综放开采顶煤与覆岩力链结构及演化光弹试验研究
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摘要
综放开采过程中顶煤和覆岩由连续向非连续和散体介质状态转变,描述矿压在断裂覆岩和碎裂顶煤中的形成、传递方式和作用机理是综放开采矿压理论研究的难点.基于光弹试验原理,借助散体介质双轴加载双向流动光弹试验装置,对综放开采过程中散体顶煤与非连续覆岩关键层中力链网络结构及演化特征进行研究.研究发现:地层载荷在煤岩体中构成了错综复杂的弱-强力链网络.综放开采打破了初始力链网络结构的平衡,顶煤与覆岩中形成梁-拱复合力链拱结构,覆岩荷载以强力链形式传递到工作面前方煤体.随着工作面推进和顶煤放出,覆岩梁-拱力链网络不断扩展和演化,形成更大规模的力链拱结构.关键层弯曲、断裂和失稳运动,使工作面前方的强力链拱脚出现回缩现象,力链分布密度和强度增加,导致工作面来压现象.地层内水平力作用使顶煤与覆岩内的梁-拱力链结构效应较更加明显,整体拱结构形态愈加完整,强力链网络结构更加紧致,关键层断裂失稳时力链拱对工作面煤层的作用力更加显著.
In top coal caving mining,the state of top coal and overburden strata changes from continuous media to discontinuous and loose aggregate media. It is difficult to theoretically describe the transition and action of mining induced pressure in discrete top coal and fractured overlaying strata. Based on the photoelastic experiment principle,the network structure and the evolution characteristics of force chains in discrete top coal and discontinuous overlaying key strata are investigated during fully mechanized top coal caving mining by employing photoelastic test equipment that allows biaxial loading and bilateral particle flowing. The study shows that overburden load in discontinuous strata displays a complicated network composed by weak and strong force chains. Top coal caving mining destroys the equilibrium of the initial force chain network structure,and a composed beam- arch force chain structure forms in top coal and overlaying strata,where the overburden load is transformed into the front coal seam in the form of strong force chains.With mining face advancing and top coal caving,the beam- arch force chain network in overlaying strata develops,and a larger force chain arch structure forms. Bending,breaking and instable movement of the key strata give rise to an inverse moving of the force chain arching foot and a compaction process of the strong force chain network. The distribution density and intensity of force chains evidently increase,resulting in strong pressure phenomena taking place in the mining face. Under the biaxial loading condition,the effect of thebeam- arch force chain structure becomes much evident in the earth. The entire structure of the force chain arch displays perfectly,the structure of the strong force chain network becomes denser,and due to breaking and instability of the key stratum,the pressure phenomenon of the force chain arch in front of the mining face and coal seam manifests much pronounced.
In top coal caving mining,the state of top coal and overburden strata changes from continuous media to discontinuous and loose aggregate media. It is difficult to theoretically describe the transition and action of mining induced pressure in discrete top coal and fractured overlaying strata. Based on the photoelastic experiment principle,the network structure and the evolution characteristics of force chains in discrete top coal and discontinuous overlaying key strata are investigated during fully mechanized top coal caving mining by employing photoelastic test equipment that allows biaxial loading and bilateral particle flowing. The study shows that overburden load in discontinuous strata displays a complicated network composed by weak and strong force chains. Top coal caving mining destroys the equilibrium of the initial force chain network structure,and a composed beam- arch force chain structure forms in top coal and overlaying strata,where the overburden load is transformed into the front coal seam in the form of strong force chains.With mining face advancing and top coal caving,the beam- arch force chain network in overlaying strata develops,and a larger force chain arch structure forms. Bending,breaking and instable movement of the key strata give rise to an inverse moving of the force chain arching foot and a compaction process of the strong force chain network. The distribution density and intensity of force chains evidently increase,resulting in strong pressure phenomena taking place in the mining face. Under the biaxial loading condition,the effect of thebeam- arch force chain structure becomes much evident in the earth. The entire structure of the force chain arch displays perfectly,the structure of the strong force chain network becomes denser,and due to breaking and instability of the key stratum,the pressure phenomenon of the force chain arch in front of the mining face and coal seam manifests much pronounced.
