剪切荷载作用下砂岩断裂面粗糙度三维统计分析

Three Dimensional Statistical Analysis of Fracture Roughness of Sandstone Under Shear Loading

利用自主研发煤岩剪切-渗流耦合实验装置与三维立体扫描仪对剪切荷载作用下砂岩断裂面粗糙度三维统计信息进行了实验研究,从其断裂面扫描直观图、断裂面等高线分布图、断裂面剖面轮廓线等方面探讨了剪切荷载作用下砂岩断裂面三维粗糙度分布特性.结果表明:砂岩在剪切荷载作用下发生断裂破坏时,其变形特性曲线变化趋势一致,断裂面直观特征存在个体差异,但断裂面粗糙高度分布均近似于正态分布;沿剪切方向与垂直于剪切方向剖面轮廓线特征不同,不能反映断裂面整体特征;分析了粗糙度参数JRC,RL与RS之间关系,JRC值与RL值之间呈近似线性关系,RS值与JRC平均值线性拟合度相对于JRC与RL值线性拟合度更好,JRC平均值更能反映断裂面整体三维特征.

Th e characteristics of fracture roughness of sandstone under shear loading werespecifically discussed through the fracture surface scanning visualmap , contour m a p of thedistribution of the fracture surface and the fracture surface profile contour, according to the 3 Dinformation of fracture roughness of sandstone under shear loading collected by self-developed coalor rock shear-flow coupling test device and 3D scanners. It is showed that the deformationcharacteristic curves generally were in good agreement, the visual features of fracture surface weredifferent from each other, and the distribution of roughness heights was appromiately accordedwith normal distribution. Characteristics of profile along the shear direction and perpendicular tothe shear direction are different, and cannot reflect the whole fracture surface features. Theanalysis of roughness parameters relationshipamong RL, RS and JRC suggests that there was alinear correlation between J R C and RS ,and the linearity of ! s and the average value of JRC wasbetter than that of JRC and RL. So the average value of JRC is more suitable to reflect the 3 Dcharacteristics of fracture surface.