开采扰动下逆冲断层滑动面应力场演化特征
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摘要
复杂地质构造与煤矿冲击地压关系密切,也是世界范围内煤矿安全开采的重要课题,断层滑移失稳诱发冲击地压的机理及前兆信息是煤炭安全高效开采的理论前提和重要保障。工作面开采扰动时,以断层滑动面上应力场演化特征为研究对象,通过相似模拟和数值模拟,研究断层滑移失稳时的前兆信息。以义马千秋矿21221工作面为工程背景,建立了F_(16)逆冲断层赋存条件下的水平加载相似材料模型,运用应力监测和声发射监测的手段,分析了开采扰动下断层滑动面切应力的动态演化特征,研究了工作面开采过程中断层面上声发射事件数的分布规律;通过建立断层赋存条件下的工作面开采的数值模型,研究了断层区域岩层裂隙发育情况,分析了断层滑移失稳时切应力分布和能量释放的动态演化特征;通过相似模拟和数值模拟中应力场、声发射和能量场的分布规律,总结了断层滑移失稳的前兆信息。研究结果表明:断层滑动面切应力和声发射分布特征表现出3个不同的阶段,即水平载荷施加阶段,工作面开采阶段和断层滑动失稳阶段。载荷施加阶段,断层滑动面不断积聚能量,声发射事件数激增;工作面开采过程中,断层频繁受开采扰动,正应力与切应力两者变化不同步。开采初期,正应力处于较大值而切应力较小。随着工作面的开采,正应力与切应力的变化情况相反,正应力逐渐降低,切应力逐步增大。工作面接近断层时,断层滑动面切应力表现为逐步降低的过程中陡然增加的特征;断层滑动前期,断层构造在失稳前仍然积聚大量应变能,声发射事件数出现较少或者缺失的现象;当岩层垮落诱发断层滑移失稳时,能量在不断释放;断层区域内声发射事件数则在近似恒定不变时突然激增。断层滑移失稳前声发射数较少或恒定不变与微震监测中的"缺震"现象较为吻合,即微震事件数在断层滑移失稳前或冲击地压发生前突然出现减少,发生后激增的现象。因此,断层滑动面应力和声发射事件数的激增变化特征可作为断层滑移失稳的前兆信息。
The relationship between complex geological structure and the occurrence of coal burst in coal mine is a major concern in coal mining.It is of theoretical significance and important engineering guidance to study the mechanism and precursory information of instability fault slip and coal burst for the safe and efficient production of coal mines.The stress evolution is focused on the fault plane by the methods of physical and numerical simulation to study the precursory information of instability fault slip during the coal mining.Based on the engineering background of the 21221 coal mining face at Yima mining area,Henan Province,China,a physical model with F_(16) thrust fault structure is constructed under the horizontal loading.The dynamical evolution characteristics of the shear stress on the fault sliding plane under mining disturbance are analyzed according to the stress sensors installed on the fault plane.The acoustic emission method is employed to monitor the acoustic emission events distributed on the fault plane.In addition,a numerical coal seam mining model with F_(16) thrust fault structure is also established to study the rock fracture development and strain energy release characteristics in the fault influenced zone.According the physical and numerical results,the precursory information of instability fault slip is summarized by investigating the stress distribution,acoustic emission monitoring and strain energy release on the fault plane.It is revealed that three stages in terms of shear stress evolution and acoustic emission events can be presented in the physical and numerical simulation,including horizontal pressure application stage,mining stage and fault slip stage.It can be seen that the acoustic emission events sharply increase since the strain energy continually accumulates on the fault plane during the horizontal pressure application stage.In the coal seam mining stage,due to the fault is frequently disturbed by coal seam mining,the normal stress and shear stress on the fault plane present different variation.In the earlier mining stage,the normal stress is greater than shear stress.As the advancement of coal mining,the change of normal stress and shear stress are exactly opposite.The normal stress gradually decreases while the shear stress gradually increases.In addition,the shear stress on the fault plane experiences the process of gradual decrease and sharp increase when the mining face is approaching the fault structure.In the fault slip stage,strain energy is accumulated again on the fault plane before the occurrence of fault slip but the acoustic emission events disappear.However,due to the continually energy release,the acoustic emission events sharply increase when the fault slip and the collapse of rock strata occur.The relative less or constant number of acoustic emission events before the instability fault slip is consistent with the micro-seismic events in micro-seismic monitoring in which the number of micro-seismic events decrease before the occurrence of coal burst and then suddenly increase after the coal burst.Therefore,the sharp increase of shear stress and acoustic emission events during the constant process can be regarded as the precursory information of instability fault slip.
