花岗岩压剪破裂扩展及声发射b值的法向力影响特征  

The influence study of normal force on the crack propagation of granite and the b-value of acoustic emission

作　　者：刘祥鑫[1,2] 吴立新 吕欣[4] 毛文飞 张艳博 LIU Xiangxin;WU Lixin;LYU Xin;MAO Wenfei;ZHANG Yanbo(College of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;College of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Modern Technology and Education Center,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819 [2]华北理工大学矿业工程学院,河北唐山063210 [3]中南大学地球科学与信息物理学院,湖南长沙410083 [4]华北理工大学现代技术教育中心,河北唐山063210

出　　处：《中国矿业》2019年第12期128-132,共5页China Mining Magazine

基　　金：国家自然科学基金青年基金项目资助(编号：51604117);国家自然科学基金面上项目资助(编号：51774138);河北省科技计划项目资助(编号：15273908)

摘　　要：岩石作为各类地下隧洞、边坡等工程的基础介质,其稳定性已成为领域中的关键问题。工程岩体较易出现复杂的剪切破坏,除受应力边界条件影响以外,还与破坏尺度及裂隙分布密切相关。基于声发射监测技术,开展不同法向力的岩石剪切破坏实验,研究裂隙的分布及扩展方式,获取岩石最终失稳破裂的前兆特征信息。研究结果表明,剪切力峰值和雁列倾角均与法向力呈正相关;岩石剪切破坏过程中主裂隙为雁列,由主剪切力产生,局部尺度的羽列裂隙则由次生剪切力产生;b值的突然下降意味着岩石出现了大能量的破坏,连续且异常的低b值可作为岩石剪切破坏的有效前兆特征。As the basic medium for various underground tunnels and slopes,rock stability has become a key issue in field of underground engineering research.Engineering rock masses are more prone to complex shear failures.In addition to the stress boundary conditions,it is also closely related to the damage scale and fracture distribution.Based on the acoustic emission technology,the rock shearing experiment under different normal force has been carried out.A research on the distribution and expansion of fracturing has been conducted,and the precursor feature information of the rock final instability has been obtained.The results demonstrate that there exists positively correlated with normal force and shearing force and the angle of echelon crack;the echelon crack is the main crack which is produced by the main shearing force,and the local scale of pinnate is generated by the secondary shearing force;the suddenly decreased of b-value means that some higher-energy crack has been occured during the rock shearing process;the continuous and abnormal lower b-value can be regarded as an effective precursor of rock shearing failure.

关 键 词：剪切破坏 法向力 声发射 B值 

分 类 号：TU45[建筑科学—岩土工程]