煤体强度差异对裂缝跨界面扩展影响规律研究  

Study on influence of coal strength difference on crack propagation across interface

作　　者：刘洪杰 马衍坤[1,2,3] 王小岐 周健 LIU Hongjie;MA Yankun;WANG Xiaoqi;ZHOU Jian(Key Laboratory of Safe and Effective Coal Mining,Ministry of Education,Anhui University of Science and Technology,Huainan Anhui 232001,China;Engineering Technology Research Centre for Safe and Efficient Coal Mining,Anhui University of Science and Technology,Huainan Anhui 232001,China;Technology Research and Development Platform of Coal Mine Deep Mining Disaster Prevention Technology,Anhui University of Science and Technology,Huainan Anhui 232001,China;Beijing-Kunming High-Speed Railway Xikun Co.,Ltd.,Chongqing 400020,China;China Railway Tunnel Bureau Group Co.,Ltd.,Guangzhou Guangdong 511400,China)

机构地区：[1]安徽理工大学煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001 [2]安徽理工大学矿山安全高效开采安徽省高校工程技术研究中心,安徽淮南232001 [3]安徽理工大学煤矿深井开采灾害防治技术科技研发平台,安徽淮南232001 [4]京昆高速铁路西昆有限公司,重庆400020 [5]中铁隧道局集团有限公司,广东广州511400

出　　处：《中国安全生产科学技术》2025年第3期119-125,共7页Journal of Safety Science and Technology

基　　金：云南省重点研发计划项目(202303AA080014);国家自然科学基金项目(52227901);安徽省高校杰出青年科研项目(2024AH020001)。

摘　　要：为探究岩煤界面两侧力学性能差异对裂缝跨界面扩展行为的影响,利用自主研制的单面可视煤岩真三轴水力压裂试验系统,对含不同强度煤体的组合体试块开展真三轴水力压裂试验。采用AE与DIC分析方法研究裂缝跨界面扩展过程的声发射和应变场响应规律。研究结果表明:裂缝在低强度煤层扩展过程中缝网展布形态复杂,水压曲线呈现出高频次的锯齿状波动,声发射信号反应较为剧烈;在高强度煤层扩展过程中缝网展布形态相对单一,水压曲线呈现出较低程度的波动,声发射信号反应较为平静。裂缝在扩展过程中两侧会出现明显拉伸与压缩应变局部化区域,应变局部化区域形态与裂缝扩展路径基本一致。随着裂缝跨越岩煤界面进入煤层,裂缝两侧呈现出明显的拉伸与压缩应变局部化带,不同强度煤岩体试块相较起裂时增大了4.29~11.09倍。裂缝两侧应变集中程度也迅速增大,拉应变值和压应变值分别增大了2.07~2.46倍和1.15~5.02倍。研究结果对顶板导向水力压裂技术研究具有重要参考意义。In order to explore the influence of mechanical property difference on both sides of rock-coal interface on the cross-interface propagation behavior of cracks,the true triaxial hydraulic fracturing test was carried out on the composite test block containing coal bodies with different strengths using a self-developed single-sided visible coal-rock true triaxial hydraulic fracturing test system.The acoustic emission and strain field response law of the cross-interface propagation process of cracks were studied by AE and DIC analysis methods.The results show that the distribution pattern of crack network is complex during the process of crack propagation in low-strength coal seams,the water pressure curve presents the high-frequency sawtooth fluctuations,and the acoustic emission signal response is more intense.During the process of crack propagation in high-strength coal seams,the distribution pattern of crack network is relatively simple,the water pressure curve presents a lower degree of fluctuation,and the acoustic emission signal response is relatively calm.There are obvious tensile and compressive strain localization areas on both sides of crack during the propagation process,and the pattern of strain localization area is basically consistent with the crack propagation path.As the crack crosses the rock-coal interface and extends into the coal seam,the obvious localized zones of tensile and compressive strain are observed on both sides of crack,and the test blocks of coal and rock mass with different strength increase by 4.29~11.09 times compared with the crack initiation.The degree of strain concentration on both sides of crack is also noted to rise rapidly,with the tensile and compressive strain values increasing by 2.07~2.46 times and 1.15~5.02 times,respectively.The research results have important reference significance for the research of roof-guided hydraulic fracturing technology.

关 键 词：顶板水力压裂 岩煤界面 岩煤强度差异 声发射分析 数字图像相关方法 

分 类 号：X936[环境科学与工程—安全科学]