引文
[1]Qian M G,Shi P W.Mine Pressure and Strata Control.Xuzhou:China University of Mining and Technology Press,2010(钱鸣高,石平五.矿山压力与岩层控制.徐州:中国矿业大学出版社,2010)
[2]Song Z Q.Practical Mine Pressure Control.Xuzhou:China University of Mining and Technology Press,1988(宋振骐.实用矿山压力控制.徐州:中国矿业大学出版社,1988)
[3]Qian M G,Miao X X,Xu J L,et al.Key Stratus Theory of Strata Control.Xuzhou:China University of Mining and Technology Press,2003(钱鸣高,缪协兴,许家林,等.岩层控制的关键层理论.徐州:中国矿业大学出版社,2003)
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[7]Xie G X.Mechanical characteristics of fully mechanized top-coal caving face and surrounding rock stress shell.J China Coal Soc,2005,30(3):309(谢广祥.综放面及其围岩宏观应力壳力学特征研究.煤炭学报,2005,30(3):309)
[8]Jiang F X.Design of Roof Strata Control and Expert System.Xuzhou:China University of Mining and Technology Press,1995(姜福兴.采场顶板控制设计及其专家系统.徐州:中国矿业大学出版社,1995)
[9]Wang J A.Analysis of roof coal medium state in caving roof coal mining face.J Xi'an Min Inst,1991(4):9(王金安.放顶煤工作面顶煤介质状态分析.西安矿业学院学报,1991(4):9)
[10]Yan S H,Wu J.Analysis of top coal movement and damage characteristics in top-coal caving.Chin J Rock Mech Eng,1996,15(2):155(闫少宏,吴健.放顶煤开采顶煤运移实测与损伤特性分析.岩石力学与工程学报,1996,15(2):155)
[11]Yan S H.Study on the Laws of Top-coal and Roof Strata Movement in Fully Mechanized Top-coal Caving Mining[Dissertation].Beijing:China University of Mining and Technology,1995(闫少宏.放顶煤开采顶煤与顶板活动规律研究[学位论文].北京:中国矿业大学,1995)
[12]Jin Z M,Wei J P,Jin W X.Research on fracture evolution law of coal mass in fully mechanized face.J China Coal Soc,2000,25(Suppl):43.(靳钟铭,魏锦平,靳文学.综放工作面煤体裂隙演化规律研究.煤炭学报,2000,25(增刊):43.
[13]Feng G C,Yu Z X,Zhang Q H.Research into the roof coal failure mechanism of the fully mechanized caving method.J Fuxin Min Inst Nat Sci,1992,11(3):51(冯国才,于政喜,张清和.综采放顶煤开采顶煤破碎机理研究.阜新矿业学院学报(自然科学版),1992,11(3):51)
[14]Wang J A,Han X G,Ren P Z.The identification of the damage state evolution in top coal caving mining.J China Coal Soc,2016,41(Suppl 1):1(王金安,韩现刚,任鹏召.综放开采顶煤介质状态演化的特征识别.煤炭学报,2016,41(增刊1):1)
[15]Wang J C,Fu Q.The loose medium flow field theory and its application on the longwall top-coal caving.J China Coal Soc,2002,27(4):337(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.煤炭学报,2002,27(4):337)
[16]Wang J C,Wei L K,Zhang J W,et al.3-D numerical simulation on the top-coal movement law under caving mining technique.J China Coal Soc,2013,38(11):1905(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.煤炭学报,2013,38(11):1905)
[17]Sun Q C,Wang G Q.Review on granular flow dynamics and its discrete element method.Adv Mech,2008,38(1):87(孙其诚,王光谦.颗粒流动力学及其离散模型述评.力学进展,2008,38(1):87)
[18]Sun Q C,Cheng X H,Ji S Y,et al.Advances in micro-macro mechanics of granular soil materials.Adv Mech,2011,41(3):351(孙其诚,程晓辉,季顺迎,等.岩土类颗粒物质宏-细观力学研究进展.力学进展,2011,41(3):351)
[19]Wang J A,Pang W D,Liang C,et al.A Photoelastic Experimental Apparatus for Biaxial Loading and Bilateral Flowing of Particles:China Patent,CN204556449U.2015--08--12(王金安,庞伟东,梁超,等.一种双向颗粒流动光弹实验装置:中国专利,CN204556449U.2015-08--12)
[20]Pang W D.Photoelastic Experimental Study on Force Chain Network in Top-coal and Overlaying Strata under Fully Mechanized Top-coal Caving Mining[Dissertation].Beijing:University of Science and Technology Beijing,2015(庞伟东.综放开采顶煤与覆岩力链结构光弹实验[学位论文].北京:北京科技大学,2015)
[21]Wang J A,Liang C,Pang W D.Photoelastic experiment on force chain evolution of particle aggregates under biaxial loading and flowing conditions.Rock Soil Mech,2016,37(11):1(王金安,梁超,庞伟东.颗粒体双轴加载双向流动力链演化光弹试验研究.岩土力学,2016,37(11):1)
