针对目前三维极限平衡方法研究与应用存在的不足,在Hovland三维模型基础上通过调整Hovland模型与修正Hovland模型中单元滑动面上垂直压力的表达形式,提出Hovland改进模型与修正Hovland改进模型,并借助GRASS GIS软件对某一经典三维边坡稳定性分析算题进行验算,结果表明:在同一栅格模型与相同分辨率条件下,改进后的计算模型获得的安全系数精度更高;通过Delaunay网格剖分算法生成满足点、线及三角形面积等约束条件的TIN,结合Hovland改进模型,提出基于约束Delaunay TIN三棱柱单元的边坡地质模型构建与稳定性分析方法,获得了比三维栅格模型高的计算精度,尤其在采用改进后的Hovland模型计算时,精度提升更加明显;考虑到分析方法在实际工程中的推广应用,围绕三棱柱边坡地质模型经济性与计算结果准确性两个影响计算效率的主要因素,研究了三角形个数、稳定性系数随最小三角形约束面积的变化规律,提出Delaunay TIN最优网格剖分面积评判指标,并给出了1/412~1/206的建议值。黑山露天煤矿工程实例表明,潜在滑坡体中部与后缘产生的阻滑作用,是采掘场南帮边坡稳定性系数较高的主要原因。
For the deficiency of research and application of the three-dimensional limit equilibrium method, the Hovland improved model and revised Hovland improved model were put forward after modifying the calculating method of vertical force on the element sliding surface in Hovland model and revised Hovland model, whose force analysis is relatively reasonable. Using the GRASS GIS software for the verification of one three-dimensional slope stability analysis, the results shows that when the resolution of grid model is the same the precision of stability factor calculated by improved Hovland models is higher. The slope geologic model construction and stability analysis method based on constraint Delatmay TIN tri-prism elements were presented by introducing Delaunay mesh generation algorithm which can take points, lines, triangle area constraints into consideration. By adopting the tri-prism slope geologic model, the precision of various calculation models was improved effectively, especially in the case of using Hovland improved calculation models brought up in this paper. Considering the computational efficiency and the balance between calculation accuracy and economy of tri-prism slope geologic model, the research of analyzing the variation of the number of triangles and the stability factor with the minimum triangle area was carried out and the optimal area evaluation index proposed is 1/412 - 1/206 in Delaunay TIN subdivision. The engineering case study of Heishan open-pit coal mine indicated that the effects of sliding resistance formed in the middle and front of landslide are the main cause leading to high slope safety coefficient in the southern stope.