Reliability Analysis Of Slope And Random Response Of Anti-sliding Pile Considering Spatial Variability

In the analysis of slope stability,the spatial variability of rock and soil mass,as one of the sources of uncertainty in engineering,has a significant impact on slope reliability.However,traditional deterministic analysis methods cannot fully consider and describe the uncertainty in engineering,which leads to the inaccurate evaluation of slope stability.Secondly,anti-sliding piles,as a commonly used measure in landslide prevention,can effectively prevent the occurrence of landslides.However,there are relatively few studies combining the spatial variability of rock and soil mass with anti-sliding piles,and the influence of spatial variability on anti-sliding pile is still unclear.In view of above problems,this paper carries out reliability analysis of slope and random response of anti-sliding pile considering the spatial variability of rock mass and interlayer,and explores the influence of description parameters on slope reliability and random response of anti-sliding pile.Based on this,the main research contents and achievements of this paper are as follows:(1)Based on Hoek-Brown criterion and random finite difference method(RFDM),the influence of the spatial variability of rock mass and interlayer on failure probability is studied.Finite difference method is applied to verify the model considering spatial variability in literature.When considering the spatial variability of rock mass,the difference of failure probability between the values calculated by Monte Carlo simulation and response surface method is compared.The results show that the coefficient of variation,correlation coefficient and scale of fluctuation of parameters have obvious influence on slope reliability,and the influence of the spatial variability of interlayer on failure probability is greater than that of rock mass.After using FLAC to verify the slope model considering spatial variability in literature,it can be seen that response surface method can also be used for reliability analysis of slope in FLAC.After using response surface method for reliability calculation,the obtained failure probability is similar to that obtained by Monte Carlo simulation,which illustrates the feasibility of this method.(2)After the deterministic analysis of slope under the conditions of different anti-sliding pile positions and pile lengths,the slope reliability under the conditions of different anti-sliding pile lengths in the middle of slope is calculated based on SLIDE2.The random response law of anti-sliding pile considering spatial variability is explored,and the results are compared with deterministic analysis results.The failure probability of slope reinforced with anti-sliding piles is estimated.The results show that when anti-sliding pile is located in the middle of slope and the spatial variability of interlayer is considered,the reliability index does not always increase with the increase of pile length.At the same time,lower slip surfaces appear.When considering the spatial variability of rock mass and interlayer,the random response laws of anti-sliding pile are different.When considering the spatial variability of rock mass,the mean value of pile top displacement is larger than the value calculated by deterministic analysis,while the mean value of the maximum bending moment is smaller than the value obtained by deterministic analysis.Because spatial variability has a negative impact on the bearing capacity of pile.When considering the spatial variability of interlayer,the mean values of the pile top displacement and the maximum bending moment are both smaller than the values obtained by deterministic analysis,indicating that the spatial variability of interlayer is beneficial to the stability of pile.(3)Taking the landslide in Chongqing as an example,after deterministic analysis,the influence of different layers on slope reliability is studied.Slope reliability and the random response of anti-sliding pile considering the spatial variability and rotational anisotropy of sliding mass are studied.The safety factor obtained from Monte Carlo simulation is fitted to estimate the failure probability of slope supported by anti-sliding pile.The results show that the spatial variability of sliding mass has a great influence on the slope reliability.Compared with random field variables,treating strength parameters as random variables will overestimate the failure probability of slope,which will result in waste of supporting materials.When the spatial variability of sliding mass is considered,the coefficient of variation has the greatest influence on failure probability.When the rotational anisotropy of sliding mass is considered,the failure probability varies with the rotation angle.The spatial variability of sliding mass makes the mean value of the top displacement and the maximum bending moment of anti-sliding pile greater than the values calculated by deterministic analysis.It is speculated that ignoring the spatial variability of sliding mass will not be conducive to ensuring the supporting effect of the anti-sliding pile.