Based On The Uncertainty Of The Geometric Parameters Of The Joints, Slope Stability And Reliability Studies

The stability of rock slope is mainly controlled by joint. It is the random distribution of joint that results in slope stability system having a high degree of uncertainty. So study on the effect of joint parameters on the stability of slope is significant. Reliability analysis has been used as an effective tool to evaluate uncertainty so prevalent in variables. In order to bring reliability analysis approach of rock slope considering uncertainty in joint geometric parameters governing slope stability, the low grade metamorphic rock slope project is considered. Then the probability distribution models of joint geometric parameters were studied by probability map method; and the interaction between slope face and structural plane was analyzed to determine the pattern of slope failure by stereographic projection, respectively. In addition, according to Monte Carlo simulation method, the analytical model of reliability for slope stability analysis which based on random properties of joint geometric parameters was established. The main results can be summarized as followed:(1) The detailed joint survey and the geology sketch of superficial were made. Meanwhile advantage occurrence of joint was determined by using stereographic projection method. Statistical parameters and probability density functions for each joint geometric parameter were studied by probability map method and the theory of mathematical statistics. At last, the probability distribution models of joint geometric parameters were determined.(2) The stereographic projection method was used to determine the relationship between slope face and structural plane and stability analysis of rock mass. Then, the pattern of slope failure was discriminated and the volume of landslide was predicted. (3) According to quality evaluation system GSMR, mechanical parameters of rock mass and its distribution regularities were determined. By the effect analysis on mechanics parameters of jointed rock mass which caused by joint geometric parameters, based on the least square method, the mathematics model between joint geometric parameters and mechanics parameters of jointed rock mass was established.(4) Taking the joint geometric parameters for random variables, the limit state functional function needed by rock slope reliability analysis was developed. Reliability analysis of rock slope was investigated by applying random data which derived form Monte Carlo Method. By combining with deterministic analysis method, the comprehensive evaluation of slope stability for each joint surface combination was presented. The results showed that the rock slope was instability.