土中三维裂隙网络渗流的数值模拟

发布时间：2018-06-10 15:10

本文选题：数值模拟 + 边界元法　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：土中存在的裂隙网络影响了水在土体中的运动，进而影响了土体的渗透以及强度等特性。通常可以采用试验的方法来研究裂隙网络渗流的特性，但是在室内或者室外的试验研究中，土样容易受到扰动，并且土样的尺寸也会受到试验条件的限制。因此，本文采取数值模拟的方法对裂隙网络渗流进行研究。本文对裂隙网络的一些性质做了如下假设：单个裂隙的两个裂隙面为不透水的平面，并且两个裂隙面是相互平行的，裂隙的宽度在裂隙面的范围内是固定值，两个裂隙面之间没有任何填充物，水可以自由流动，同时忽略水在垂直于裂隙面的方向上的流动，因此单裂隙可以看作一个沿裂隙面的方向，二维各向同性的介质；不考虑交线上水头损失，交线上的水头值唯一。本文分析了单裂隙渗流的假设条件，，根据单裂隙渗流的控制方程以及边界条件，采用边界元法原理对单裂隙进行边界离散，建立了单裂隙的边界积分方程，给各节点赋予了边界条件，计算了系数矩阵中的各个元素，并求解了矩阵方程，得到了各节点的水头值或流量值。根据交线上水头唯一以及流量平衡两个条件，结合边界元法，计算了两个相交裂隙的渗流，得到了相交裂隙每个节点的水头值或流量值。根据对单裂隙、两个相交裂隙的分析，结合边界元法在裂隙网络渗流计算中的原理，本文编写了三维裂隙网络渗流的计算程序。程序包含了：裂隙网络的离散、系数矩阵的计算、边界条件的设置和求解矩阵方程四部分，每一部分都做了详细叙述。并且，采用一个简单算例对编写的程序进行了验证。本文采用编写好的程序，计算了不同形状的裂隙网络的流量，得到了矩形裂隙网络、三角形裂隙网络、梯形裂隙网络和混合形状裂隙网络的流量值，并对最终结果做了适当分析。
[Abstract]:The fracture network exists in the soil , which affects the movement of the water in the soil mass , which affects the permeability and strength of the soil .

In this paper , some properties of the fracture network are assumed as follows : the two fissured surfaces of a single slit are non - permeable planes , and the two fracture surfaces are mutually parallel , the width of the fracture is fixed in the range of the fracture plane , the water can flow freely , and the flow of the water in the direction perpendicular to the fracture surface is neglected , so that the single slit can be regarded as a medium in the direction of the fracture surface and the two - dimensional isotropic medium ;
The water head loss on the intersection line is not taken into account , and the water head value on the intersection line is unique .

In this paper , the assumption condition of single fracture seepage is analyzed . According to the control equation and boundary condition of single fracture seepage , the boundary integral equation of single fracture is established by using the boundary element method . The boundary integral equation of single crack is established . The boundary conditions are given to each node , and the water head value or flow value of each node is calculated . According to the unique and flow equilibrium condition of the water head on the intersection line , the seepage of two intersecting fractures is calculated , and the head value or flow value of each node is obtained .

Based on the analysis of single fracture and two intersecting fractures and the principle of boundary element method in the calculation of fracture network seepage , this paper develops the calculation procedure of three - dimensional fracture network seepage . The procedure includes : the dispersion of fracture network , the calculation of coefficient matrix , the setting of boundary conditions and the four parts of solving matrix equation .

In this paper , the flow of fracture networks with different shapes is calculated by using the written procedure , and the flow values of the rectangular fracture network , the triangular fissure network , the trapezoid fracture network and the mixed shape fracture network are obtained , and the final results are analyzed .
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU411

【相似文献】