孤岛充填工作面初采致冲力学机理探讨
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摘要
孤岛充填工作面由于要控制采空区顶板下沉而导致工作面煤体支承压力分布变得复杂,造成冲击危险性评估方法不同于常规工作面,为了提供充填回收孤岛煤柱采场围岩稳定性分析的理论依据,以山东某矿孤岛充填工作面为背景,通过对孤岛煤柱覆岩结构及演化特征进行研究,建立了孤岛充填开采条件下"充填体-煤柱-顶板"力学模型,得到了充填工作面超前支承压力估算方法,提出了孤岛充填工作面煤体冲击失稳的判据。研究结果表明:(1)采空区充填效果决定了上覆岩层下沉运动的空间以及与两侧采空区覆岩发生水平联动的范围,是影响孤岛煤柱覆岩结构演化特征的关键因素;(2)受回采巷道切割及大直径钻孔卸压工程的影响,工作面煤体承载能力呈现明显的区域差异性,弹性承载区煤体是上覆岩层传递载荷的主要承载体,工作面开采边界条件和回采巷道布置方式是影响工作面煤体静态稳定性的主要控制因素;(3)充填材料受到采空区顶板下沉运动中压应力作用下发生压缩变形,当顶板和充填材料达到力学平衡时顶板下沉运动终止,充填材料固结体压缩变形量和弹性模量是影响工作面煤体动态稳定性的主要控制因素;(4)决定孤岛充填工作面冲击危险性的关键因素是工作面弹性承载区煤体静态支承压力和采空区顶板下沉量。针对这类冲击地压的致灾机理,通过煤层注水、高压水压裂及优化工作面布置以降低工作面弹性承载区煤体静态支承压力和提高采空区充填率、优化充填材料固结体压缩性能以减小采空区顶板下沉量等措施,可有效降低孤岛充填工作面的冲击危险性。该研究成果可为类似开采条件下冲击地压的防治提供参考。
To control the roof subsidence in gob,the longwall panel is generally backfilled after mining.The rock burst risk evaluation method of the island backfill longwall panel(IBLW) is different from that of the normal longwall panel due to the complex distribution of its abutment pressure.In order to provide a theoretical basis for the stability analysis of surrounding rock during the retrieval of IBLW,by establishing a "filling body-island pan-el-roof "model based onthe evolution of the overburden structure,the evaluation method of abutment pressure in front of the working face and the criterion for rock burst were obtained.Research results are as follows:(1) The subsidence of the overburden strata above IBLW and the horizontal associated movement of the overburden strata above the gobs on both sides were determined by the filling effect which was also a key factor of overburden structure evolution.(2) Influenced by roadway tunneling and the de-stressing of large-diameter boreholes,the obvious regional difference of bearing capability of IBLW was observed.The load transferred from the overburden strata was mainly born by the elastic area of IBLW.The stability of IBLW was affected by its boundary conditions and layout of the roadways.(3) The filling materials deformed due to the subsidence movement of the roof,which stopped when mechanical equilibrium was reached.The stability of IBLW was mainly controlled by the compres-sive deformation and elastic modulus of the filling material.(4) The rock burst risk of IBLW was dependent on the static abutment pressure in the elastic area and subsidence of the roof above the gob.To prevent this kind of rock burst,the static abutment pressure can be reduced by injecting water into the coal seam,hydrofracturing and op-timizing the layout of longwall panels.Also,the roof subsidence can be controlled by improving the filling rate of the gob,optimizing the consolidation and compressive properties.This research result provides a technical guidance for rock burst prediction and control.
To control the roof subsidence in gob,the longwall panel is generally backfilled after mining.The rock burst risk evaluation method of the island backfill longwall panel(IBLW) is different from that of the normal longwall panel due to the complex distribution of its abutment pressure.In order to provide a theoretical basis for the stability analysis of surrounding rock during the retrieval of IBLW,by establishing a "filling body-island pan-el-roof "model based onthe evolution of the overburden structure,the evaluation method of abutment pressure in front of the working face and the criterion for rock burst were obtained.Research results are as follows:(1) The subsidence of the overburden strata above IBLW and the horizontal associated movement of the overburden strata above the gobs on both sides were determined by the filling effect which was also a key factor of overburden structure evolution.(2) Influenced by roadway tunneling and the de-stressing of large-diameter boreholes,the obvious regional difference of bearing capability of IBLW was observed.The load transferred from the overburden strata was mainly born by the elastic area of IBLW.The stability of IBLW was affected by its boundary conditions and layout of the roadways.(3) The filling materials deformed due to the subsidence movement of the roof,which stopped when mechanical equilibrium was reached.The stability of IBLW was mainly controlled by the compres-sive deformation and elastic modulus of the filling material.(4) The rock burst risk of IBLW was dependent on the static abutment pressure in the elastic area and subsidence of the roof above the gob.To prevent this kind of rock burst,the static abutment pressure can be reduced by injecting water into the coal seam,hydrofracturing and op-timizing the layout of longwall panels.Also,the roof subsidence can be controlled by improving the filling rate of the gob,optimizing the consolidation and compressive properties.This research result provides a technical guidance for rock burst prediction and control.
