特厚煤层卸压综放开采技术原理的实验研究
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摘要
我国西部地区发现存有大量20 m以上特厚煤层,大部分无法实现露天开采,国内外均没有成熟的理论与技术可以借鉴,为了实现20 m以上特厚煤层的安全高效开采,创造性地提出了特厚煤层卸压综放开采技术。采用60∶1的大比例相似模拟试验方法,研究20 m以上特厚煤层卸压综放开采顶煤垮落破碎的块体分布特征、顶煤位移场分布特征、支架阻力及其对顶煤垮落破碎的影响等。结果表明:当卸压工作面推进75 cm时,500 cm~3以内的顶煤块体较密集,块体比例约为94%,块体数量约为860个;当卸压工作面推进135 cm时,体积为500 cm~3以内的顶煤块体所占累计比例约为96%,块体数量约为1 700个,与卸压工作面推进75 cm时相比,块体比例增加了2%,块体数量增加了840个;当综放工作面推进17 cm时,累计体积达到500 cm~3时几乎包含全部顶煤块体,块体比例约为99.9%,块体数量约为4 810个,与卸压工作面推进135 cm时相比,块体比例增加了3.9%,块体数量增加了3 110个,二次破碎效果显著,能保证顶煤的顺利放出。卸压开采阶段上位顶煤位移>中位顶煤位移>下位顶煤位移。二次综放阶段下位顶煤位移最大,垮落破碎程度最好。由于支架的支撑作用,下位顶煤中产生多条明显的竖直裂隙,受支架影响的顶煤厚度约为10 cm,支架的反复支撑作用明显促进了顶煤的破碎效果。
A large number of extra-thick coal seams with a thickness of more than 20 m have been found in western China.Most of them cannot be mined by using open-pit mining.No mature theories and technologies can be referenced in the world.The fully mechanized caving mining with pressure relief for extra-thick coal seams was proposed for achieving a safe and efficient mining of extra-thick coal seams with a thickness of over 20 m.The large-scale of 60∶1 physical analogue test was used to study the distribution characteristics of the top coal caving and broken blocks,and the distribution characteristics of top coal displacement field.In addition,the test studied the support resistance and its effect on the top coal braking in the fully mechanized caving mining with pressure relief for extra-thick coal seams with a thickness of over 20 m.The results show that the number of top-coal blocks is denser within 500 cm~3,the block ratio is about 94% and the number of blocks is about 860 when the pressure relief working surface is extracted to 75 cm.The cumulative proportion of top-coal blocks is about 96% within 500 cm~3 and the number of blocks is about 1 700 when the pressure relief working surface is extracted to 135 cm.The proportion of the top-coal blocks increased by 2% and the number of blocks increased by 840 when compared with that of pressure relief working face at 75 cm.It contains almost all the top-coal blocks when the cumulative volume reaches 500 cm~3,the block ratio is about 99.9% and the number of blocks is about 4 810 when the top-coal working face is extracted to 17 cm.The top-coal blocks within 500 cm~3 is the most densest,the proportion of the blocks increased by 3.9% and the number of blocks increased by 3 110 when compared with that at 135 cm.The effect of secondary crushing is remarkable,which can ensure the smooth release of the top coal.In the stage of pressure relief mining,the displacement of upper top-coal is larger than that of the median top-coal and the displacement of the lower top-coal is the smallest.In the secondary fully mechanized top-coal caving mining stage,the lower top-coal displacement is the largest,and the effect of the top-coal collapse and fracture is the best.Many obvious vertical cracks were generated in the lower top-coal for the supporting effect of the support,and the thickness of the top-coal which affected by the support is approximately 10 cm.The repeated supporting effect of the support significantly promoted the broken effect of the top-coal.
