Erlongan Slope Failure Analysis Based On Stochastic Finite Element Metnod And Local Random Field

Slope stability has always been an important problem in geotechnical engineering field. Because there are obvious spatial variabilities in geotechnical materials, even a single soil layer, the localized characteristic parameters between different points also exist certain differences, so that the calculation results based on the deterministic analysis of the slope stability is limited. Aiming at this problem, considering the spatial variation of parameters of soils in geotechnical engineering, we developed the stochastic finite element analysis program that based on the Monte Carlo method (Monte Carlo), the slope’s safety factor, failure probability and landslide causes that happens in Erlongan of Guzhang city of Hunan province and the slope stability law under the condition of spatial variation influence are depth analyzed, the specific research contents and results are as follows:(1) Investigate and survey the related research about the spatial variability, stochastic finite element analysis and slope reliability analysis in geotechnical engineering at home and abroad, and these research has been classified.(2) Based on limit equilibrium method and Monte Carlo (Monte Carlo) method the transformation parameters of soil level and distribution types of the influence of the landslide are studied in slope reliability analysis. The reliability analysis results show that the large with the slope failure probability Pf=50% the threshold value, when Pf> 50% above the threshold value with the variation coefficient increased failure probability decreases continuously, when Pf<50% is below the threshold value with the increase of variation coefficient failure probability is increasing; At the same time, attention should be paid to the negative appeared normal distribution resulting from too much variance when the random number producing process and the overall situation of lower value resulting from lognormal distribution of probability density function image shift.(3) There are obvious spatial variabilities, in geotechnical mediums under natural conditions, based on the relevant indicators of spatial variability (variance, reduction function of variance, correlation function, range, etc.) of homogeneous slope on the stochastic finite element analysis. The results show that:for different relative distance and variance, the spatial distribution of the localized parameters has a great diversity than slope slip crack face, which show the importance of considering the spatial variability analysis of the stability of slope.(4) Based on Monte Carlo (Monte Carlo) stochastic finite element method and finite element strength reduction technology, random field expansion and reliability analysis are used for analysis the slope that happens in Erlongwan of Guzhang city of Hunan province. Results show that compared with cohesive force, the internal friction angle in the soil of slip surface has a more significant influence on landslide,especially the second layer, and the numerical simulations of slip band has good relativity with the results of actual survey of slip band. Show that based on the random field of finite element analysis and the finite element strength reduction technique in slope stability analysis is of important application value.