引文
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[3]姜福兴,曲效成,倪兴华,等.鲍店煤矿硬岩断裂型矿震的预测[J].煤炭学报,2013,38(S2):319-324.JIANG Fuxing,QU Xiaocheng,NI Xinghua,et al. Case study on the mine earthquake caused by rock fracture in Baodian Coal Mine[J].Journal of China Coal Society,2013,38(S2):319-324.
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[5]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.
[6]窦林名,陆菜平,牟宗龙,等.冲击矿压的强度弱化减冲理论及其应用[J].煤炭学报,2005,30(6):1-6.DOU Linming,LU Caiping,MOU Zonglong,et al. Intensity weakening theory for rockburst and its lication[J]. Journal of China Coal Society,2005,30(6):1-6.
[7] DOU Linming,MU Zonglong,LI Zhenlei,et al. Research progress of monitoring,forecasting,and prevention of rockburst in underground coal mining in China[J]. International Journal of Coal Science&Technology,2014,1(3):278-288.
[8]潘俊锋,宁宇,毛德兵,等.煤矿开采冲击地压启动理论[J].岩石力学与工程学报,2012,31(3):586-596.PAN Junfeng,NING Yu,MAO Debing,et al. Theory of rockburst start-up during coal mining[J]. Chinese Journal of rock Mechanics and Engineering,2012,31(3):586-596.
[9]潘立友,魏辉,陈理强,等.工程缺陷防控冲击地压机理及应用[J].岩土工程学报,2017,39(1):56-61.PAN Liyou,WEI Hui,CHEN Liqiang,et al.Mechanism and application of using engineering defect to prevent and control rockburst[J].Chinese Journal of Geotechnical Engineering,2017,39(1):56-61.
[10]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,2016,38(12):2398-2408.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 and Engineering,2016,38(12):2398-2408.
[11]潘一山.煤矿冲击地压扰动响应失稳理论及应用[J].煤炭学报,2018,43(8):2091-2098.PAN Yishan. Disturbance response instability theory of rockburst in coal mine[J]. Journal of China Coal Society,2018,43(8):2091-2098.
[12]陈绍杰,郭惟嘉,周辉,等.条带煤柱膏体充填开采覆岩结构模型及运动规律[J].煤炭学报,2011,36(7):1081-1086.CHEN Shaojie,GUO Weijia,ZHOU Hui,et al. Structure model and movement law of overburden during strip pillar mining backfill with cream-body[J].Journal of China Coal Society,2011,36(7):1081-1086.
[13]冯宇,姜福兴,李京达.孤岛工作面围岩整体失稳冲击危险性评估方法[J].煤炭学报,2015,40(5):1001-1007.FENG Yu,JIANG Fuxing,LI Jingda. Evaluation method of rock burst hazard induced by overall instability of island coal face[J].Journal of China Coal Society,2015,40(5):1001-1007.
[14]朱广安,窦林名,丁自伟,等.孤岛工作面采前冲击危险性预评估研究[J].岩土工程学报,2018,40(5):819-827.ZHU Guang’an,DOU Linming,DING Ziwei,et al. Pre-evaluation for rock burst risks in island longwall panel before mining[J].Chinese Journal of Geotechnical Engineering,2018,40(5):819-827.
[15] JIANG Y D,WANG H W,XUE S,et al.Assessment and mitigation of coal bump risk during extraction of an island longwall panel[J].International Journal of Coal Geology,2012,95(2):20-33.
[16]李振雷,窦林名,王桂峰,等.坚硬顶板孤岛煤柱工作面冲击特征及机制分析[J].采矿与安全工程学报,2014,31(4):519-524.LI Zhenlei,DOU Linming,WANG Guifeng,et al. Rock burst characteristics and mechanism induced within an island pillar coalface with hard roof[J]. Journal of Mining&Safety Engineering,2014,31(4):519-524.
[17]冯光明.超高水充填材料及其充填开采技术研究与应用[D].徐州:中国矿业大学,2009.FENG Guangming.Research on the superhigh-water packing material and filling mining technology and their application[D].Xuzhou:China University of Mining&Technology,2009.