A large number of extra-thick coal seams with a thickness of more than 20 m have been found in western China.Most of them cannot be mined by using open-pit mining.No mature theories and technologies can be referenced in the world.The fully mechanized caving mining with pressure relief for extra-thick coal seams was proposed for achieving a safe and efficient mining of extra-thick coal seams with a thickness of over 20 m.The large-scale of 60∶1 physical analogue test was used to study the distribution characteristics of the top coal caving and broken blocks,and the distribution characteristics of top coal displacement field.In addition,the test studied the support resistance and its effect on the top coal braking in the fully mechanized caving mining with pressure relief for extra-thick coal seams with a thickness of over 20 m.The results show that the number of top-coal blocks is denser within 500 cm~3,the block ratio is about 94% and the number of blocks is about 860 when the pressure relief working surface is extracted to 75 cm.The cumulative proportion of top-coal blocks is about 96% within 500 cm~3 and the number of blocks is about 1 700 when the pressure relief working surface is extracted to 135 cm.The proportion of the top-coal blocks increased by 2% and the number of blocks increased by 840 when compared with that of pressure relief working face at 75 cm.It contains almost all the top-coal blocks when the cumulative volume reaches 500 cm~3,the block ratio is about 99.9% and the number of blocks is about 4 810 when the top-coal working face is extracted to 17 cm.The top-coal blocks within 500 cm~3 is the most densest,the proportion of the blocks increased by 3.9% and the number of blocks increased by 3 110 when compared with that at 135 cm.The effect of secondary crushing is remarkable,which can ensure the smooth release of the top coal.In the stage of pressure relief mining,the displacement of upper top-coal is larger than that of the median top-coal and the displacement of the lower top-coal is the smallest.In the secondary fully mechanized top-coal caving mining stage,the lower top-coal displacement is the largest,and the effect of the top-coal collapse and fracture is the best.Many obvious vertical cracks were generated in the lower top-coal for the supporting effect of the support,and the thickness of the top-coal which affected by the support is approximately 10 cm.The repeated supporting effect of the support significantly promoted the broken effect of the top-coal.
引文
[1]王家臣.厚煤层开采理论与技术[M].北京:冶金工业出版社,2009:47-51.
[2]王家臣.我国放顶煤开采的工程实践与理论进展[J].煤炭学报,2018,43(1):43-51.WANG Jiachen.Engineering practice and theoretical progress of top-coal caving mining technology in China[J].Journal of China Coal Society,2018,43(1):43-51.
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[4]MAHDI Shabanimashcool,CHARLIE C Li.Numerical modelling of longwall mining and stability analysis of the gates in a coal mine[J].International Journal of Rock Mechanics and Mining Sciences,2012,51:24-34.
[5]HABIB Alehossein,BRETT A Poulsen.Stress analysis of longwall top-coal caving[J].International Journal of Rock Mechanics and Mining Sciences,2010,47:30-41.
[6]WANG Jiachen.The technical progress and problems to be solved of thick coal seam mining in China[A].Proceedings of 30th International Conference on Ground Control in Mining[C].Morgantown,2011.
[7]WANG Jinhua.Development and prospect on fully mechanized topcoal caving in Chinese coal mines[J].International Journal of Coal Science and Technology,2014,1(3):253-260.
[8]WANG Jiachen,YANG Shengli,LI Yang,et al.Caving mechanisms of loose top-coal in longwall top-coal caving mining method[J].International Journal of Rock Mechanics and Mining Sciences,2014,71:160-170.
[9]王家臣,富强.低位综放开采顶煤放出的散体介质流理论与应用[J].煤炭学报,2002,27(4):337-341.WANG Jiachen,FU Qiang.Low top-coal caving off the loose medium flow theory and application[J].Journal of China Coal Society,2002,27(4):337-341.
[10]王家臣,杨建立,刘颢颢,等.顶煤放出散体介质流理论的现场观测研究[J].煤炭学报,2010,35(3):353-356.WANG Jiachen,YANG Jianli,LIU Haohao,et al.The pratical observation research on loose medium flow field theory on topcoal caving[J].Journal of China Coal Society,2010,35(3):353-356.
[11]王家臣,李志刚,陈亚军,等.综放开采顶煤放出散体介质流理论的试验研究[J].煤炭学报,2004,29(3):260-263.WANG Jiachen,LI Zhigang,CHEN Yajun,et al.The experimental study of loose medium flow field on the longwall top-coal caving[J].Journal of China Coal Society,2004,29(3):260-263.
