| 考虑应力历史的岩石单裂隙渗流特性试验研究 |
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| 引用本文： | 杨金保,冯夏庭,潘鹏志.考虑应力历史的岩石单裂隙渗流特性试验研究[J].岩土力学,2013,34(6):1629-1635. |
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| 作者姓名： | 杨金保 冯夏庭 潘鹏志 |
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| 作者单位： | 1.中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室，武汉 430071；2.长江三峡勘测研究院有限公司，武汉 430010 |
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| 基金项目： | 国家自然科学基金资助项目 |
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| 摘 要： | 通过开展单裂隙花岗岩不同围压加、卸载和不同水力梯度作用下的渗透试验，研究应力历史对裂隙渗透性能演化的影响。试验结果表明：在围压加载过程中，渗流流量与渗透压差大致呈线性关系；在渗透压差相同的条件下，围压越小，流量越大，随着围压上升，裂隙渗流流量持续减小，但随着围压的进一步增大，流量的减小有减缓的趋势。在围压相同以及渗透压差相同的条件下，单裂隙花岗岩在卸载条件下的渗流特性与加载条件下相比，其渗流流量明显降低，且卸载过程中渗流流量与渗透压差开始偏离线性关系。从试验前、后裂隙面粗糙度系数值的对比可以看出，由于法向应力挤压以及渗流流体的冲蚀作用，试验后裂隙面粗糙度系数明显降低。卸载的过程中，裂隙渗透性能的恢复具有明显的滞后效应，表明在法向应力和流体冲蚀的共同作用下，裂隙产生了不可恢复的非弹性变形。
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| 关 键 词： | 岩石单裂隙 岩石渗透性 裂隙粗糙度 应力历史 加卸载 |
| 收稿时间： | 2012-03-12 |
Experimental study of permeability characteristics of single rock fracture considering stress history |
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| YANG Jin-bao、,FENG Xia-ting、,PAN Peng-zhi、.Experimental study of permeability characteristics of single rock fracture considering stress history[J].Rock and Soil Mechanics,2013,34(6):1629-1635. |
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| Authors: | YANG Jin-bao、 FENG Xia-ting、 PAN Peng-zhi、 |
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| Institution: | 1.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; 2. Three Gorges Survey and Research Institute Co., Ltd., Wuhan 430010, China |
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| Abstract: | Seepage tests under different loading and unloading confining pressures and different hydraulic gradients are conducted on single granite fracture to study the effects of stress history on fracture permeability evolution. Experimental results show that during loading process, flowrate is approximately linear with hydraulic gradient; under the same hydraulic gradient, flowrate decreases with the increase of confining pressure at a step-down rate, but with further increase of confining pressure, the reducing amplitude of the flow becomes smaller and smaller. Under the same confining pressure and hydraulic gradient, the flowrate of the single granite fracture deceases obviously during unloading process compared with that during loading process. Furthermore, flowrate is no longer linear with hydraulic gradient during the unloading process of confining pressure. Comparison between roughness coefficients before and after test shows that, joint roughness coefficient(JRC) of the fracture after test decreases dramatically due to the normal compression and scouring of the seepage fluid. Obvious hysteresis of fracture permeability recovering is also observed, indicating inelastic deformation of the fracture occurs under combined effects of normal stress and fluid scouring. |
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| Keywords: | rock single fracture rock permeability joint roughness coefficient stress history loading-unloading |
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