劈裂砂岩有、无砂粒填充条件下的多因素对渗流量影响对比分析

采用宜昌劈裂砂岩,在有、无砂岩填充条件下,分别从轴压、围压、劈裂面面积、凹凸高差、迹线长度、劈裂面2D投影面积、进出口长度、结构面粗糙度对渗流量的影响规律进行了对比分析。研究结果表明:有、无砂粒填充下轴压与渗流量均呈线性递增关系;无填充时围压与渗流量呈对数递减关系,有充填时围压与渗流量呈线性关系;无充填时渗流量与流面积呈三次函数关系,而充填后过流面积对渗流量几乎无影响;凹凸高差、2D面积与渗流量的关系也有相似规律,分析认为,这主要是砂粒充填后带来的过流通道要远大于上述三因素对过流通道的改变;无充填时,渗流量随迹线长度线性递减,有填充时该规律被淹没;无论有、无填充,渗流量与过流面粗糙度系数在一定范围内均呈现二次函数关系。这些规律能指导渗流测量时各因素的优先次序,可有效减少对次要影响因素的测量工作,同时可对渗流的数值模拟提供参考。

Comparative analysis of multiple factors affecting seepage flow of splitting sandstone with fillers or non-fillers

Taking the splitting sandstone from Yichang as the research object, the paper respectively studies about seepage flow variation rules caused by axial compressions, confining pressures, splitting surface area, concave-convex height different, trace length, 2D projected area of splitting surface, import and export length and joint roughness. The results suggest that the axial compression and seepage flow are in linear increasing relation whether the specimen is filled or not; confining pressures and seepage flow are in a relationship of logarithmic decrement when the specimen is unfilled, while in linear relation as the specimen is filled. Under non-filler condition, the seepage area has a cubic function to the seepage velocity, while there is no influence under filling condition, and at the same time, the concave-convex height difference, 2D projected area have the same rule with seepage velocity. Analysis suggests that the influence on seepage passages of the three factors is far from that caused by fillers; under non-filler condition, the trace length reduces linearly with the seepage velocity; the joint roughness coefficient shows a quadratic functional relationship with the seepage flow whether the specimen is filled or not. These rules can guide the priorities of factors in the seepage measurement, and effectively reduce the measurement of those secondary factors and provide a reference for numerical simulation of seepage.