基于GIS 和极限平衡法的区域斜坡稳定性分析

Regional Slope Stability Analysis Based on GIS and Limit Equilibrium Method

区域斜坡稳定性分析是进行斜坡风险评价的重要前提。为了快速和准确地评价区域斜坡稳定性,开发了一种基于GIS和极限平衡法(LEM)的GIS-LEM工具箱。首先,基于所获取数据的分辨率和区域工程地质条件,将研究区离散成标准的斜坡单元体。其次,通过二维边坡模型确定斜坡潜在的滑动面,并利用多种极限平衡法计算区域稳定性系数。最后,基于GIS和Python开源语言,开发了GIS-LEM工具箱以实现极限平衡法在区域斜坡稳定性系数中的求解。将所开发的工具箱应用于汶川区域斜坡稳定性分析和风险评价中,并与无限斜坡模型的计算结果进行对比。结果表明约50%的同震滑坡分布在极高和高危险性区域,57%的非滑坡分布在低和极低危险性区;基于GIS-LEM工具箱所计算出的斜坡稳定性系数相对于无限斜坡模型平均预测准确率提高了16%。

Regional slope stability analysis is an important part for developing slope risk assessment.A GIS-LEM toolbox has been developed based on GIS and the limit equilibrium method to quickly and accurately calculate stability coefficients for regional slope stability.First,based on the resolution of the obtained data and the regional engineering geological conditions,the study area is discretized into numerous standard slope units.Secondly,the two-dimensional slope modelis used to determine the potential sliding surface of the slope,and the regional stability coefficients are also calculated by various limit equilibrium methods.Finally,based on GIS and Python open-source languages,the GIS-LEM toolbox was developed to solve the limit equilibrium method in regional slope stability coefficients.The developed toolbox was applied to examine the stability coefficients of slopes and risk assessment in the Wenchuan areas.Then,the prediction performance calculated by the toolbox was validated using post-earthquake landslide data and is compared to that of the infinite slope model.The results indicate that approximately 50%of the coseismic landslides are distributed in very high and high-risk regions,with 57%of non-landslide areas being distributed in low and very low-risk regions.Compared to the infinite slope model,the averaged prediction accuracy using the GISLEM toolbox increased by 16%.