注水诱发地震中含不同断层泥的断层岩石破坏研究  

Rock failure of faults with different fault gouges in injection induced earthquake

作　　者：康建旗 姜智彬 吴振宇 郑东平 朱建波 KANG Jianqi;JIANG Zhibin;WU Zhenyu;ZHENG Dongping;ZHU Jianbo(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China;The 5th Engineering CO.Ltd.,China Railway 25th Bureau Group,Qingdao 266000,China;Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization,Institute of Deep Earth Sciences and Green Energy,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300350 [2]中铁二十五局集团第五工程有限公司,山东青岛266000 [3]深圳大学广东省深地科学与地热能开发利用重点实验室,深地科学与绿色能源研究院,土木与交通工程学院,广东深圳518060

出　　处：《中南大学学报（自然科学版）》2021年第8期2702-2712,共11页Journal of Central South University:Science and Technology

基　　金：国家重点研究计划项目(2018YFC0407002);国家自然科学基金资助项目(51974197);广东省引进创新创业团队项目(2019ZT08G315)。

摘　　要：为了探究断层泥在注水诱发断层滑动中的作用机制及断层周边岩石的破坏程度,选取3种不同成分断层泥的断层(断层1中断层泥由75%石英砂和25%蒙脱石组成;断层2中由50%石英砂和50%蒙脱石组成;断层3中由25%石英砂和75%蒙脱石组成),开展室内高压注水双轴加载试验,研究注水诱发地震中含不同断层泥的断层滑动特征。采用验证后的COMSOL数值模型并结合岩石损伤理论,分析断层泥对平直和交叉断层周边岩石变形破坏的影响规律。研究结果表明:注水条件下含高强度(剪切)断层泥的断层不易发生失稳滑动,但滑动后易产生较大震级的诱发地震(应力降大),导致断层周边岩石出现大面积变形破坏区;断层周边岩石变形破坏区域的分布方位受断层泥的影响甚微,主要由断层几何结构控制;平直断层周边岩石的变形破坏区域分布在断层两端,交叉断层周边岩石的变形破坏区域主要分布在断层连接处及次断层端部,当交叉角度为45°时,交叉断层周边岩石破坏程度最低。In order to explore the effect of fault gouges on the fault slip induced by water injection and the rock failure around the fault.Firstly,three kinds of faults with different fault gouges were selected(Fault 1 with 75%quartz and 25%montmorillonite;Fault 2 with 50%quartz and 50%montmorillonite;Fault 3 with 25%quartz and 75%montmorillonite).Then,through laboratory biaxial loading test,the characteristics of fault slip with different fault gouges were studied in injection-induced earthquake.Finally,based on COMSOL numerical model verified by test results and the rock damage theory,the rock failure around straight and crossed faults with the different fault gouges were analyzed.The results show that under the condition of water injection,the fault gouge with high shear strength makes the fault not easy to slide,but after sliding,it will produce a large earthquake magnitude(owing to large stress drop),which leads to a large area of rock failure around the fault;the distribution direction of the area of the rock failure around the fault is little affected by fault gouges,which is mainly controlled by the geometry structure of faults.The failures surrounding the straight fault are distributed at both ends of the fault;the failure areas surrounding cross faults are mainly distributed at the joint of faults and the end of secondary faults;when the crossing angle is 45°,the rock failure around the cross fault is the lowest.

关 键 词：注水诱发地震 断层泥 交叉断层 岩石破坏 

分 类 号：P642.3[天文地球—工程地质学]