| 刘 杰,李建林,屈建军,张玉灯.宜昌砂岩轴压致裂和人工裂纹下的渗流试验研究[J].水利学报,2010,41(12): |
| 宜昌砂岩轴压致裂和人工裂纹下的渗流试验研究 |
| Experimental study on seepage in cranny of sandstonedue to axial compression and artificial fracture |
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| DOI： |
| 中文关键词: 砂岩 渗流试验 人工切割裂隙 原岩压裂 加载路径 |
| 英文关键词: sandstone seepage test manual cutting fracture original rock fracturing loading path |
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| 中文摘要: |
| 对受轴向压缩荷载致裂的宜昌地区砂岩，通过试验研究轴压、围压、裂隙几何尺寸和岩性等因素对渗流量的影响。对于压裂的泥质砂岩，裂隙深度 （对应受力面积） 与开度比值越大，试件的渗流量受围压影响就越大，轴压与渗流量呈非线性关系；对于钙质中细砂岩，其流速随围压的变化显得波动很大，规律性较差，而在围压恒定时，轴压与流速呈二次抛物线的非线性关系；对于钙质粗中砂岩，围压越大，其渗流流速与轴压的关系越接近于直线。与无填充人工切割裂隙和填充人工切割裂隙的渗流成果进行对比分析，研究表明：无填充人工切割裂隙渗流量与轴压呈线性关系，主要是由于渗流断面积过大引起。填充人工切割裂隙的渗流试验表明，砂粒在没有冲紧密实之前其渗流量测量数据是没有可重复性的，不但受到轴压的加载路径影响，还受到围压的加载路径影响。人工裂隙中有砂充填密实后，轴压和流速仍呈线性关系。对砂岩轴压产生的裂纹，在0~1MPa的过渡过程中，渗流量迅速衰减 （二次项系数衰减可达21/22），衰减量远大于有砂粒填充的有一定开度的人工节理。 |
| 英文摘要: |
| Experiments on sandstones obtained from the Yichang area with artificial fractures were conduct?
ed to investigate the influences of axial compression，ambient pressure，cranny geometry，cranny roughness and lithology etc on seepage. For the fractured argillaceous sandstone，the larger the ratio of cranny depth（corresponding area by force）and opening，the bigger the influences on seepage in specimens under ambient pressure，and the relation between axial compression and seepage is nonlinear. For calcareous sandstone，its flow rates fluctuate greatly with varied ambient pressure in poor regularity，and a nonlinear parabolic relationship between axial compression and flow rate can be found under a constant ambient pressure.For calcareous coarse sandstone，the greater the ambient pressure，the closer the linear relationship between flow rate and axial compression. Comparing the seepages in artificial cutting cranny with and without fillings，the results show that there is a linear relationship between seepage and axial compression，which is mainly because of the excessive section of seepage. Seepage tests in cutting cranny with fillings show that the measured seepage data are not repeatable before the washed sand particles being pressed tightly because of the impacts on loading path not only from the axial compression but also from ambient pressure.When the cutting fracture filled with sand tightly，the relationship between axial compression and flow rate
keeps linearly. For sandstone cracks caused by axial compression，the seepage decays rapidly（quadratic coefficient attenuates to 1/22） in the transition process from 0 to 1 MPa，that is much lower than the case in artificial fracture with a certain opening and filled with sand. |
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