The relationship between complex geological structure and the occurrence of coal burst in coal mine is a major concern in coal mining.It is of theoretical significance and important engineering guidance to study the mechanism and precursory information of instability fault slip and coal burst for the safe and efficient production of coal mines.The stress evolution is focused on the fault plane by the methods of physical and numerical simulation to study the precursory information of instability fault slip during the coal mining.Based on the engineering background of the 21221 coal mining face at Yima mining area,Henan Province,China,a physical model with F_(16) thrust fault structure is constructed under the horizontal loading.The dynamical evolution characteristics of the shear stress on the fault sliding plane under mining disturbance are analyzed according to the stress sensors installed on the fault plane.The acoustic emission method is employed to monitor the acoustic emission events distributed on the fault plane.In addition,a numerical coal seam mining model with F_(16) thrust fault structure is also established to study the rock fracture development and strain energy release characteristics in the fault influenced zone.According the physical and numerical results,the precursory information of instability fault slip is summarized by investigating the stress distribution,acoustic emission monitoring and strain energy release on the fault plane.It is revealed that three stages in terms of shear stress evolution and acoustic emission events can be presented in the physical and numerical simulation,including horizontal pressure application stage,mining stage and fault slip stage.It can be seen that the acoustic emission events sharply increase since the strain energy continually accumulates on the fault plane during the horizontal pressure application stage.In the coal seam mining stage,due to the fault is frequently disturbed by coal seam mining,the normal stress and shear stress on the fault plane present different variation.In the earlier mining stage,the normal stress is greater than shear stress.As the advancement of coal mining,the change of normal stress and shear stress are exactly opposite.The normal stress gradually decreases while the shear stress gradually increases.In addition,the shear stress on the fault plane experiences the process of gradual decrease and sharp increase when the mining face is approaching the fault structure.In the fault slip stage,strain energy is accumulated again on the fault plane before the occurrence of fault slip but the acoustic emission events disappear.However,due to the continually energy release,the acoustic emission events sharply increase when the fault slip and the collapse of rock strata occur.The relative less or constant number of acoustic emission events before the instability fault slip is consistent with the micro-seismic events in micro-seismic monitoring in which the number of micro-seismic events decrease before the occurrence of coal burst and then suddenly increase after the coal burst.Therefore,the sharp increase of shear stress and acoustic emission events during the constant process can be regarded as the precursory information of instability fault slip.
引文
[1] 姜耀东,潘一山,姜福兴,等.我国煤炭开采中的冲击地压机理和防治[J].煤炭学报,2014,39(2):205-213.JIANG Yaodong,PAN Yishan,JIANG Fuxing,et al.State of the art review on mechanism and prevention of coal bumps in China[J].Journal of China Coal Society,2014,39(2):205-213.
[2] 袁亮,姜耀东,何学秋,等.煤矿典型动力灾害风险精准判识及监控预警关键技术研究进展[J].煤炭学报,2018,43(2):306-318.YUAN Liang,JIANG Yaodong,HE Xueqiu,et al.Research progress of precise risk accurate identification and monitoring early warning on typical dynamic disasters in coal mine[J].Journal of China Coal Society,2018,43(2):306-318.
[3] 袁亮.煤及共伴生资源精准开采科学问题与对策[J].煤炭学报,2019,44(1):1-9.YUAN Liang.Scientific problem and countermeasure for precision mining of coal and associated resources[J].Journal of China Coal Society,2019,44(1):1-9.
[4] 姜耀东,赵毅鑫.我国煤矿冲击地压的研究现状:机制、预警与控制[J].岩石力学与工程学报,2015,34(11):2188-2204.JIANG Yaodong,ZHAO Yixin.State of the art:Investigation on mechanism,forecast and control of coal bumps in China[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(11):2188-2204.
