基于震波CT探测的宽煤柱冲击地压防控技术
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摘要
针对深井区段煤柱冲击地压易发、多发、难防治的难题,以某矿1301工作面80 m区段宽煤柱冲击地压为例,利用数值模拟及微震数据分析,研究了宽煤柱冲击地压致灾机制,采用震波CT原位探测技术评估了宽煤柱区域内冲击危险性,并提出针对性防治方案。结果表明:3号煤层具有弱冲击倾向性,顶板岩层具有强冲击倾向性,已具备发生冲击地压的内在条件,高自重应力、强构造应力提供了基础静载荷,采空区侧向支承压力提供了增量静载荷,当两者叠加导致垂直应力超过冲击临界支承压力时,为宽煤柱静载荷冲击地压的发生提供了力源条件;震波CT原位探测技术以穿透煤岩体的实际震动波射线进行波速反演,反映煤岩体静载荷分布特征及结构特性,建立了以波速异常系数CA和波速梯度系数CG为主要因子的冲击地压危险性评估模型;鉴于宽煤柱冲击区域采掘空间实际条件,设计布置近完全观测系统观测方式,采用震波CT原位探测技术反演评估得到宽煤柱测区内冲击危险指数C=0. 5～0. 7,表明冲击发生后,宽煤柱仍然存在静载荷集中区域,具有中等冲击危险,并且运输巷侧冲击危险指数较采空区侧高,表明煤柱应力由采空区侧向运输巷侧转移,局部区域煤体破碎易冒顶片帮;制定了基于静载荷疏导的多层次防冲技术:大直径钻孔预卸压转移巷帮集中应力,耗散弹性应变能,确定合理日进尺为2. 4 m,降低开采扰动,巷道全断面补强支护,提高围岩抗冲击能力;通过上述措施,现场监测宽煤柱煤体应力未发生突增,微震能量及频次变化平缓,1301工作面已安全回采宽煤柱区,防治效果显著。
To overcome the problems of easy occurrence,frequent occurrence and difficult prevention of coal pillar rock burst in deep mine,taking the rock burst in 1301 roadway with 80 m wide coal pillar as an example,based on numerical simulation and microseism data analysis,the mechanism of rock burst in wide coal pillar was studied.The seismic CT in-situ detection technology was used to evaluate the risk of rock burst,and the corresponding prevention and control scheme was put forward. The results show that the weak burst tendency of No. 3 coal seam and the strong burst tendency of roof rock stratum were the intrinsic condition of rock burst,the high gravity stress and strong tectonic stress were basic static loads,and the lateral abutment pressure of goaf was incremental static loads.When the vertical stress exceeded the critical abutment pressure,it provided the force source condition for the occurrence of static load type rock burst in wide coal pillar.By inversing the wave velocity from the actual seismic wave rays,the seismic CT in-situ detection technology can reflect the distribution and structural characteristics of the static load,and establish a risk assessment model of rock burst with the abnormal coefficient of wave velocity CAand the gradient coefficient of wave velocity CGas the main factors. In terms of the actual mining conditions in the impact area of wide coal pillar,a nearcomplete observation system was designed and arranged.The seismic CT detection showed that after the occurrence,the burst hazard indices were C = 0.5-0.7 and had moderate degree burst hazard,the burst hazard index of the side of transport channel was higher than that of goaf,which indicated that the stress of coal pillar had transferred from the side of goaf to the side of transport channel.The local fractured zone had high risk of roof caving or rib spalling accident.The multi-level prevention and control technologies based on static load transformation were formulated including a large-diameter borehole pre-relief technology was used to transfer concentrated stress and dissipate elastic strain energy of roadway side; the 2.4 m/d advancing speed of working face was determined to reduce mining disturbance; and the support reinforcement of full roadway section was designed to improve the anti-impact ability. Through the above measures,the monitoring stress did not occur sudden increase,and the microseism energy and frequency was gentle.In1301 working face,the wide coal pillar area had safely been recovered,and the control effect was obvious.
