不同填充及加载路径下劈裂砂岩渗流特性研究

采用劈裂宜昌砂岩，对中细砂、粗砂及混合砂砂粒填充条件下加载路径、轴压、围压、填充物颗粒粒径及填充物厚度对渗流速度的影响规律进行探讨。研究结果表明，在不同填充物一定的应力情况下，加力路径发生变化，渗流速度也发生变化，这是工程中测量渗流数据离散的原因之一；轴压与渗流速度成线性关系，当围压?3≤1.5 MPa时，围压对渗流的影响较大，当?3＞1.5 MPa时，围压对渗流的影响极小；粒径与渗流速度呈单调递增关系，围压对无填充物的影响大于对有填充物的影响；渗流速度与填砂厚度在一定范围内呈现指数递增关系、研究中给出特定条件下轴压围压与渗流速度的定量分析公式。

Research on seepage characteristics of splitting sandstone in different fillers and loading paths

The splitting sandstone from Yichang is taken as the research object. The authors make a study of the seepage velocity variation rules caused by different loading paths, axial compressions, confining pressures, particle diameters of filler and filler thickness, when the splitting sandstones are respectively filled by medium-fine sand, coarse sand and mixed sand. The rsearch results show that under different fillers and a certain stress, the seepage velocity changes with the loading path, which is one of the reasons for discreteness of seepage data measured in projects. The axial compression and seepage velocity are in linear relation; while the low confining pressure has a greater impact on the seepage velocity, but the high confining pressure has smaller effect. The particle size is positively correlated with the seepage velocity; and confining pressure has a larger influence on the non-filler sandstone than on the filled one. The seepage velocity and the filler thickness are in an increasing exponentially relationship within a certain range. The research also gives a quantitative analysis formula of axial compression, confining pressure and the seepage velocity in specified conditions.