[5] DENG Shuxin,LI Jie,JIANG Haiming,et al.Experimental and theoretical study of the fault slip events of rock masses around underground tunnels induced by external disturbances[J].Engineering Geology,2018,233:191-199.
[6] WANG Hongwei,JIANG Yaodong,XUE Sheng,et al.Influence of fault slip on mining-induced pressure and optimization of roadway support design in fault-influenced zone[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):660-671.
[7] 宋义敏,马少鹏,杨小彬,等.断层黏滑动态变形过程的实验研究[J].地球物理学报,2012,55(1):171-179.SONG Yimin,MA Shaopeng,YANG Xiaobin,et al.Experimental study on the displacement evolution of fault in stick-slip process[J].Chinese Journal of Geophysics,2012,55(1):171-179.
[8] 吕进国,姜耀东,李守国,等.巨厚坚硬顶板条件下断层诱冲特征及机制[J].煤炭学报,2014,39(10):1961-1969.Lü Jinguo,JIANG Yaodong,LI Shouguo,et al.Characteristics and mechanism research of coal bumps induced by faults based on extra thick and hard roof[J].Journal of China Coal Society,2014,39(10):1961-1969.
[9] 李守国,吕进国,姜耀东,等.逆断层不同倾角对采场冲击地压的诱导分析[J].采矿与安全工程学报,2014,3(6):870-875.LI Shouguo,Lü Jinguo,JIANG Yaodong,et al.Coal bump inducing rule by dip angles of thrust fault[J].Journal of Mining & Safety Engineering,2014,3(6):870-875.
[10] 李志华,窦林名,陈国祥,等.采动影响下断层冲击矿压危险性研究[J].中国矿业大学学报,2010,39(4):490-495,545.LI Zhihua,DOU Linming,CHEN Guoxiang,et al.The risk of fault induced rock burst during mining[J].Journal of China University of Mining & Technology,2010,39(4):490-495,545.
[11] 李志华,窦林名,陆振裕,等.采动诱发断层滑移失稳的研究[J].采矿与安全工程学报,2010,27(4):499-504.LI Zhihua,DOU Linming,LU Zhenyu,et al.Study of the fault slide destabilization induced by coal mining[J].Journal of Mining and Safety Engineering,2010,27(4):499-504.
[12] 李志华,窦林名,曹安业,等.采动影响下断层滑移诱发煤岩冲击机理[J].煤炭学报,2011,36(1):68-73.LI Zhihua,DOU Linming,CAO Anye,et al.Mechanism of fault slip induced rock burst during mining[J].Journal of China Coal Society,2011,36(1):68-73.
[13] 姜耀东,王涛,陈涛,等.“两硬”条件正断层影响下的冲击地压发生规律研究[J].岩石力学与工程学报,2013,32(S2):3712-3718.JIANG Yaodong,WANG Tao,CHEN Tao,et al.Features of coal bumps influence by normel faults in coal mining with hard roof and hard coal[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(S2):3712-3718.
[14] 姜耀东,王涛,赵毅鑫,等.采动影响下断层活化规律的数值模拟研究[J].中国矿业大学学报,2013,42(1):1-5.JIANG Yaodong,WANG Tao,ZHAO Yixin,et al.Numerical simulation of fault activation pattern induced by coal extraction[J].Journal of China University of Mining & Technology,2013,42(1):1-5.
[15] 王学滨,潘一山,海龙.基于剪切应变梯度塑性理论的断层岩爆失稳判据[J].岩石力学与工程学报,2004,23(4):588-591.WANG Xuebin,PAN Yishan,HAI Long.Instability criterion of fault rockburst based on gradient-dependent plasticity[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(4):588-591.
[16] 王学滨,宋维源,黄梅,等.考虑水致弱化及应变梯度的断层岩爆分析[J].岩石力学与工程学报,2004,23(11):1815-1818.WANG Xuebin,SONG Weiyuan,HUANG Mei,et al.Analysis on fault rockburst considering effects of water weakening and strain gradient[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(11):1815-1818.
[17] 王学滨.基于能量原理的岩样单轴压缩剪切破坏失稳判据[J].工程力学,2007,24(1):153-156,161.WANG Xuebin.Unstable criterion of rock specimen subjected to shear failure in uniaxial compression based on energy principle[J].Engineering Mechanics,2007,24(1):153-156,161.