[12]王家臣,张锦旺.综放开采顶煤放出规律的BBR研究[J].煤炭学报,2015,40(3):487-493.WANG Jiachen,ZHANG Jinwang.BBR study of top-coal drawing law in longwall top-coal caving mining[J].Journal of China Coal Society 2015,40(3):487-493.
[13]王家臣,魏立科,张锦旺等.综放开采顶煤放出规律三维数值模拟[J].煤炭学报,2013,38(11):1905-1911.WANG Jiachen,WEI Like,ZHANG Jinwang,et al.3-D numerical simulation on the top-coal movement law under caving mining technique[J].Journal of China Coal Society,2013,38(11):1905-1911.
[14]刘长友,黄炳香.大采高综放工作面煤矸流场规律及放煤工艺参数确定[A].综放开采30周年科技论文集[C].北京:煤炭工业出版社,2012:379-385.LIU Changyou,HUANG Bingxiang.Determination of coal enthalpy flow field and coal mining process parameters in large mining height fully mechanized caving face[A].The 30th anniversary of fully mechanized caving mining technology papers[C].Beijing:Coal Industry Press,2012:379-385.
[15]吴健,张勇.综放采场支架-围岩关系的新概念[J].煤炭学报,2001,26(4):350-355.WU Jian,ZHANG Yong.The new concept of relationship between support and surrounding-rock in longwall top-coal caving faces[J].Journal of China Coal Society,2001,26(4):350-355.
[16]钱鸣高,缪协兴,何富连等.采场支架与围岩耦合作用机理研究[J].煤炭学报,1996,21(1):40-44.QIAN Minggao,MIAO Xiexing,HE Fulian,et al.Mechanism of coupling effect between supports in the working and the rocks[J].Journal of China Coal Society,1996,21(1):40-44.
[17]闫少宏,吴健.放顶煤开采顶煤运移实测与损伤特性分析[J].岩石力学与工程学报,1996,15(2):155-162.YAN Shaohong,WU Jian.Analysis of top-coal movement and damage characteristics in top-coal caving[J].Chinese Journal of Rock Mechanics and Engineering,1996,15(2):155-162.
[18]王家臣,王兆会.综放开采顶煤在加卸载复合作用下的破坏机理[J].同煤科技,2017,(3):1-8.WANG Jiachen,WANG Zhaohui.Failure mechanism of topcoal caving under the combined effect of loading and unloading[J].Science and Technology of Datong Mining Administration,2017,(3):1-8.
[19]王兆会.综放开采顶煤破坏机理与冒放性判别方法研究[D].北京:中国矿业大学(北京),2017.WANG Zhaohui.Failure mechanism and cavability evaluation of the top-coal in longwall top-coal caving mining[D].Beijing:China University of Mining&Technology(Beijing),2017.
[2]王家臣.我国放顶煤开采的工程实践与理论进展[J].煤炭学报,2018,43(1):43-51.WANG Jiachen.Engineering practice and theoretical progress of top-coal caving mining technology in China[J].Journal of China Coal Society,2018,43(1):43-51.
[3]VAKILI A,HEBBLEWHITE B.A new cavability assessment criterion for Longwall top-coal Caving[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(8):1317-1329.
[4]MAHDI Shabanimashcool,CHARLIE C Li.Numerical modelling of longwall mining and stability analysis of the gates in a coal mine[J].International Journal of Rock Mechanics and Mining Sciences,2012,51:24-34.
[5]HABIB Alehossein,BRETT A Poulsen.Stress analysis of longwall top-coal caving[J].International Journal of Rock Mechanics and Mining Sciences,2010,47:30-41.
[6]WANG Jiachen.The technical progress and problems to be solved of thick coal seam mining in China[A].Proceedings of 30th International Conference on Ground Control in Mining[C].Morgantown,2011.
[7]WANG Jinhua.Development and prospect on fully mechanized topcoal caving in Chinese coal mines[J].International Journal of Coal Science and Technology,2014,1(3):253-260.
