Study On The Nonhomogeneous Of Soil Parameters And The Influence On Three-Dimensional Slope Stability

Due to historical differences in stress and sediment,soil parameters have strong spatial variability.The application of random field model to describe complex spatial variability of soil parameters has become one of the focuses in geotechnical engineering.In recent years,more and more scholars have realized that the spatial variability of soil parameters has significant non-homogeneous characteristics.However,the non-homogeneous random field model of soil parameters proposed by researchers at present is all evolved from the homogeneous random field model,which lacks verification of in-situ test data.In fact,soil parameters usually have stratification along depth,but this special spatial variation has been neglected in current studies.In a word,the non-homogeneity of spatial variation based on measured geotechnical parameters,especially the influence of stratification characteristics on spatial variability,needs to be further studied.Therefore,based on in-situ test data,the spatial variability and stratification characteristics of marine clay parameters in three Nordic countries are studied in this paper.Considering the coupling between soil parameters and the multi-parameter characteristics of geotechnical engineering,the similarities and differences of correlation between mean and standard deviation of soil parameters of marine clay in three different Nordic countries are compared and analyzed.The insufficiency of single site soil parameter is compensated by the same marine clay parameters in several regions.The data of multiple regions are analyzed as a whole and the spatial variability of mean and standard deviation of comprehensive samples of marine clay parameters is compared and analyzed.Based on the above analysis,a stratification non-homogeneous random field model of soil parameters is proposed.In geotechnical engineering,large linear three-dimensional(3d)slopes,such as embankments,dams and flood protection embankments,are usually simplified to twodimensional(2d)slopes to calculate,and the spatial variability along the length direction of the slope is therefore neglected.Existing long linear three-dimensional soil slope stability analysis method,considering the spatial variation of soil along the length direction and the influence of landslide soil end cross section,but this method can only get the critical sliding mass width,and the position of the critical sliding body can not be obtained.For most slopes,the variability of the slope profile shape along the slope length and soil parameters parameters is not negligible and can not be regarded as random variables,thus the assumption of long linear slope is not satisfied.Based on this,an improved reliability analysis method for 3d slope stability is put forward in this paper based on the above soil parameter stratification spatial variability.This method can obtain2 d and 3d safety factors,failure probability and reliability index of slope,width and position of critical sliding body of 3d slope,and calculate stability and reliability of nonhomogeneous 3d slope.Through a simple case,the reliability analysis method of long linear 3d slope stability is compared with the improved 3d slope stability reliability analysis method,which proves the accuracy and rationality of the improved 3d slope stability reliability analysis method proposed in this paper.Finally,the model built in this paper is used for stability reliability analysis of a real high fill slope project,and the practicability of the model and method established is verified.