基于实测结构面的岩体渗流特性分析

Analysis of Seepage Characteristics of Rock Mass Based on Measured Structural Plane

通过数字化量测方法,现场实测了建立结构面网络所需的参数,如迹长、空间三维坐标等。将获得的结构面空间三维坐标转化为二维坐标,采用离散单元方法定量地进行渗流分析,主要的工作包括:根据实测的结构面参数、迹长与隙宽的关系,确定不同裂隙的隙宽,从而建立结构面网络模型;计算了实测结构面中所选研究区域不同方向的等效渗透系数(5.4416×10^(-6)~9.7611×10^(-6)m/s),将获得的渗透系数绘制在极坐标系中,获得了岩体渗流的主渗透方向。根据渗透椭圆在三维空间中的分布,分析发现主渗透方向向左偏离正北方向约63°~78°,而另一等效渗透系数比较大的方向向左偏离正北方向约18°~33°,与实测露头面中两组夹角约为60°~70°优势裂隙组的方位一致,验证了采用实测结构面进行数值模拟的合理性。

Through using the digital measurement method, the parameter to build structural plane network is measured in situ, such as the trace length, three dimensional coordinates and etc. The obtained three dimensional structural plane coordinates are converted into two dimensional coordinates, then the discrete element method is used to analyse the seepage quantitatively. The main jobs are as follow： According to the relationship between parameters of measured structural plane,the trace length and gap length, the aperture width of different fracture are determined. From this the structural plane network model is established and the equivalent permeability coefficient （ 5. 4416 × 10 -6 - 9. 7611 × 10 -6 m/s） are calculated for different directions in this area selecting the measured structural plane. Which are plotted in polar coordinate system and the principal seepage direction of rock is obtained. It is found that the principal seepage direction deviates from the left due north about 63° -78°, while another relatively large equivalent permeability coefficient deviates from the left due north about 18° -33°, which are same with the direction of two advantageous sets of joints that the angle between them is about 60° - 70°on the basis of the distribution of permeability ellipse in three-dimensional space. The results show that this method is reasonable for the numerical simulation of measured structural plane.