三维裂隙网络线单元渗流模型及其校正

发布时间：2018-11-08 13:15

【摘要】：裂隙岩体渗流研究对于许多应用学科的进一步发展具有重要意义,同时也是解决一些重大实际工程问题的迫切需求,例如水利水电工程、土木工程、石油工程、核电工程以及矿产资源开采等相关工程领域。岩体的水力学性质主要由岩体内分布的结构面控制,结构面是指地质历史发展过程中,在岩体内形成的具有一定延伸方向和长度、厚度相对较小的地质界面或带。由于岩体内结构面的形状、产状和大小不同,空间组合形式也不同,使岩体渗透性表现出各向异性和非均质性。这也决定了岩体水力学参数的取值和渗流分析是一个极其复杂、而又极具实际意义的研究课题。如何合理的表示这种非均质性是研究的重点和难点。针对这种非均质性,可以将岩体渗流模型概括为四类：等效连续介质模型、双重介质渗流模型、离散裂隙网络模型、混合模型。等效连续介质模型相对已经比较成熟,但是裂隙岩体代表单元体的大小和等效水力参数较难确定,同时其不能很好地刻画裂隙的特殊导水作用。后两种方法更能刻画裂隙岩体渗流的基本规律和体现岩体的非均质性,具有广泛的发展空间。混合模型虽然能更为全面反映裂隙岩体渗流特征,但难以确定结构体和裂隙面之间的水量交换关系,使其使用价值具有很大的局限性。因此,本文主要致力于发展既能最大程度符合客观规律又兼具实际工程应用价值的离散裂隙渗流模型。对于岩体渗流来说,离散型裂隙网络比等效连续型裂隙网络更能准确而客观地刻画实际岩体中的渗流规律。本文依据现场测量所获得的裂隙产状统计规律,利用Monte Carlo法模拟生成相应的裂隙网络,采用图论数学模型中深度优先搜索(DFS)方法完成裂隙网络最大连通分量的确定。本文依据裂隙间的相交关系,将岩体渗流网络概化为以裂隙圆盘圆心为结点,相交圆盘圆心间连线为单元的三维裂隙网络线单元模型。此方法将三维裂隙渗流网络简化为空间一维渗流网络,大大减少了渗流模型的结点数与单元数,极大地减少了渗流计算量。与管道渗流模型对比分析,对相关算例进行模拟计算,得到模型的等效渗透张量和流量。
[Abstract]:The study of seepage in fractured rock mass is of great significance to the further development of many applied disciplines, and is also an urgent need to solve some important practical engineering problems, such as water conservancy and hydropower engineering, civil engineering, petroleum engineering, etc. Nuclear power projects and mining mineral resources and other related engineering areas. The hydraulic properties of rock mass are mainly controlled by the distribution of the structural plane in the rock body. The structural plane refers to the geological interface or zone formed in the course of geological history which has a certain extension direction and length and relatively small thickness in the rock mass. Due to the different shape, occurrence and size of the structural plane in the rock body and the different spatial combination forms, the permeability of the rock mass shows anisotropy and heterogeneity. This also determines that the determination of hydraulic parameters and seepage analysis of rock mass is an extremely complex and practical research topic. How to reasonably express this heterogeneity is the focus and difficulty of the research. In view of this heterogeneity, the seepage model of rock mass can be divided into four categories: equivalent continuum model, double medium seepage model, discrete fissure network model and mixed model. The equivalent continuum model is relatively mature, but it is difficult to determine the size and equivalent hydraulic parameters of fractured rock mass, and it can not well describe the special hydraulic conductivity of fracture. The latter two methods can describe the basic law of seepage in fractured rock mass and reflect the heterogeneity of rock mass, so they have extensive development space. Although the mixed model can reflect the seepage characteristics of fractured rock mass more comprehensively, it is difficult to determine the water exchange relationship between the structural body and the fracture surface, which makes its use value very limited. Therefore, this paper is mainly devoted to the development of discrete fracture seepage model, which can accord with the objective law to the greatest extent and has practical application value. For the seepage of rock mass, the discrete fracture network is more accurate and objective than the equivalent continuous fracture network to describe the seepage law in the actual rock mass. In this paper, according to the statistical law of fracture occurrence obtained by field measurement, the corresponding fracture network is simulated by Monte Carlo method, and the maximum connected component of fracture network is determined by depth first searching (DFS) method in graph mathematical model. In this paper, according to the intersecting relationship between fractures, the seepage network of rock mass is generalized as a three-dimensional fracture network line element model with the center of the fissure disk as the node and the line between the intersected disc centers as the element. In this method, the three-dimensional fracture seepage network is simplified into a spatial one-dimensional seepage network, which greatly reduces the number of nodes and elements of the seepage model, and greatly reduces the amount of seepage calculation. By comparing and analyzing the seepage model of pipeline, the equivalent permeability Zhang Liang and flow rate of the model are obtained.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU452

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