垂直贯穿裂缝对坚硬顶板失稳破断的影响特征  

Study on influencing characteristics of vertical penetrating crack on instability and breaking of hard roof

作　　者：王海洋 赵树磊 刘佳亮[1,2] 夏彬伟[3] 李寿龙[4] WANG Haiyang;ZHAO Shulei;LIU Jialiang;XIA Binwei;LI Shoulong(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory Breeding Base of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400030,China;Occupational Health Technical Service Center,Anhui Occupational Disease Prevention Hospital,Hefei Anhui 230022,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学山区桥梁与隧道工程国家重点实验室,重庆400074 [3]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400030 [4]安徽省职业病防治院职业卫生技术服务中心,安徽合肥230022

出　　处：《中国安全科学学报》2020年第1期66-72,共7页China Safety Science Journal

基　　金：国家自然科学基金资助(51804058);重庆市教委科学技术研究项目(KJQN201800729);重庆交通大学引进人才科研启动基金资助(18JDKJC-B005)。

摘　　要：为揭示直贯穿裂缝对坚硬顶板失稳破断的影响特征,在对水力压裂坚硬顶板形成的垂直裂缝形态进行分析的基础上,对含垂直裂缝坚硬顶板的破断步距进行理论分析,进而结合数值模拟,研究坚硬顶板的变形破坏特征及破坏区域分布。结果表明:当未闭合的垂直贯穿裂缝位于一定区间范围时,坚硬顶板的破断步距小于其初始极限跨距;而当坚硬顶板中的水压裂缝已闭合时,两侧块体会向裂缝面方向发生偏转,并沿裂缝面发生剪切滑移,使坚硬顶板易于发生失稳破断。回转块体咬合点区域的拉压复合破坏作用是造成坚硬顶板块体局部失稳、回转加剧和整体破断的主要原因。垂直裂缝面的法向刚度系数越小,坚硬顶板越容易发生变形失稳。相对于已闭合的垂直裂缝,未闭合垂直贯穿裂缝更容易使顶板发生回转变形和失稳破断。In order to reveal influencing characteristics of vertical penetrating crack on instability and breaking of hard roof,theoretical analysis was conducted on breaking span of such hard roof based on analysis of vertical crack ’ s morphology caused by hydraulic fracturing. Then, deformation failure characteristics and damaged area distribution of hard roof were studied by means of numerical simulation.The results show that the breaking span of hard roof is shorter than its initial limited span when open vertical penetrating crack is in certain range. But if crack is closed,two bulks of the hard roof will deflect to crack face and shear slip will take place along it,which makes hard roof easier to break. The tensioncompression destructive effect in biting point area of rotary blocks is a main reason for local buckling,greater rotating degree and roof breaking. The smaller normal stiffness coefficient of vertical crack face is,the easier roof breaking will be. Hard roof with open vertical penetrating crack instead of closed one is more likely be deform and break.

关 键 词：水力压裂 坚硬顶板 垂直贯穿裂缝 破断步距 裂缝面 

分 类 号：X936[环境科学与工程—安全科学]