不同垫块包围角度下砂岩劈裂声发射特性试验研究  

Experimental study on acoustic emission characteristics of sandstone splitting under different contact arc angles

作　　者：许晓通 鲁鲲鹏[1] 周瑜 吴道勇 XU Xiaotong;LU Kunpeng;ZHOU Yu;WU Daoyong(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Karst Geological Resources and Environment of Ministry of Education,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025

出　　处：《人民长江》2022年第9期134-139,共6页Yangtze River

基　　金：贵州省科技计划项目(黔科合基础[2021]一般512,黔科合基础-ZK[2022]重点018);贵州大学人才引进科研项目(贵大人基合字[2017]76)。

摘　　要：为研究岩石劈裂试验中不同垫块包围角度对岩石声发射特性的影响,采用包围度数分别为10°,30°,60°的垫块对砂岩圆盘试样进行单轴循环加卸载试验,对比分析试样的声发射特性。试验结果表明:包围度数的增加对砂岩Kaiser效应几乎没有影响,而试样的累计计数、累计能量计数、峰值强度均显著提高,试样由沿荷载直径附近的单一劈裂破坏逐渐演变为沿垫块端部首先局部失效的复杂破坏。在整个循环加卸载过程中,不同包围度数下砂岩声发射b值演化规律总体一致,不同荷载阶段试样内部损伤的程度不同,b值呈现出一定的演化规律。研究成果可为利用Kaiser效应测量地应力及岩石破裂过程分析提供试验支撑。To study the influence of contact area between the steel spacers and specimen on the acoustic emission(AE)characteristics of rock samples,a series of uniaxial loading and unloading tests were performed to analyze the AE characteristics of the sandstone disc specimen with contact arc angle of 10°,30°,and 60°.The results showed that with the increase of the contact angle,Kaiser effect was not influenced,however accumulative AE count,accumulative AE energy count,peak strength were clearly improved,while the specimens′failure mode was transformed from a single splitting failure at the load diameter vicinity to a complex failure of contact end breaking firstly.During the cyclic loading and unloading test,the evolution law of the AE b-value of the sandstone under different contact areas was generally consistent.The degree of the internal damage of the specimen at different loading stages was different,and the b-value showed a certain evolution law.The results can provide experimental proof for the measurement of the ground stress by using the Kaiser effect as well as analysis of rock failure process.

关 键 词：砂岩圆盘试样 垫块包围度数 B值 声发射 KAISER效应 

分 类 号：TU459[建筑科学—岩土工程]