大断面综放沿空巷道基本顶破断结构与围岩稳定性分析
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摘要
综放沿空巷道围岩稳定性与上覆基本顶破断运动及其形成的结构密切相关。以王家岭矿为工程背景,建立综放沿空巷道覆岩结构力学模型,推导基本顶破断位置表达式并确定沿空巷道上覆岩层破断结构形式;采用UDEC数值软件分析不同破断结构形式下综放沿空巷道围岩塑性区、应力和位移演化规律。研究表明:1)侧向基本顶的破断位置与基本顶厚度和力学性质、地基系数、破断块体间的相互作用力等因素有关,结合试验工作面地质生产条件确定基本顶于距煤壁约6.2m处破断。2)随着煤柱宽度由大到小,煤柱承载性能及对顶板支撑作用降低;加之巷道与基本顶破断线间距逐渐减小,巷道受基本顶回转运动影响愈发剧烈,致使沿空巷道顶板中心线两侧应力不均匀分布,进而诱发顶板和两帮不对称变形破坏现象,而且煤柱宽度越小,不对称矿压显现越强烈。3)窄煤柱沿空巷道围岩控制的关键在于对煤柱侧顶板和煤柱帮等变形破坏起始部位进行有效支护,限制变形破坏扩展。工程实践表明,35 d后巷道变形趋于稳定,顶板下沉量47 mm,煤柱帮变形量35 mm,实体煤帮变形量19 mm,巷道控制效果明显。
The surrounding rock stability of gob-side entry with fully-mechanized caving mining has a close relationship with the breakage movement and structure formation of the main roof. Taking typical entry of Wangjialing coal mine as engineering background, an elastic foundation beam model of main roof is established, which treated the immediate roof and coal seam as Winkler foundation in the model.The main roof breakage location expression and its influencing factors are deduced, and then, the main roof breakage structural features of experimental entry are determined. UDEC is used to analyze damage, stress and displacement evolution of gob-side entry's surrounding rock under different breakage structure conditions. Our research shows: 1) Lateral main roof breakage position is related to its thickness, mechanical properties, foundation coefficient, interaction between broken blocks and other factors.Combined with the geological production conditions of the test face, the basic top is broken about 6.2 m away from the coal wall. 2) With main roof breakage line gradually approaching the entry, the main roof rotary motion influence of surrounding rock is increased significantly and leads to the stress uneven distribution along the center line of the entry. Some mine pressure phenomena like asymmetric sink and squeeze dislocation deformation begin to appear. And the smaller the coal pillar width, the more obvious the phenomena. 3) With narrow pillar, the process of gob-side entry deformation and failure is divided into six stages, which is from pillar side carrying capacity deduced by rock compression, to key block B's subsidence increases, to key block A's subsidence increases(even broken), to stress asymmetric distribution of entry, to asymmetrical roof subsidence and horizontal deformation dislocation, to the phenomenon(slippage, dislocation, embedding, stepped sinking) begin to appear between the immediate roof and coal pillar. Engineering practice shows that the entry deformation is stabilized after 35 days.Roof subsidence is 47 mm, pillar side deformation is 35 mm, and solid coal side deformation is 19 mm.The control effect of entry surrounding rock is obvious.
The surrounding rock stability of gob-side entry with fully-mechanized caving mining has a close relationship with the breakage movement and structure formation of the main roof. Taking typical entry of Wangjialing coal mine as engineering background, an elastic foundation beam model of main roof is established, which treated the immediate roof and coal seam as Winkler foundation in the model.The main roof breakage location expression and its influencing factors are deduced, and then, the main roof breakage structural features of experimental entry are determined. UDEC is used to analyze damage, stress and displacement evolution of gob-side entry's surrounding rock under different breakage structure conditions. Our research shows: 1) Lateral main roof breakage position is related to its thickness, mechanical properties, foundation coefficient, interaction between broken blocks and other factors.Combined with the geological production conditions of the test face, the basic top is broken about 6.2 m away from the coal wall. 2) With main roof breakage line gradually approaching the entry, the main roof rotary motion influence of surrounding rock is increased significantly and leads to the stress uneven distribution along the center line of the entry. Some mine pressure phenomena like asymmetric sink and squeeze dislocation deformation begin to appear. And the smaller the coal pillar width, the more obvious the phenomena. 3) With narrow pillar, the process of gob-side entry deformation and failure is divided into six stages, which is from pillar side carrying capacity deduced by rock compression, to key block B's subsidence increases, to key block A's subsidence increases(even broken), to stress asymmetric distribution of entry, to asymmetrical roof subsidence and horizontal deformation dislocation, to the phenomenon(slippage, dislocation, embedding, stepped sinking) begin to appear between the immediate roof and coal pillar. Engineering practice shows that the entry deformation is stabilized after 35 days.Roof subsidence is 47 mm, pillar side deformation is 35 mm, and solid coal side deformation is 19 mm.The control effect of entry surrounding rock is obvious.