[18] 王来贵,潘一山,梁冰,等.矿井不连续面冲击地压发生过程分析[J].辽宁工程技术大学学报(自然科学版),1996,5(3):61-64.WANG Laigui,PAN Yishan,LIANG Bing,et al.Analysis of rockburst process for noncontinuous area in mines[J].China Mining Magazine,1996,5(3):61-64.
[19] 左建平,裴建良,刘建锋,等.煤岩体破裂过程中声发射行为及时空演化机制[J].岩石力学与工程学报,2011,30(8):1564-1570.ZUO Jianping,PEI Jianliang,LIU Jianfeng,et al.Investigation on acoustic emission behavior and its time-space evolution mechanism in failure process of coal-rock combined body[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(8):1564-1570.
[20] 赵扬锋,刘力强,潘一山,等.岩石变形破裂微震、电荷感应、自电位和声发射实验研究[J].岩石力学与工程学报,2017,36(1):107-122.ZHAO Yangfeng,LIU Liqiang,PAN Yishan,et al.Experiment study on microseismic,charge induction,self-potential and acoustic emission during fracture process of rocks[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(1):107-122.
[21] 赵善坤.采动影响下逆冲断层“活化”特征试验研究[J].采矿与安全工程学报,2016,33(2):354-360.ZHAO Shankun.Experiments on the characteristics of thrust fault activation influenced by mining operation[J].Journal of Mining and Safety Engineering,2016,33(2):354-360.
[2] 袁亮,姜耀东,何学秋,等.煤矿典型动力灾害风险精准判识及监控预警关键技术研究进展[J].煤炭学报,2018,43(2):306-318.YUAN Liang,JIANG Yaodong,HE Xueqiu,et al.Research progress of precise risk accurate identification and monitoring early warning on typical dynamic disasters in coal mine[J].Journal of China Coal Society,2018,43(2):306-318.
[3] 袁亮.煤及共伴生资源精准开采科学问题与对策[J].煤炭学报,2019,44(1):1-9.YUAN Liang.Scientific problem and countermeasure for precision mining of coal and associated resources[J].Journal of China Coal Society,2019,44(1):1-9.
[4] 姜耀东,赵毅鑫.我国煤矿冲击地压的研究现状:机制、预警与控制[J].岩石力学与工程学报,2015,34(11):2188-2204.JIANG Yaodong,ZHAO Yixin.State of the art:Investigation on mechanism,forecast and control of coal bumps in China[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(11):2188-2204.
[5] DENG Shuxin,LI Jie,JIANG Haiming,et al.Experimental and theoretical study of the fault slip events of rock masses around underground tunnels induced by external disturbances[J].Engineering Geology,2018,233:191-199.
[6] WANG Hongwei,JIANG Yaodong,XUE Sheng,et al.Influence of fault slip on mining-induced pressure and optimization of roadway support design in fault-influenced zone[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):660-671.
[7] 宋义敏,马少鹏,杨小彬,等.断层黏滑动态变形过程的实验研究[J].地球物理学报,2012,55(1):171-179.SONG Yimin,MA Shaopeng,YANG Xiaobin,et al.Experimental study on the displacement evolution of fault in stick-slip process[J].Chinese Journal of Geophysics,2012,55(1):171-179.
[8] 吕进国,姜耀东,李守国,等.巨厚坚硬顶板条件下断层诱冲特征及机制[J].煤炭学报,2014,39(10):1961-1969.Lü Jinguo,JIANG Yaodong,LI Shouguo,et al.Characteristics and mechanism research of coal bumps induced by faults based on extra thick and hard roof[J].Journal of China Coal Society,2014,39(10):1961-1969.
[9] 李守国,吕进国,姜耀东,等.逆断层不同倾角对采场冲击地压的诱导分析[J].采矿与安全工程学报,2014,3(6):870-875.LI Shouguo,Lü Jinguo,JIANG Yaodong,et al.Coal bump inducing rule by dip angles of thrust fault[J].Journal of Mining & Safety Engineering,2014,3(6):870-875.