[18]侯玮,姜福兴,王存文,等.三面采空综放采场“C”型覆岩空间结构及其矿压控制[J].煤炭学报,2009,34(3):310-314.HOU Wei,JIANG Fuxing,WANG Cunwen,et al.Pressure control in sub-level long face surrounded by three sides mined areas of Cshaped strata spatial structure[J]. Journal of China Coal Society,2009,34(3):310-314.
[19]朱斯陶.特厚煤层开采冲击地压机理与防治研究[D].北京:北京科技大学,2017.ZHU Sitao. Mechanism and prevention of rockburst in extrathick coal seams mining[D]. Beijing:University of Science and Technology Beijing,2017.
[20]安百富,张吉雄,李猛,等.充填回收房式煤柱采场煤柱稳定性分析[J].采矿与安全工程学报,2016,33(2):238-243.AN Baifu,ZHANG Jixiong,LI Meng,et al. Stability of pillars in backfilling mining working face to recover room mining standing pillars[J].Journal of Mining&Safety Engineering,2016,33(12):238-243.
[21]龙驭球.弹性地基梁的计算[M].北京:人民教育出版社,1981:7-27.
[22]陈卫忠,吕森鹏,郭小红,等.基于能量原理的卸围压试验与岩爆判据研究[J].岩石力学与工程学报,2009,28(8):1530-1540.CHEN Weizhong,LSenpeng,GUO Xiaohong,et al. Research on unloading confining pressure tests and rock-burst criterion based on energy theory[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(8):1530-1540.
[23]姜福兴,成功,冯宇,等.两侧不规则采空区孤岛工作面煤体整体冲击失稳研究[J].岩石力学与工程学报,2015,34(S2):4164-4170.JIANG Fuxing,CHENG Gong,FENG Yu,et al. Research on coal overall instability of isolated working face with irregular gobs on both sides[J]. Chinese Journal of Rock Mechanics and Engineering,2015,34(S2):4164-4170.
[24]于正兴,姜福兴,桂兵,等.防治冲击地压的应力三向化理论研究及应用[J].煤炭科学技术,2011,39(7):1-4.YU Zhengxing,JIANG Fuxing,GUI Bing,et al. Study and application of stress three-dimensional theory to pre-vention and control of mine pressure bumping[J].Coal Science and Technology,2011,39(7):1-4.
[2]朱广安,窦林名,刘阳,等.深埋复杂不规则孤岛工作面冲击矿压机制研究[J].采矿与安全工程学报,2016,33(4):630-635.ZHU Guang’an,DOU Linming,LIU Yang,et al. Rock burst mechanism analysis on deep irregular island face[J]. Journal of Mining&Safety Engineering,2016,33(4):630-635.
[3]姜福兴,曲效成,倪兴华,等.鲍店煤矿硬岩断裂型矿震的预测[J].煤炭学报,2013,38(S2):319-324.JIANG Fuxing,QU Xiaocheng,NI Xinghua,et al. Case study on the mine earthquake caused by rock fracture in Baodian Coal Mine[J].Journal of China Coal Society,2013,38(S2):319-324.
[4]王宏伟,姜耀东,杨忠东,等.长壁孤岛工作面煤岩冲击危险性区域多参量预测[J].煤炭学报,2012,37(11):1790-1795.WANG Hongwei,JIANG Yaodong,YANG Zhongdong,et al. Multivariable assessment of coal bump risk during extraction of an island longwall panel[J]. Jounal of China Coal Society,2012,37(11):1790-1795.
[5]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.
[6]窦林名,陆菜平,牟宗龙,等.冲击矿压的强度弱化减冲理论及其应用[J].煤炭学报,2005,30(6):1-6.DOU Linming,LU Caiping,MOU Zonglong,et al. Intensity weakening theory for rockburst and its lication[J]. Journal of China Coal Society,2005,30(6):1-6.
[7] DOU Linming,MU Zonglong,LI Zhenlei,et al. Research progress of monitoring,forecasting,and prevention of rockburst in underground coal mining in China[J]. International Journal of Coal Science&Technology,2014,1(3):278-288.
[8]潘俊锋,宁宇,毛德兵,等.煤矿开采冲击地压启动理论[J].岩石力学与工程学报,2012,31(3):586-596.PAN Junfeng,NING Yu,MAO Debing,et al. Theory of rockburst start-up during coal mining[J]. Chinese Journal of rock Mechanics and Engineering,2012,31(3):586-596.
[9]潘立友,魏辉,陈理强,等.工程缺陷防控冲击地压机理及应用[J].岩土工程学报,2017,39(1):56-61.PAN Liyou,WEI Hui,CHEN Liqiang,et al.Mechanism and application of using engineering defect to prevent and control rockburst[J].Chinese Journal of Geotechnical Engineering,2017,39(1):56-61.
