渗透水压作用下完整砂岩剪切-渗流耦合试验研究  

Experimental study on shear-seepage of coupled properties for complete sandstone under the action of seepage water pressure

作　　者：彭守建[1,2,3] 谭虎[1,2] 许江[1,2] 刘义鑫[1,2] PENG Shou-jian TAN Hu XU Jiang LIU Yi-xin(l. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, Chin State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam, Chongqing University, Chongqing 400044, China Chongqing Research Institute of China Coal Technology and Engineering Group Corp., Chongqing 400037, China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室,重庆400044 [3]中煤科工集团重庆研究院有限公司,重庆400037

出　　处：《岩土力学》2017年第8期2213-2220,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51304255;No.51474040);中国博士后科学基金资助项目(No.2014M552323);重庆市项目博士后资助(No.Xm2014037)~~

摘　　要：利用自主研发的煤岩剪切-渗流耦合试验装置,开展了渗透水压作用下完整砂岩试件剪切-渗流耦合特征试验研究。结果表明:(1)在恒定渗透水压情况下,法向应力越大,砂岩的抗剪强度越高,法向变形则越小,砂岩的剪切变形过程可分为3个阶段:剪切变形的线性增长阶段、非稳定破裂发展阶段和剪断后的摩擦滑移阶段;(2)在恒定渗透水压情况下,法向应力越小,法向和剪切变形量越大,剪切断面的起伏程度越大,表面次生裂纹发育越明显、发育范围越宽,砂岩的破坏程度越严重;(3)在整个剪切过程中,剪应力出现几次明显的应力降,首次应力降出现在线弹性变化末期,同时伴有水流流出,说明首次应力降是第一条宏观贯通的裂纹所致,且法向应力越大,裂隙越窄,导水能力越差。By using a self-developed shear-seepage coupling experimental device for coal rock, experiments were carried out on sandstone samples to obtain shear-seepage coupled properties under the action of seepage water. The results show that with constant seepage water pressure, the larger normal stress was, the higher shear strength was, but the smaller normal deformation was. Moreover, the shear deformation process of sandstone can be divided into three stages： the linear growth stage, the unstable fracture stage and the friction sliding stage, respectively. In the case of the constant seepage water pressure, as the normal stress decreased, the peak values of normal and shear deformation of specimen increased, and meanwhile the fluctuation of shear section grew. Besides, the surface crack growth became more obvious and widely distributed, and the damage of sandstone was more serious. In the total shear process, there were several apparent value reductions of shear stress. Usually, the first stress reduction occurred at the end of the stage of elastic deformation, and water flowed out at the same time, which means the first stress reduction caused by the first macrocrack is spatial connected. Furthermore, the larger normal stress is, the narrower fracture is and the worse water transmitting ability is. During the whole experimental process, the lower mean flow rate is, the smaller total flow is.

关 键 词：砂岩 渗透水压 剪切-渗流 耦合特征 法向应力 

分 类 号：TU452[建筑科学—岩土工程]