Study on groundwater flow and transport properties considering the structural change of fracture system in rock masses.

考虑岩体裂隙体系结构变化的地下水流输运特性研究

基本信息

批准号：
07454119
负责人：
WATANABE Kunio
金额：
$ 4.35万
依托单位：
Saitama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454119/
关键词：
rock masses fluid flow path fracture system permeability test groundwater 割れ目の可視化

项目摘要

It is commonly accepted that fluid flow in granitic rocks mainly occurs through discontinuities such as joints, fractures and cracks. However all of discontinuities are not always the conduits. How do the fluid flow path form? The investigations of fracture system in Stripa mine, Aspo Hard Rock Laboratory and Kamaishi Mine suggest that fluid flow path mainly relates to the displacement along the fractures and in situ stress regime.The effect of shear deformation on hydraulic properties of Miocene sandstone, Shirahama Ss, was investigated in drained triaxial compression experiments. Flow pump method developed by Olsen et al. (1985) is adopted in order to measure the hydraulic conductivity. The water to permeate was run out to two directions, that is the loading direction and the vertical to loading. These tests show that hydraulic conductivities at the peak stress for both tests increase about three times as large as the initial ones. The difference of hydraulic properties due to flow direction is now in consideration.In order to examine the deformational and hydraulic properties of rock with fracture system, we developed the triaxial testing machine, in which the surface microstructure of specimen can be observed in a motion using a stereoscopic microscope. In this present study we first showed some experimental results in uniaxial compression test. The shearing process on fractures experimentally generated is simultaneously observed by stereoscopic microscope. The rotation and cutting of bridge, sliding on fracture plane and opening of fracture occur. Furthermore it is clear that these structures are continued inside the specimen by thin section observation. Next, permeability tests under triaxial compression were conducted for fractured Shirahama sandstone. The tests show that the slide along fractures mainly occur after the peak stress and hydraulic conductivity abruptly increase.

通常认为，花岗岩岩石中的流体流主要通过关节，断裂和裂缝等不连续性发生。但是，所有的不连续性并不总是是管道。流体流动路径如何形成？对条纹矿场，ASPO硬岩实验室和卡马西矿的裂缝系统的研究表明，流体流动路径主要与沿裂缝和原位应力状态的位移有关。剪切变形对中新世砂岩的水力特性，Shirahama，Shirahama，Shirahama，Shirahama，Shirahama，Shirahama SS的影响。 Flow Pump方法由Olsen等人开发。（1985）是为了测量液压电导率。渗透的水被用光到两个方向，即负载方向和垂直载荷。这些测试表明，这两种测试的峰值应力下的液压电导率大约是初始测试的三倍。现在考虑到由于流动方向引起的液压特性的差异。在本研究中，我们首先在单轴压缩测试中显示了一些实验结果。实验产生的裂缝上的剪切过程通过立体显微镜同时观察到。桥梁的旋转和切割，在断裂平面上滑动以及裂缝的打开。此外，很明显，通过薄截面观察，这些结构在样品内部继续。接下来，针对骨折的Shirahama砂岩进行了三轴压缩下的渗透性测试。测试表明，沿裂缝的载玻片主要发生在峰值应力和液压电导率突然增加之后。