To overcome the problems of easy occurrence,frequent occurrence and difficult prevention of coal pillar rock burst in deep mine,taking the rock burst in 1301 roadway with 80 m wide coal pillar as an example,based on numerical simulation and microseism data analysis,the mechanism of rock burst in wide coal pillar was studied.The seismic CT in-situ detection technology was used to evaluate the risk of rock burst,and the corresponding prevention and control scheme was put forward. The results show that the weak burst tendency of No. 3 coal seam and the strong burst tendency of roof rock stratum were the intrinsic condition of rock burst,the high gravity stress and strong tectonic stress were basic static loads,and the lateral abutment pressure of goaf was incremental static loads.When the vertical stress exceeded the critical abutment pressure,it provided the force source condition for the occurrence of static load type rock burst in wide coal pillar.By inversing the wave velocity from the actual seismic wave rays,the seismic CT in-situ detection technology can reflect the distribution and structural characteristics of the static load,and establish a risk assessment model of rock burst with the abnormal coefficient of wave velocity CAand the gradient coefficient of wave velocity CGas the main factors. In terms of the actual mining conditions in the impact area of wide coal pillar,a nearcomplete observation system was designed and arranged.The seismic CT detection showed that after the occurrence,the burst hazard indices were C = 0.5-0.7 and had moderate degree burst hazard,the burst hazard index of the side of transport channel was higher than that of goaf,which indicated that the stress of coal pillar had transferred from the side of goaf to the side of transport channel.The local fractured zone had high risk of roof caving or rib spalling accident.The multi-level prevention and control technologies based on static load transformation were formulated including a large-diameter borehole pre-relief technology was used to transfer concentrated stress and dissipate elastic strain energy of roadway side; the 2.4 m/d advancing speed of working face was determined to reduce mining disturbance; and the support reinforcement of full roadway section was designed to improve the anti-impact ability. Through the above measures,the monitoring stress did not occur sudden increase,and the microseism energy and frequency was gentle.In1301 working face,the wide coal pillar area had safely been recovered,and the control effect was obvious.
引文
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[11]夏永学,潘俊锋,王元杰,等.基于高精度微震监测的煤岩破裂与应力分布特征研究[J].煤炭学报,2011,36(2):239-243.XIA Yongxue,PAN Junfeng,WANG Yuanjie,et al.Study of rule of surrounding rock failure and stress distribution based on high-precision microseismic monitoring[J]. Journal of China Coal Society,2011,36(2):239-243.
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[13]王书文,毛德兵,杜涛涛,等.基于地震CT技术的冲击地压危险性评价模型[J].煤炭学报,2012,37(S1):1-6.WANG Shuwen,MAO Debing,DU Taotao,et al. Rockburst hazard evaluation model based on seismic CT technology[J]. Journal of China Coal Society,2012,37(S1):1-6.
[14]刘金海,姜福兴,孙广京,等.强排煤粉防治冲击地压的机制与应用[J].岩石力学与工程学报,2014,33(4):747-754.LIU Jinhai,JIANG Fuxing,SUN Guangjing,et al.Mechanism of intensive venting pulverized coal to prevent coal burst and its application[J]. Chinese Journal of Rock Mechanics Engineering,2014,33(4):747-754.
[15]鞠文君.急倾斜特厚煤层水平分层开采巷道冲击地压成因与防治技术研究[D].北京:北京交通大学,2009.JU Wenjun.Study on reasons of rock burst in roadway and prevention technology of steeply inclined and extremely thick coal seam with horizontally slicing way[D].Beijing:Beijing Jiaotong University,2009.
[16]鞠文君.冲击矿压巷道锚杆支护原理分析[J].煤矿开采,2009,14(3):59-61.JU Wenjun. Analysis of supporting principles of anchored-bolt in roadway with burst danger[J]. Coal Mining Technolgy,2009,14(3):59-61.
[17]康红普,吴拥政,何杰,等.深部冲击地压巷道锚杆支护作用研究与实践[J].煤炭学报,2015,40(10):2225-2233.KANG Hongpu,WU Yongzheng,HE Jie,et al. Rock bolting performance and field practice in deep roadway with rock burst[J].Journal of China Coal Society,2015,40(10):2225-2233.
[18]潘俊锋,宁宇,杜涛涛,等.区域大范围防范冲击地压的理论与体系[J].煤炭学报,2012,37(11):1803-1809.PAN Junfeng,NING Yu,DU Taotao,et al. The theory and system for preventing rock burst in large-scale areas[J].Journal of China Coal Society,2012,37(11):1803-1809.
[2]翟明华,姜福兴,齐庆新,等.冲击地压分类防治体系与应用[J].煤炭学报,2017,42(12):3116-3124.ZHAI Minghua,JIANG Fuxing,QI Qingxin,et al.Research and practice of rock burst classified control system[J]. Journal of China Coal Society,2017,42(12):3116-3124.
[3]齐庆新,李晓璐,赵善坤.煤矿冲击地压应力控制理论与实践[J].煤炭科学技术,2013,41(6):1-5.QI Qingxin,LI Xiaolu,ZHAO Shankun. Theory and practices on stress control of mine pressure bumping[J].Coal Science and Technology,2013,41(6):1-5.
[4]姜福兴,刘懿,张益超,等.采场覆岩的“载荷三带”结构模型及其在防冲领域的应用[J].岩石力学与工程学报,2016,35(12):2398-2409.JIANG Fuxing,LIU Yi,ZHANG Yichao.et al.A three-zone structure loading model of overlying strata and its application on rockburst prevention[J].Chinese Journal of Rock Mechanics Engineering,2016,35(12):2398-2409.
