Optimum Design Of Excavated And Filled High Loess Slope In Yan'an Based On Reliability Theory

In recent years,with the further implementation of the strategy of west china extensive development and promoting of the engineering construction of "The Belt and Road",great progress has been made in the project construction of the hilly-gully loess region in Yan'an,accompanied a lot of digging and filling high slope which cause the stability evaluation of digging and filling loess high slope and ecological environmental problems can't be ignored.This paper was based on excavated and filled high loess slope in Yan'an,through field investigation,laboratory test and theory analysis,using reliability theory to optimize the design of excavated and filled high loess slope in Yan'an,the research results are as follows:(1)Monte-Carlo method is used to simulate the reliability index and failure probability of typical loess high slope in Yan'an.The reasonable sampling number of slope stability is calculated by Monte-Carlo method.(2)The soil parameters of excavated and filled loess slopes in Yan'an were analyzed statistically by a variety of methods.It was found that the coefficient of variation and the standard deviation by the random field model were the smallest,the linear correlation method was the next,and the point statistic method was the largest.Random field model considering the soil parameters in the autocorrelation law of spatial random distribution,thus the statistical result is more authentic;soil parameters' s distribution of the excavated and filled loess slopes conform to logarithmic normal distribution.(3)The relationship between the overall slope stability and the slope type is analyzed by the limit equilibrium method and the reliability analysis method.The comprehensive ecological protection technique which is suitable for the excavated and filled high loess slope in Yan'an is analyzed and summarized.(4)The slope construction cost as the objective function,the failure probability of slope as the constraint conditions,the optimization design model was established of the excavated and filled loess slope in Yan'an,and then the slope design programme of the excavated and filled loess slope in Yan'an was put forward.