A cracked rock mass can be idealized using a three-set model of orthogonal cracks. By varying the number of cracks per set, the structural anisotropy caused by the cracks is represented, and by rotating the principal axes of the structural anisotropy a more realistic model is constructed following field observations. A constitutive law for closing a crack aperture is formulated based on the results of the extensive laboratory tests previously reported. Parameter , which controls stress-dependent hydraulic behaviors of cracked rock masses, can be determined by a laboratory test, and its mechanical significance is explained as an index of the pseudo-elastic modulus related to crack closing. The value of experimentally determined highly depends on the number of loading cycles and whether it is loading or unloading. Information regarding the stress history is required to estimate for cracks in the field. The depth-dependent hydraulic conductivity tensor for a cracked rock mass is formulated in a closed form, in which the effects of structural anisotropy, non-hydrostatic stress, and rotation of crack system are considered. If the stress field is hydrostatic, the hydraulic conductivity tensor exhibits unique depth dependence, despite its structural anisotropy and rotation of its principal axes. Non-hydrostatic stress exerts a significant influence on the hydraulic conductivity tensor. Hydraulic anisotropy is determined by interference among the following three factors: (a) structural anisotropy caused by cracks, (b) non-hydrostatic stress, and (c) discordance between the principal axes of the structure and stress. The importance of the second and third factors is that hydraulic anisotropy cannot be discussed solely in terms of structural anisotropy. The depth-dependent mean hydraulic conductivity obtained by the current theory corresponds well with field measurements at two sites.

中文翻译：

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深度达 1,000 m 的裂隙岩体导水率张量


可以使用正交裂缝的三组模型来理想化破裂的岩体。通过改变每组裂纹的数量，表示由裂纹引起的结构各向异性，并通过旋转结构各向异性的主轴，根据现场观察构建更真实的模型。根据先前报告的大量实验室测试的结果，制定了闭合裂纹孔径的本构定律。控制裂纹岩体与应力相关的水力行为的参数 可以通过实验室试验确定，其力学意义被解释为与裂纹闭合相关的拟弹性模量的指标。实验确定的值很大程度上取决于加载循环的次数以及加载还是卸载。需要有关应力历史的信息来估计现场的裂缝。裂隙岩体与深度相关的导水率张量采用封闭形式，其中考虑了结构各向异性、非静水应力和裂隙系统旋转的影响。如果应力场是静水应力场，则水力传导率张量表现出独特的深度依赖性，尽管其结构各向异性和主轴旋转。非静水应力对导水率张量有显着影响。水力各向异性是由以下三个因素之间的干扰决定的：（a）由裂缝引起的结构各向异性，（b）非静水应力，以及（c）结构主轴与应力之间的不一致。第二个和第三个因素的重要性在于，水力各向异性不能仅从结构各向异性的角度来讨论。 通过当前理论获得的与深度相关的平均导水率与两个地点的现场测量吻合良好。