Reliability And Sensitivity Analysis Of Slope Stability With Stochastic Response Surface Method

There are many uncertainties in the design,construction and control of slope engineering,such as environment and material parameters.In order to consider the influence of uncertain factors on slope stability,it is necessary to carry out the stability reliability and sensitivity analysis of slope,which provides theoretical basis and technical support for risk evaluation and control management of slope engineering.In view of the fact that the traditional evaluation method of single safety factor can not consider the influence of many uncertainties on the stability of slope,for the scientific and reasonable evaluation of slope stability,combined with the theory and method of slope numerical analysis and reliability analysis,the failure probability and reliability index are the safety evaluation indexes,from slope stability and In the aspects of deformation and system reliability,the reliability of slope stability is analyzed by multidimensional Analysis,and the relativity of mechanical parameters of slope materials and the influence of variability on slope reliability are discussed.The main research contents are as follows:(1)Combining Latin hypercube sampling(LHS)sampling and Nataf transformation,a stochastic response surface analysis model based on Polynomial chaotic expansion(PCE)for slope reliability is established,and the stability reliability of three-layer rock slope and rock slope with soft structure surface is analyzed.The stochastic response surface method based on PCE can make full use of the existing numerical analysis software,and can effectively improve the computational efficiency and meet the computational accuracy.The effect of the correlation of shear strength parameters on slope reliability is studied by using stochastic response surface method,and the sampling calculation effect of common sampling collocation method on slope random response surface is compared and analyzed.(2)On the basis of summing up the method of determining maximum allowable deformation of rock slope,using stochastic response surface method based on PCE to analyze the deformation reliability of rock slope with soft structure surface,The mathematical relationship between the slope deformation failure probability and maximum allowable deformation value and the influence of random input parameter variability on slope deformation reliability are studied.(3)Considering the relativity between multiple potential failure modes of slope,a reliability analysis model of slope system based on stochastic response surface method and conditional probability is established,and the stability and deformation reliability analysis of rock slope with soft structure surface is carried out.The results show that the proposed method can obtain more accurate calculation results of slope system reliability,and the failure probability of slope system is larger than that of single failure mode considering the conditional probability method with multiple failure modes.(4)A slope reliability sensitivity analysis method based on stochastic response surface method and JC method is proposed.On the basis of using the stochastic response surface method to obtain the approximate explicit expression of the slope function function,the reliability sensitivity analysis model of slope stability based on the First order reliability method(FORM)sensitivity factor is established with JC method.The accuracy of the proposed method is validated by the single factor sensitivity analysis method combined with two slope examples.