[10]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,2016,38(12):2398-2408.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 and Engineering,2016,38(12):2398-2408.
[11]潘一山.煤矿冲击地压扰动响应失稳理论及应用[J].煤炭学报,2018,43(8):2091-2098.PAN Yishan. Disturbance response instability theory of rockburst in coal mine[J]. Journal of China Coal Society,2018,43(8):2091-2098.
[12]陈绍杰,郭惟嘉,周辉,等.条带煤柱膏体充填开采覆岩结构模型及运动规律[J].煤炭学报,2011,36(7):1081-1086.CHEN Shaojie,GUO Weijia,ZHOU Hui,et al. Structure model and movement law of overburden during strip pillar mining backfill with cream-body[J].Journal of China Coal Society,2011,36(7):1081-1086.
[13]冯宇,姜福兴,李京达.孤岛工作面围岩整体失稳冲击危险性评估方法[J].煤炭学报,2015,40(5):1001-1007.FENG Yu,JIANG Fuxing,LI Jingda. Evaluation method of rock burst hazard induced by overall instability of island coal face[J].Journal of China Coal Society,2015,40(5):1001-1007.
[14]朱广安,窦林名,丁自伟,等.孤岛工作面采前冲击危险性预评估研究[J].岩土工程学报,2018,40(5):819-827.ZHU Guang’an,DOU Linming,DING Ziwei,et al. Pre-evaluation for rock burst risks in island longwall panel before mining[J].Chinese Journal of Geotechnical Engineering,2018,40(5):819-827.
[15] JIANG Y D,WANG H W,XUE S,et al.Assessment and mitigation of coal bump risk during extraction of an island longwall panel[J].International Journal of Coal Geology,2012,95(2):20-33.
[16]李振雷,窦林名,王桂峰,等.坚硬顶板孤岛煤柱工作面冲击特征及机制分析[J].采矿与安全工程学报,2014,31(4):519-524.LI Zhenlei,DOU Linming,WANG Guifeng,et al. Rock burst characteristics and mechanism induced within an island pillar coalface with hard roof[J]. Journal of Mining&Safety Engineering,2014,31(4):519-524.
[17]冯光明.超高水充填材料及其充填开采技术研究与应用[D].徐州:中国矿业大学,2009.FENG Guangming.Research on the superhigh-water packing material and filling mining technology and their application[D].Xuzhou:China University of Mining&Technology,2009.
[18]侯玮,姜福兴,王存文,等.三面采空综放采场“C”型覆岩空间结构及其矿压控制[J].煤炭学报,2009,34(3):310-314.HOU Wei,JIANG Fuxing,WANG Cunwen,et al.Pressure control in sub-level long face surrounded by three sides mined areas of Cshaped strata spatial structure[J]. Journal of China Coal Society,2009,34(3):310-314.
[19]朱斯陶.特厚煤层开采冲击地压机理与防治研究[D].北京:北京科技大学,2017.ZHU Sitao. Mechanism and prevention of rockburst in extrathick coal seams mining[D]. Beijing:University of Science and Technology Beijing,2017.
[20]安百富,张吉雄,李猛,等.充填回收房式煤柱采场煤柱稳定性分析[J].采矿与安全工程学报,2016,33(2):238-243.AN Baifu,ZHANG Jixiong,LI Meng,et al. Stability of pillars in backfilling mining working face to recover room mining standing pillars[J].Journal of Mining&Safety Engineering,2016,33(12):238-243.
[21]龙驭球.弹性地基梁的计算[M].北京:人民教育出版社,1981:7-27.
[22]陈卫忠,吕森鹏,郭小红,等.基于能量原理的卸围压试验与岩爆判据研究[J].岩石力学与工程学报,2009,28(8):1530-1540.CHEN Weizhong,LSenpeng,GUO Xiaohong,et al. Research on unloading confining pressure tests and rock-burst criterion based on energy theory[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(8):1530-1540.
[23]姜福兴,成功,冯宇,等.两侧不规则采空区孤岛工作面煤体整体冲击失稳研究[J].岩石力学与工程学报,2015,34(S2):4164-4170.JIANG Fuxing,CHENG Gong,FENG Yu,et al. Research on coal overall instability of isolated working face with irregular gobs on both sides[J]. Chinese Journal of Rock Mechanics and Engineering,2015,34(S2):4164-4170.
[24]于正兴,姜福兴,桂兵,等.防治冲击地压的应力三向化理论研究及应用[J].煤炭科学技术,2011,39(7):1-4.YU Zhengxing,JIANG Fuxing,GUI Bing,et al. Study and application of stress three-dimensional theory to pre-vention and control of mine pressure bumping[J].Coal Science and Technology,2011,39(7):1-4.