[8]WANG Jiachen,YANG Shengli,LI Yang,et al.Caving mechanisms of loose top-coal in longwall top-coal caving mining method[J].International Journal of Rock Mechanics and Mining Sciences,2014,71:160-170.
[9]王家臣,富强.低位综放开采顶煤放出的散体介质流理论与应用[J].煤炭学报,2002,27(4):337-341.WANG Jiachen,FU Qiang.Low top-coal caving off the loose medium flow theory and application[J].Journal of China Coal Society,2002,27(4):337-341.
[10]王家臣,杨建立,刘颢颢,等.顶煤放出散体介质流理论的现场观测研究[J].煤炭学报,2010,35(3):353-356.WANG Jiachen,YANG Jianli,LIU Haohao,et al.The pratical observation research on loose medium flow field theory on topcoal caving[J].Journal of China Coal Society,2010,35(3):353-356.
[11]王家臣,李志刚,陈亚军,等.综放开采顶煤放出散体介质流理论的试验研究[J].煤炭学报,2004,29(3):260-263.WANG Jiachen,LI Zhigang,CHEN Yajun,et al.The experimental study of loose medium flow field on the longwall top-coal caving[J].Journal of China Coal Society,2004,29(3):260-263.
[12]王家臣,张锦旺.综放开采顶煤放出规律的BBR研究[J].煤炭学报,2015,40(3):487-493.WANG Jiachen,ZHANG Jinwang.BBR study of top-coal drawing law in longwall top-coal caving mining[J].Journal of China Coal Society 2015,40(3):487-493.
[13]王家臣,魏立科,张锦旺等.综放开采顶煤放出规律三维数值模拟[J].煤炭学报,2013,38(11):1905-1911.WANG Jiachen,WEI Like,ZHANG Jinwang,et al.3-D numerical simulation on the top-coal movement law under caving mining technique[J].Journal of China Coal Society,2013,38(11):1905-1911.
[14]刘长友,黄炳香.大采高综放工作面煤矸流场规律及放煤工艺参数确定[A].综放开采30周年科技论文集[C].北京:煤炭工业出版社,2012:379-385.LIU Changyou,HUANG Bingxiang.Determination of coal enthalpy flow field and coal mining process parameters in large mining height fully mechanized caving face[A].The 30th anniversary of fully mechanized caving mining technology papers[C].Beijing:Coal Industry Press,2012:379-385.
[15]吴健,张勇.综放采场支架-围岩关系的新概念[J].煤炭学报,2001,26(4):350-355.WU Jian,ZHANG Yong.The new concept of relationship between support and surrounding-rock in longwall top-coal caving faces[J].Journal of China Coal Society,2001,26(4):350-355.
[16]钱鸣高,缪协兴,何富连等.采场支架与围岩耦合作用机理研究[J].煤炭学报,1996,21(1):40-44.QIAN Minggao,MIAO Xiexing,HE Fulian,et al.Mechanism of coupling effect between supports in the working and the rocks[J].Journal of China Coal Society,1996,21(1):40-44.
[17]闫少宏,吴健.放顶煤开采顶煤运移实测与损伤特性分析[J].岩石力学与工程学报,1996,15(2):155-162.YAN Shaohong,WU Jian.Analysis of top-coal movement and damage characteristics in top-coal caving[J].Chinese Journal of Rock Mechanics and Engineering,1996,15(2):155-162.
[18]王家臣,王兆会.综放开采顶煤在加卸载复合作用下的破坏机理[J].同煤科技,2017,(3):1-8.WANG Jiachen,WANG Zhaohui.Failure mechanism of topcoal caving under the combined effect of loading and unloading[J].Science and Technology of Datong Mining Administration,2017,(3):1-8.
[19]王兆会.综放开采顶煤破坏机理与冒放性判别方法研究[D].北京:中国矿业大学(北京),2017.WANG Zhaohui.Failure mechanism and cavability evaluation of the top-coal in longwall top-coal caving mining[D].Beijing:China University of Mining&Technology(Beijing),2017.