引文
[1]王金华.特厚煤层大采高综放开采关键技术[J].煤炭学报,2013,38(12):2089-2098.WANG Jinhua.Key technology for fully-mechanized top coal caving with large mining height in extra-thick coal seam[J].Journal of China Coal Society,2013,38(12):2089-2098.
[2]何富连,张广超.大断面采动剧烈影响煤巷变形破坏机制与控制技术[J].采矿与安全工程学报,2016,33(3):423-430.HE Fulian,ZHANG Guangchao.Deformation and failure mechanism and control technology of large section coal roadway subjected to severe mining dynamic load[J].Journal of Mining&Safety Engineering,2016,33(3):423-430.
[3]钱鸣高,缪协兴,何富连.采场“砌体梁”结构的关键块分析[J].煤炭学报,1994,19(6):557-563.QIAN Minggao,MIAO Xiexing,HE Fulian.Analysis of key block in the structure of voussoir beam in long wall mining[J].Journal of China Coal Society,1994,19(6):557-563.
[4]柏建彪,侯朝炯,黄汉富.沿空掘巷窄煤柱稳定性数值模拟研究[J].岩石力学与工程学报,2004,23(20):3475-3479.BAI Jianbiao,HOU Chaojiong,HUANG Hanfu.Numerical simulation study on stability of narrow coal pillar of roadway driving along goaf[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(20):3475-3479.
[5]侯朝炯,李学华.综放沿空掘巷围岩大、小结构的稳定性原理[J].煤炭学报,2001,26(1):1-7.HOU Chaojiong,LI Xuehua.Stability principle of big and small structures of rock surrounding roadway driven along goaf in fully mechanized top coal caving face[J].Journal of China Coal Society,2001,26(1):1-7.
[6]查文化,李雪,华心祝,等.基本顶断裂位置对窄煤柱护巷的影响及应用[J].煤炭学报,2014,39(2):332-338.ZHA Wenhua,LI Xue,HUA Xinzhu,et al.Impact and application on narrow coal pillar for roadway protecting from fracture position of upper roof[J].Journal of China Coal Society,2014,39(2):332-338.
[7]王红胜,张东升,李树刚,等.基于基本顶关键岩块B断裂线位置的窄煤柱合理宽度的确定[J].采矿与安全工程学报,2014,31(1):10-16.WANG Hongsheng,ZHANG Dongsheng,LI Shugang,et al.Rational width of narrow coal pillar based on the fracture line location of key rock B in main roof[J].Journal of Mining&Safety Engineering,2014,31(1):10-16.
[8]王德超,李术才,王琦,等.深部厚煤层综放沿空掘巷煤柱合理宽度试验研究[J].岩石力学与工程学报,2014,33(3):539-548.WANG Dechao,LI Shucai,WANG Qi,et al.Experimental study of reasonable coal pillar width in fully mechanized top coal caving face of thick coal seam[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(3):539-548.
[9]成云海,姜福兴,庞继禄.特厚煤层综放开采采空区侧向矿压特征及应用[J].煤炭学报,2012,37(7):1088-1093.CHENG Yunhai,JIANG Fuxing,PANG Jilu.Research on lateral strata pressure characteristic in goaf of top coal caving in extra thick coal seam and its application[J].Journal of China Coal Society,2012,37(7):1088-1093.
[10]张源,万志军,李付臣,等.不稳定覆岩下沿空掘巷围岩大变形机理[J].采矿与安全工程学报,2012,29(4):451-458.ZHANG Yuan,WAN Zhijun,LI Fuchen,et al.Large deformation mechanism of roadway driving along goaf under unstable overlying rock strata[J].Journal of Mining&Safety Engineering,2012,29(4):451-458.
[11]张广超,何富连.大断面强采动综放煤巷顶板非对称破坏机制与控制对策[J].岩石力学与工程学报,2016,35(4):806-818.ZHANG Guangchao,He Fulian.Asymmetric failure and control measures of large cross-section entry roof with strong mining disturbance and fully-mechanized caving mining[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(4):806-818.
[12]钱鸣高,石平五.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2003:45-46.
[13]蒋金泉,王普,武泉林,等.上覆高位岩浆岩下离层空间的演化规律及其预测[J].岩土工程学报,2015,37(10):1769-1779.JIANG Jinquan,WANG Pu,WU Quanlin,et al.Evolution laws and prediction of separated stratum space under overlying high-position magmatic rocks[J].Chinese Journal of Geotechnical Engineering,2015,37(10):1769-1779.
