三轴压缩条件下具有层理性页岩的力学性质及声发射演化  

Mechanical Properties and Acoustic Emission Evolution of Layered Shale under Triaxial Compression

作　　者：代航宇 刘建锋[1,2] 林浩 马超[1,2] DAI Hang-yu;LIU Jian-feng;LIN Hao;MA Chao(State Key Laboratory of Hydraulic and Mountain River Engineering,Sichuan University,Chengdu 610065,China;College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,成都610065 [2]四川大学水利水电学院,成都610065

出　　处：《科学技术与工程》2024年第24期10419-10428,共10页Science Technology and Engineering

基　　金：国家自然科学基金(U20A20266);四川省科技攻关项目(2023ZYD0154,2024GJHZ0035)。

摘　　要：为探寻深部不同埋深应力条件下页岩的力学性质和破坏形态,利用MTS 815岩石力学测试系统开展页岩在常规三轴加载下的声发射试验。试验结果表明:60°层理倾角页岩压缩试验中,峰值应力、峰值轴向应变、弹性模量、泊松比与围压大小成正比;莫尔—库仑准则下所使用60°层理页岩的破裂方位角理论值在62°附近,实验值比理论值稍微偏大,整体在62°附近窄幅波动,页岩破裂模式为沿弱面的剪切破坏;页岩试样横向应变系数的改变与膨胀特性有关,10 MPa下,试样体积应变持续增大,岩石体积缩小,60 MPa试样的体积应变达到了-0.31%,岩石体积膨胀。围压越大,试样的膨胀特性越显著;页岩声发射定位点的多少与振铃计数率大小、能率高低具有良好的一致性。围压增加,累计计数和定位点的总量呈减少趋势,最大能率和累计能量随围压增加而减小。To explore the mechanical properties and failure modes of shale under stress conditions at different depths,the MTS 815 rock mechanics testing system was used to conduct acoustic emission tests on shale under conventional triaxial loading.The test results show that peak stress,peak axial strain,modulus of elasticity,and Poissons ratio are proportional to the confining pressure in the shale compression test with 60°bedding angle.The theoretical value of rupture azimuth of 60°laminated shale used under Mohr-Coulomb criterion is near 62°,the experimental value is slightly larger than the theoretical value,and the whole fluctuates narrowly near 62°,and the rupture mode of shale is the shear damage along the weak face.The change of transverse strain coefficient of shale specimen is related to the expansion characteristic.At 10 MPa,the volume strain of specimen continues to increase,and the rock volume shrinks.At 60 MPa,the volume strain of specimen reaches-0.31%,the rock volume expands.The larger the circumferential pressure is,the more significant the expansion characteristic of the specimen is.The number of shale acoustic emission localisation points has good consistency with the ringing count rate and energy rate.The total number of cumulative counts and localisation points show a decreasing trend with the increase of the enclosure pressure,and the maximum energy rate and cumulative energy decrease with the increase of the enclosure pressure.

关 键 词：页岩 层理角度 破裂方位角 力学性质 声发射 

分 类 号：TU458[建筑科学—岩土工程]