基于裂隙连通路径和数值模拟的岩体渗透性评价

发布时间：2018-06-25 19:26

本文选题：裂隙岩体 + 离散裂隙网络模型　；参考：《南京理工大学》2015年硕士论文

【摘要】：裂隙岩体内部因包含了众多不连续的结构面而形成一个离散裂隙网络。这些岩体中的裂隙构成了携带有放射性核素流体的潜在流通路径。岩体中流体流动的分析在岩土工程和水文工程中都非常重要,由于岩体中裂隙空间分布的复杂性,目前岩体渗透性的分析多是基于蒙特卡罗方法所生成的离散裂隙网络模型。本文通过对高放废料处置库预选场址甘肃北山的实地勘察测量,获得场区大量的裂隙信息,分别对实测的二维裂隙网络模型进行了渗透性分析和对基于蒙特卡罗方法生成的三维裂隙网络模型进行了渗流路径搜索和渗透特性分析。借助近景摄影测量的方法,获得露头面上裂隙端点的三维坐标,并将其转化为露头面上的局部二维坐标,通过离散元方法建立该区域的二维离散裂隙网络模型,选择三个区域分别进行渗透性分析,获得三个区域的拟合渗透椭圆,并得到其在该露头面内的渗透张量和渗透主值及方向。根据大范围内各分块的体密度和其他裂隙信息通过蒙特卡罗方法建立3D模型,得到与实际裂隙分布情况较为符合的三维离散裂隙网络模型。基于VS2010平台,运用DFS算法得到整体研究区域三个主要方向的较短渗流路径,同时运用图论中Dijkstra算法得到三个主要方向的最短渗流路径。为了得到研究区域的渗透特性,本文基于图论管网方法编写渗流计算程序,分别计算了三个主要方向较短渗流路径及最短渗流路径的渗透系数。同时通过对不同尺度不同方向子模型等效方向渗透系数的计算,得到了三维裂隙网络模型渗流的REV大小和等效渗透系数张量,为评价研究区域内裂隙的渗透性奠定了基础。
[Abstract]:A discrete fissure network is formed in fractured rock mass due to the existence of many discontinuous structural planes. The cracks in these rock masses constitute a potential flow path carrying radionuclide fluids. The analysis of fluid flow in rock mass is very important in both geotechnical and hydrological engineering. Due to the complexity of space distribution of fractures in rock mass, the analysis of rock mass permeability is based on the discrete fracture network model generated by Monte Carlo method. In this paper, a large amount of fracture information is obtained from the field survey and survey of the pre-selected site of the high-level radioactive waste disposal depot in Beishan, Gansu Province. The permeability analysis of the measured two-dimensional fracture network model and the seepage path search and permeability characteristic analysis of the three-dimensional fracture network model based on Monte Carlo method are carried out respectively. With the help of the close-range photogrammetry method, the 3D coordinates of crack endpoints on the outcrop surface are obtained and transformed into the local two-dimensional coordinates on the outcrop surface, and the two-dimensional discrete fracture network model of the area is established by the discrete element method. The osmotic ellipse of the three regions is obtained by analyzing the permeability of the three regions, and the osmotic Zhang Liang and the main osmotic value and direction of the osmotic ellipse in the outcrop are obtained. According to the mass density and other fracture information of each block in a large area, the 3D model is established by Monte Carlo method, and the 3D discrete fracture network model, which is in good agreement with the actual fracture distribution, is obtained. Based on VS2010 platform, DFS algorithm is used to get the short seepage path in three main directions of the whole research area, and Dijkstra algorithm in graph theory is used to obtain the shortest seepage path in three main directions. In order to obtain the percolation characteristics of the studied area, the seepage calculation program is compiled based on the graph theory pipe network method, and the permeability coefficients of the shorter and shortest percolation paths are calculated respectively in three main directions. At the same time, by calculating the equivalent directional permeability coefficient of the submodels with different scales and different directions, the magnitude of REV and the equivalent permeability coefficient Zhang Liang of the 3-D fracture network model are obtained, which lays a foundation for evaluating the permeability of fractures in the study area.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45

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