[14]张广超,何富连.大断面综放沿空巷道煤柱合理宽度与围岩控制[J].岩土力学,2016,37(6):1721-1728.ZHANG Guangchao,HE Fulian.Pillar width determination and surrounding rocks control of gob-side entry with large cross-section and fully-mechanized mining[J].Rock and Soil Mechanics,2016,37(6):1721-1728.
[2]何富连,张广超.大断面采动剧烈影响煤巷变形破坏机制与控制技术[J].采矿与安全工程学报,2016,33(3):423-430.HE Fulian,ZHANG Guangchao.Deformation and failure mechanism and control technology of large section coal roadway subjected to severe mining dynamic load[J].Journal of Mining&Safety Engineering,2016,33(3):423-430.
[3]钱鸣高,缪协兴,何富连.采场“砌体梁”结构的关键块分析[J].煤炭学报,1994,19(6):557-563.QIAN Minggao,MIAO Xiexing,HE Fulian.Analysis of key block in the structure of voussoir beam in long wall mining[J].Journal of China Coal Society,1994,19(6):557-563.
[4]柏建彪,侯朝炯,黄汉富.沿空掘巷窄煤柱稳定性数值模拟研究[J].岩石力学与工程学报,2004,23(20):3475-3479.BAI Jianbiao,HOU Chaojiong,HUANG Hanfu.Numerical simulation study on stability of narrow coal pillar of roadway driving along goaf[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(20):3475-3479.
[5]侯朝炯,李学华.综放沿空掘巷围岩大、小结构的稳定性原理[J].煤炭学报,2001,26(1):1-7.HOU Chaojiong,LI Xuehua.Stability principle of big and small structures of rock surrounding roadway driven along goaf in fully mechanized top coal caving face[J].Journal of China Coal Society,2001,26(1):1-7.
[6]查文化,李雪,华心祝,等.基本顶断裂位置对窄煤柱护巷的影响及应用[J].煤炭学报,2014,39(2):332-338.ZHA Wenhua,LI Xue,HUA Xinzhu,et al.Impact and application on narrow coal pillar for roadway protecting from fracture position of upper roof[J].Journal of China Coal Society,2014,39(2):332-338.
[7]王红胜,张东升,李树刚,等.基于基本顶关键岩块B断裂线位置的窄煤柱合理宽度的确定[J].采矿与安全工程学报,2014,31(1):10-16.WANG Hongsheng,ZHANG Dongsheng,LI Shugang,et al.Rational width of narrow coal pillar based on the fracture line location of key rock B in main roof[J].Journal of Mining&Safety Engineering,2014,31(1):10-16.
[8]王德超,李术才,王琦,等.深部厚煤层综放沿空掘巷煤柱合理宽度试验研究[J].岩石力学与工程学报,2014,33(3):539-548.WANG Dechao,LI Shucai,WANG Qi,et al.Experimental study of reasonable coal pillar width in fully mechanized top coal caving face of thick coal seam[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(3):539-548.
[9]成云海,姜福兴,庞继禄.特厚煤层综放开采采空区侧向矿压特征及应用[J].煤炭学报,2012,37(7):1088-1093.CHENG Yunhai,JIANG Fuxing,PANG Jilu.Research on lateral strata pressure characteristic in goaf of top coal caving in extra thick coal seam and its application[J].Journal of China Coal Society,2012,37(7):1088-1093.
[10]张源,万志军,李付臣,等.不稳定覆岩下沿空掘巷围岩大变形机理[J].采矿与安全工程学报,2012,29(4):451-458.ZHANG Yuan,WAN Zhijun,LI Fuchen,et al.Large deformation mechanism of roadway driving along goaf under unstable overlying rock strata[J].Journal of Mining&Safety Engineering,2012,29(4):451-458.
[11]张广超,何富连.大断面强采动综放煤巷顶板非对称破坏机制与控制对策[J].岩石力学与工程学报,2016,35(4):806-818.ZHANG Guangchao,He Fulian.Asymmetric failure and control measures of large cross-section entry roof with strong mining disturbance and fully-mechanized caving mining[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(4):806-818.
[12]钱鸣高,石平五.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2003:45-46.
[13]蒋金泉,王普,武泉林,等.上覆高位岩浆岩下离层空间的演化规律及其预测[J].岩土工程学报,2015,37(10):1769-1779.JIANG Jinquan,WANG Pu,WU Quanlin,et al.Evolution laws and prediction of separated stratum space under overlying high-position magmatic rocks[J].Chinese Journal of Geotechnical Engineering,2015,37(10):1769-1779.
[14]张广超,何富连.大断面综放沿空巷道煤柱合理宽度与围岩控制[J].岩土力学,2016,37(6):1721-1728.ZHANG Guangchao,HE Fulian.Pillar width determination and surrounding rocks control of gob-side entry with large cross-section and fully-mechanized mining[J].Rock and Soil Mechanics,2016,37(6):1721-1728.
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