Reliability analysis of rock slope based on uncertainty of joint geometric parameters

Based on the fact that the stability of rock slope is mainly controlled by joint,and the random distribution of joint makes slope has high degree of uncertainty,the reliability analysis approach of rock slope considering uncertainty in joint geometric parameters governing slope stability was provided. In order to bring the approach,a rock cutting slope project in Xiarong highway was considered. The probability distribution models of joint geometric parameters were studied by probability map method and the theory of mathematical statistics to determine statistical parameters and probability density functions for each joint geometric parameters. Since factor of safety gained by Sarma method fitted to wedge failure had implicit function,based on the response surface method,the approximate explicit expression of calculation stability coefficient was made; the analytical model of reliability for slope stability analysis based on random properties of joint geometric parameters was explored,and the limit state function needed by rock slope reliability analysis was established. Taking joint origination and joint spacing as random variables,reliability analysis of rock slope was investigated by applying random data which were derived form Monte Carlo Method in accordance with the distribution models. The results show that the brought method can reflect the reliability of rock slope controlled by discontinuities,and that it can provide some reasonable and reliable references for rock slope stability evaluation and supporting design.