基于MeshPy的3DGIS与三维有限元数值计算无缝耦合方法

3DGIS与有限元数值计算耦合方法及其系统开发，是目前GIS与岩土工程交叉学科的重要研究内容。通过对MeshPy、GRASS GIS、vtkPython以及Scipy等多个开源库的探索与编程实践，以Python为“黏合剂”，构建了GIS与三维有限元数值计算无缝耦合的平台框架。在满足几何形状、Delaunay特性、角度、面积以及体积等约束条件下，通过MeshPy包含的Triangle与TetGen库获得能用于有限元数值计算的三角形与四面体网格，并阐述了限定Delaunay三角化（CDT）节点插入算法与四面体网格质量控制方法。以排土场为例，针对CDT网格建立的地表模型，结合vtkPython封装的模块与算法，提出了根据节点分布位置综合采用线性与三角形重心坐标的插值方法，有效消除了其他插值手段导致的部分地表高程畸变的现象。借助Scipy提供的矩阵运算模块，开发了邓肯-张E-? 模型，给出了采用中点增量法进行非线性求解的算法，并通过对室内大型三轴剪切试验的数值模拟验证了程序的正确性。最后，对准东露天煤矿北部排土场堆排过程开展三维有限元数值计算，结合GRASS GIS对排弃物料高度与厚度空间分布规律的分析结果，对排土场边坡位移变化规律进行初步研究，结果表明，排土场垂直位移与排弃料高度及厚度相关，而最大水平位移则出现在各台阶坡体边缘位置，与实际情况一致。

Seamless coupling method of 3DGIS combined with 3DFEM simulation based on MeshPy

Coupling and systematic development methods of three dimensional geographic information system (3DGIS) and finite element method (FEM) have recently become the research hotspot in interdiscipline of geotechnical engineering and GIS. By explorating and programming of open source libraries such as MeshPy, GRASS GIS, vtkPython and Scipy, and using Python as "glue", the platform framework of seamless coupling between GIS and 3D FEM was eventually built. Under the constraint condition of geometry, Delaunay properties, angle, area and volume, MeshPy's Triangle and TetGen library were used to generate the triangle and tetrahedron grids for finite element numerical calculation and the insert algorithm of constrained Delaunay triangulation (CDT) and the grid quality control method were expounded. Combining with related module and algorithm provided by vtkPython, the surface model of a coal mine dump was established and a new interpolation method considering both lineament and triangle barycenter coordinate was put forward, which can effectively eliminate the elevation distortions in certain areas. The program including Duncan-Chang E-μ model and nonlinear solution algorithm based on mid-point incremental method was developed and was verified by the numerical simulation of indoor large-scale triaxial shear test. Finally, taking Zhundong coal mine as an example, the 3D finite element numerical calculation about the heaping process of the northern dump was carried out. Combined with the spatial distribution of material height and thickness in GRASS GIS, a preliminary research on the displacement variation of dump slope was accomplished. It is shown that the vertical displacement is mainly controlled by material height and thickness. The maximum horizontal displacement mainly appears in slope edges of each step, which is consistent with the actual situation.