【作者】 张莉丽；

【导师】 于青春；

【作者基本信息】 中国地质大学（北京） ， 地下水科学与工程， 2011， 博士

【摘要】 裂隙岩体的渗透性是水文地质学的重要研究内容之一,许多工程和研究领域都与裂隙岩体渗流有着密切的联系。本文基于非连续裂隙网络渗流分析,系统研究各种类型裂隙岩体典型单元体(REV)的存在性及大小。根据岩石裂隙迹线长度,国际岩石力学学会将裂隙岩体分为五种类型,此外根据裂隙间距又分为七种裂隙岩体。两种分类方案排列组合,裂隙岩体共有35种类型。论文运用作者所在的课题组开发的非连续裂隙网络渗流分析软件FractureToKarst模拟了这些类型岩体的裂隙网络,并进行岩体渗透性分析。在模拟时,固定每个区域的水力梯度为1,长宽比为2:1,每旋转10°计算一个等效渗透系数,这样可以得到36个方向上的等效渗透系数,从中选出可以看作均质介质的最小区域。然后讨论其方向等效渗透系数,在极坐标下是否能够被拟合成一个渗透性椭圆,从而确定此种类型裂隙岩体典型单元体的存在性及大小。模拟结果表明:(1)非常低延展性裂隙岩体的REV,只有在裂隙间距小于200mm的条件下才会存在;低延展性裂隙岩体和中等延展性裂隙岩体的REV,只有在裂隙间距小于600mm的条件下才会存在;高延展性裂隙岩体的REV,只有在裂隙间距小于4000mm的条件下才会存在;非常高延展性裂隙岩体的REV,只有在裂隙间距小于6000mm的条件下才会存在;(2)裂隙岩体REV的存在性与裂隙的几何参数有密切的关系。迹长、间距、隙宽、倾向、倾角等发生变化时,裂隙岩体的REV也会发生变化;(3)同种延展性的裂隙岩体,裂隙间距越小,REV存在的可能性越大,并且REV的尺寸越小;(4)同种间距的裂隙岩体,裂隙延展性越高,REV存在的可能性越大,并且REV的尺寸越小。更多还原

【Abstract】 Permeability of fractured rock mass is one of the importent content of hydrology. Many projects and studies have a good relation with fluid flow in fracture rock mass. This paper based on seepage theory of discrete fracture network and propses a general method which determines the existence of REV.The ISRM divides the fracture into five classes according to their trace length and seven classes according to their distances and there are thirty-five classes after such a classification and using the software simulates these fracture rock masses. Survey regions fixed hydraulic gradient 1 and fixed length-width ratio 2:1 are also rotated in 10°intervals to calculate the equivalent permeability. And then 36 equivalent permeabilities in different orientations will be got in each region in order to evaluate a the smallest size.And whether or not the 36 permeablities can be plotted as a permeability ellipse in polar coordinates and REV is discussed and determined.By the study of the fracture rock mass, the major results are as follows:(1) REV is exists in the very low tractility frcture rock mass,only when their fracture spacing is less than 200 mm; REV is exists in the low tractility and the medium tractility fracture rock mass,only when their fracture spacing is less than 600 mm; REV is exists in the very high tractility fracture rock mass,only when their fracture spacing is less than 4000 mm;REV is exists in the high tractility fracture rock mass,only when their fracture spacing is less than 6000 mm.(2) The fracture rock mass REV existence has a close relationship with fracture geometric parameters. REV will change when trace length,space,distance, dip, angle of dip etc..(3) The same tractility fracture rock mass, the spacing is smaller, the REV existence’s possibility is bigger, and the REV size is smaller.(4) The same spacing fracture rock mass, the tractility is higher, the REV existence’s possibility is bigger, and the REV size is smaller.更多还原