基于GRASS GIS与TIN滑动面的边坡三维极限平衡方法研究  

Three-dimensional limit equilibrium method based on GRASS GIS and TIN sliding surface

作　　者：刘振平[1] 杨波 刘建[1] 贺怀建[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]湖北省交通投资集团有限公司襄随高速公路建设指挥部,湖北襄阳441000

出　　处：《岩土力学》2017年第1期221-228,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金青年基金项目(No.51204158;No.51209198);国家重点研发计划项目资助(2016YFC0401802)~~

摘　　要：基于开源地理信息系统(GRASS GIS),建立三维极限平衡Hovland模型,研究了边坡稳定性计算方法。采用空间平面投影方法对椭球滑动面中各组成单元面积计算方法进行改进,提高了计算效率。考虑边坡主滑方向与各单元倾向之间的关系,给出了能反映正负变化的滑动面各单元安全系数表达式。通过引入约束Delaunay三角形剖分方法与网格优化算法来生成滑面不规则三角形格网(简称TIN)模型,弥补了Grid模型在滑动面边界准确表达方面的不足。相比Grid模型,在相同网格分辨率条件下,TIN滑动面获得的边坡整体安全系数更加接近正确解,能够有效提升计算精度。通过考题与工程实例,对所提方法与程序模块的正确性进行了验证。结果表明,通过分析滑动面上各单元的安全系数,可以进一步划分不稳定区域与阻滑区,能够为滑坡治理措施的制定提供重要参考。The method to calculate the safety factor of slopes was implemented into a three-dimensional （3D） limit equilibrium model in the open source geographical information system （GIS） GRASS GIS. The Hovland method was exploited to evaluate the slope stability of specified or randomly selected ellipsoidal slip surfaces. The spatial plane projection theory was applied to calculate cell areas of the sliding surface, which increased the computational efficiency. By considering the relationship between the main slope sliding direction and the inclinations of cells, the expression of safety factor was proposed for cells in the sliding surface, which was used to distinguish between positive values and negative ones. Furthermore, the sliding surface was expressed by a triangulated irregular network （TIN） model which was obtained by utilizing constrained Delaunay triangulation method and mesh optimization algorithm. Thus, the shortcoming of the Grid model for accurately representing the sliding border was substantially improved. The safety factor calculated by the TIN sliding surface was closer to the exact solution than the Grid model at the same resolution condition, which demonstrated that the computational precision was obviously enhanced. Finally, the proposed method was verified by the modules programmed in Python language, which was further applied to some typical case studies. It was shown that the safety factor of cells lower than 1.0 represented the unstable region and that greater than 1.0 indicated the resistance slide area in the slip surface. The results can provide an essential basis for the development of landslide treatment measures.

关 键 词：开源GIS 边坡稳定性 三维极限平衡方法 TIN滑动面 安全系数 

分 类 号：TU433[建筑科学—岩土工程]