[5]王书文,鞠文君,潘俊锋.临空留巷底板冲击地压启动区判定与分步防治技术[J].煤炭学报,2017,42(11):2799-2807.WANG Shuwen,JU Wenjun,PAN Junfeng. Determination on startup area for floor rockburst at retained entry and its stepwise control technology[J]. Journal of China Coal Society,2017,42(11):2799-2807.
[6]潘立友,陈理强,张若祥.深部两软煤层沿空巷道冲击地压成因与防治研究[J].岩土工程学报,2015,37(8):1484-1489.PAN Liyou,CHEN Liqiang,ZHANG Ruoxiang. Cause for rockburst and control of gob side entry in deep two soft coal seams[J].Chinese Journal of Geotechnical Engineering,2015,37(8):1484-1489.
[7]杨伟利,姜福兴,温经林,等.遗留煤柱诱发冲击地压机理及其防治技术研究[J].采矿与安全工程学报,2014,31(6):876-880.YANG Weili,JIANG Fuxing,WEN Jinglin,et al. Study on mechanisms of rock burst induced by a left coal pillar and prevention technology[J].Journal of Mining&Safety Engnineering,2014,31(6):876-880.
[8]成云海,马衍坤,胡兆锋,等.综放采场外错布置区段巷道减冲机理与关键技术[J].煤炭学报,2016,41(3):564-570.CHENG Yunhai,MA Yankun,HU Zhaofeng,et al. Mechanism and key technologies of preventing rock burst by outward staggered entries arrangement in full-mechanized caving face[J]. Journal of China Coal Society,2016,41(3):564-570.
[9]李学华,梁顺,姚强岭,等.冲击倾向性围岩沿空掘巷防冲控制原理及应用[J].采矿与安全工程学报,2012,29(6):751-756.LI Xuehua,LIANG Shun,YAO Qiangling,et al.Control principle and its application of rock burst in roadway driving along goaf with outburst-proneness surrounding rocks[J]. Journal of Mining&Safety Engnineering,2012,29(6):751-756.
[10]姜福兴,舒凑先,王存文.基于应力叠加回采工作面冲击危险性评价[J].岩石力学与工程学报,2015,34(12):2428-2435.JIANG Fuxing,SHU Couxian,WANG Cunwen.Impact risk appraisal of stope working faces based on stress superimpositionn[J].Chinese Journal of Rock Mechanics Engineering,2015,34(12):2428-2435.
[11]夏永学,潘俊锋,王元杰,等.基于高精度微震监测的煤岩破裂与应力分布特征研究[J].煤炭学报,2011,36(2):239-243.XIA Yongxue,PAN Junfeng,WANG Yuanjie,et al.Study of rule of surrounding rock failure and stress distribution based on high-precision microseismic monitoring[J]. Journal of China Coal Society,2011,36(2):239-243.
[12]潘俊锋,毛德兵.冲击地压启动理论与成套技术[M].徐州:中国矿业大学出版社,2016:18-38.
[13]王书文,毛德兵,杜涛涛,等.基于地震CT技术的冲击地压危险性评价模型[J].煤炭学报,2012,37(S1):1-6.WANG Shuwen,MAO Debing,DU Taotao,et al. Rockburst hazard evaluation model based on seismic CT technology[J]. Journal of China Coal Society,2012,37(S1):1-6.
[14]刘金海,姜福兴,孙广京,等.强排煤粉防治冲击地压的机制与应用[J].岩石力学与工程学报,2014,33(4):747-754.LIU Jinhai,JIANG Fuxing,SUN Guangjing,et al.Mechanism of intensive venting pulverized coal to prevent coal burst and its application[J]. Chinese Journal of Rock Mechanics Engineering,2014,33(4):747-754.
[15]鞠文君.急倾斜特厚煤层水平分层开采巷道冲击地压成因与防治技术研究[D].北京:北京交通大学,2009.JU Wenjun.Study on reasons of rock burst in roadway and prevention technology of steeply inclined and extremely thick coal seam with horizontally slicing way[D].Beijing:Beijing Jiaotong University,2009.
[16]鞠文君.冲击矿压巷道锚杆支护原理分析[J].煤矿开采,2009,14(3):59-61.JU Wenjun. Analysis of supporting principles of anchored-bolt in roadway with burst danger[J]. Coal Mining Technolgy,2009,14(3):59-61.
[17]康红普,吴拥政,何杰,等.深部冲击地压巷道锚杆支护作用研究与实践[J].煤炭学报,2015,40(10):2225-2233.KANG Hongpu,WU Yongzheng,HE Jie,et al. Rock bolting performance and field practice in deep roadway with rock burst[J].Journal of China Coal Society,2015,40(10):2225-2233.
[18]潘俊锋,宁宇,杜涛涛,等.区域大范围防范冲击地压的理论与体系[J].煤炭学报,2012,37(11):1803-1809.PAN Junfeng,NING Yu,DU Taotao,et al. The theory and system for preventing rock burst in large-scale areas[J].Journal of China Coal Society,2012,37(11):1803-1809.