[10] 李志华,窦林名,陈国祥,等.采动影响下断层冲击矿压危险性研究[J].中国矿业大学学报,2010,39(4):490-495,545.LI Zhihua,DOU Linming,CHEN Guoxiang,et al.The risk of fault induced rock burst during mining[J].Journal of China University of Mining & Technology,2010,39(4):490-495,545.
[11] 李志华,窦林名,陆振裕,等.采动诱发断层滑移失稳的研究[J].采矿与安全工程学报,2010,27(4):499-504.LI Zhihua,DOU Linming,LU Zhenyu,et al.Study of the fault slide destabilization induced by coal mining[J].Journal of Mining and Safety Engineering,2010,27(4):499-504.
[12] 李志华,窦林名,曹安业,等.采动影响下断层滑移诱发煤岩冲击机理[J].煤炭学报,2011,36(1):68-73.LI Zhihua,DOU Linming,CAO Anye,et al.Mechanism of fault slip induced rock burst during mining[J].Journal of China Coal Society,2011,36(1):68-73.
[13] 姜耀东,王涛,陈涛,等.“两硬”条件正断层影响下的冲击地压发生规律研究[J].岩石力学与工程学报,2013,32(S2):3712-3718.JIANG Yaodong,WANG Tao,CHEN Tao,et al.Features of coal bumps influence by normel faults in coal mining with hard roof and hard coal[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(S2):3712-3718.
[14] 姜耀东,王涛,赵毅鑫,等.采动影响下断层活化规律的数值模拟研究[J].中国矿业大学学报,2013,42(1):1-5.JIANG Yaodong,WANG Tao,ZHAO Yixin,et al.Numerical simulation of fault activation pattern induced by coal extraction[J].Journal of China University of Mining & Technology,2013,42(1):1-5.
[15] 王学滨,潘一山,海龙.基于剪切应变梯度塑性理论的断层岩爆失稳判据[J].岩石力学与工程学报,2004,23(4):588-591.WANG Xuebin,PAN Yishan,HAI Long.Instability criterion of fault rockburst based on gradient-dependent plasticity[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(4):588-591.
[16] 王学滨,宋维源,黄梅,等.考虑水致弱化及应变梯度的断层岩爆分析[J].岩石力学与工程学报,2004,23(11):1815-1818.WANG Xuebin,SONG Weiyuan,HUANG Mei,et al.Analysis on fault rockburst considering effects of water weakening and strain gradient[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(11):1815-1818.
[17] 王学滨.基于能量原理的岩样单轴压缩剪切破坏失稳判据[J].工程力学,2007,24(1):153-156,161.WANG Xuebin.Unstable criterion of rock specimen subjected to shear failure in uniaxial compression based on energy principle[J].Engineering Mechanics,2007,24(1):153-156,161.
[18] 王来贵,潘一山,梁冰,等.矿井不连续面冲击地压发生过程分析[J].辽宁工程技术大学学报(自然科学版),1996,5(3):61-64.WANG Laigui,PAN Yishan,LIANG Bing,et al.Analysis of rockburst process for noncontinuous area in mines[J].China Mining Magazine,1996,5(3):61-64.
[19] 左建平,裴建良,刘建锋,等.煤岩体破裂过程中声发射行为及时空演化机制[J].岩石力学与工程学报,2011,30(8):1564-1570.ZUO Jianping,PEI Jianliang,LIU Jianfeng,et al.Investigation on acoustic emission behavior and its time-space evolution mechanism in failure process of coal-rock combined body[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(8):1564-1570.
[20] 赵扬锋,刘力强,潘一山,等.岩石变形破裂微震、电荷感应、自电位和声发射实验研究[J].岩石力学与工程学报,2017,36(1):107-122.ZHAO Yangfeng,LIU Liqiang,PAN Yishan,et al.Experiment study on microseismic,charge induction,self-potential and acoustic emission during fracture process of rocks[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(1):107-122.
[21] 赵善坤.采动影响下逆冲断层“活化”特征试验研究[J].采矿与安全工程学报,2016,33(2):354-360.ZHAO Shankun.Experiments on the characteristics of thrust fault activation influenced by mining operation[J].Journal of Mining and Safety Engineering,2016,33(2):354-360.
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