Slope Stability Analysis Based On GIS And Limit Equilibrium Theory

The most obvious difference between stability analysis of single landslide and regional landslide is that, the former analysis is generally able to determine the scope of landslide, and based on which it is possible to collect the related geological and mechanical data to take the effective analysis with the application of limit equilibrium or digital simulation method; while as for the latter analysis, the traditional digital simulation method will not work effectively because the potential landslide scope could not yet been determined. Besides, due to the multiple influence factors which have complex relationship and impact, part of them are hard to be quantified, which adds more extra difficulty to the evaluation process.Base on the systemically introduction about the factor filtration and quantification of the regional landslide stability evaluation, this paper realizes the digitization, quantification and rasterisation of the evaluation by GIS. And with the application of GIS, the membership degree expression of evaluation factors could be realized, optimizing the traditional "either/or" expression. After the pre-treatment of the evaluation process, this paper uses the function of spatial analysis of GIS, establishes the fuzzy synthetic evaluation model in it, realizing the evaluation of regional landslide stability and the visual display of the evaluation results. The result indicates that in the study region, the approximately proportion of stable, fairly stable, less stable and unstable area is 10:4:5:7, which is roughly consistent with the result calculated by traditional superposition method.On the foundation of the regional landslide stability analysis, this paper chooses the region where exists potential risk of landslip as the key point to make stability analysis of single landslide. The calculation resulted from the limit equilibrium method and the application of C++ program to realize the Swedish circular point calculation, is consistent to the stability analysis of regional landslide, further verifying the validity of the stability analysis model of regional landslide based on GIS. This paper realizes the regional landslide analysis on the basic of single landslide analysis, making the organic combination of the semi-quantitative analysis and quantitative analysis.