume, weight and safety factor are obtained, analysis and evaluation the stability of surrounding rock of main powerhouse, and the long term stability of the surrounding rock is predicted. The supporting scheme is proposed and the supporting effect is checked. The top arch and side wall concentrated joint band was carried out using Rockfall software to simulation of rockfall trajectory. Finally, the influence of different excavation direction, different section form and rock mass alteration on the stability of the key block is studied.Stability analysis of underground cavern fork wedge. Numerical model for multiple fork is built of underground cavern, searched the key blocks of tunnel intersection respectively, statistical analysis of the safety factor of each block, considering the randomness of geometrical and mechanical characteristics of structural plane, and the difference of structure, analysis and evaluation of the stability of cross wedge in tunnel by means of the method of probability and statistics.Study on the stability of the slope and the rock wall crane beam. Generalized upper base slope model, based on limit equilibrium method, calculation software of rock and soil slope, calculate the stability of the slope of the upper base camp under 3 different conditions. And used the finite element strength reduction method to check the stability of the slope, the stability of the slope is obtained. At the same time, we also calculate and analysis the rock wall crane beam in different conditions, and the corresponding stability assessment results is obtained.