[2]Song Z Q.Practical Mine Pressure Control.Xuzhou:China University of Mining and Technology Press,1988(宋振骐.实用矿山压力控制.徐州:中国矿业大学出版社,1988)
[3]Qian M G,Miao X X,Xu J L,et al.Key Stratus Theory of Strata Control.Xuzhou:China University of Mining and Technology Press,2003(钱鸣高,缪协兴,许家林,等.岩层控制的关键层理论.徐州:中国矿业大学出版社,2003)
[4]Wu J.A review of the fully mechanized coal mining with sub-level caving in the past 15 years.China Coal,1999,25(1):9(吴健.我国综放开采技术15年回顾.中国煤炭,1999,25(1):9)
[5]Wu J,Yan S H.Basic concepts of determining of resistance of face support with fully mechanized mining and top coal caving.Min Induced Pressure Roof Strata Control,1995(3-4):69(吴健,闫少宏.确定综放面支架工作阻力的基本概念.矿山压力与顶板管理,1995(3--4):69)
[6]Shi P W,Gao Z N.The failure laws of surrounding rocks and over lying bed in the steep special thickness seam mining.J China Coal Soc,2003,28(1):13(石平五,高召宁.急斜特厚煤层开采围岩与覆盖层破坏规律.煤炭学报,2003,28(1):13)
[7]Xie G X.Mechanical characteristics of fully mechanized top-coal caving face and surrounding rock stress shell.J China Coal Soc,2005,30(3):309(谢广祥.综放面及其围岩宏观应力壳力学特征研究.煤炭学报,2005,30(3):309)
[8]Jiang F X.Design of Roof Strata Control and Expert System.Xuzhou:China University of Mining and Technology Press,1995(姜福兴.采场顶板控制设计及其专家系统.徐州:中国矿业大学出版社,1995)
[9]Wang J A.Analysis of roof coal medium state in caving roof coal mining face.J Xi'an Min Inst,1991(4):9(王金安.放顶煤工作面顶煤介质状态分析.西安矿业学院学报,1991(4):9)
[10]Yan S H,Wu J.Analysis of top coal movement and damage characteristics in top-coal caving.Chin J Rock Mech Eng,1996,15(2):155(闫少宏,吴健.放顶煤开采顶煤运移实测与损伤特性分析.岩石力学与工程学报,1996,15(2):155)
[11]Yan S H.Study on the Laws of Top-coal and Roof Strata Movement in Fully Mechanized Top-coal Caving Mining[Dissertation].Beijing:China University of Mining and Technology,1995(闫少宏.放顶煤开采顶煤与顶板活动规律研究[学位论文].北京:中国矿业大学,1995)
[12]Jin Z M,Wei J P,Jin W X.Research on fracture evolution law of coal mass in fully mechanized face.J China Coal Soc,2000,25(Suppl):43.(靳钟铭,魏锦平,靳文学.综放工作面煤体裂隙演化规律研究.煤炭学报,2000,25(增刊):43.
[13]Feng G C,Yu Z X,Zhang Q H.Research into the roof coal failure mechanism of the fully mechanized caving method.J Fuxin Min Inst Nat Sci,1992,11(3):51(冯国才,于政喜,张清和.综采放顶煤开采顶煤破碎机理研究.阜新矿业学院学报(自然科学版),1992,11(3):51)
[14]Wang J A,Han X G,Ren P Z.The identification of the damage state evolution in top coal caving mining.J China Coal Soc,2016,41(Suppl 1):1(王金安,韩现刚,任鹏召.综放开采顶煤介质状态演化的特征识别.煤炭学报,2016,41(增刊1):1)
[15]Wang J C,Fu Q.The loose medium flow field theory and its application on the longwall top-coal caving.J China Coal Soc,2002,27(4):337(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.煤炭学报,2002,27(4):337)
[16]Wang J C,Wei L K,Zhang J W,et al.3-D numerical simulation on the top-coal movement law under caving mining technique.J China Coal Soc,2013,38(11):1905(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.煤炭学报,2013,38(11):1905)
[17]Sun Q C,Wang G Q.Review on granular flow dynamics and its discrete element method.Adv Mech,2008,38(1):87(孙其诚,王光谦.颗粒流动力学及其离散模型述评.力学进展,2008,38(1):87)
[18]Sun Q C,Cheng X H,Ji S Y,et al.Advances in micro-macro mechanics of granular soil materials.Adv Mech,2011,41(3):351(孙其诚,程晓辉,季顺迎,等.岩土类颗粒物质宏-细观力学研究进展.力学进展,2011,41(3):351)
[19]Wang J A,Pang W D,Liang C,et al.A Photoelastic Experimental Apparatus for Biaxial Loading and Bilateral Flowing of Particles:China Patent,CN204556449U.2015--08--12(王金安,庞伟东,梁超,等.一种双向颗粒流动光弹实验装置:中国专利,CN204556449U.2015-08--12)
[20]Pang W D.Photoelastic Experimental Study on Force Chain Network in Top-coal and Overlaying Strata under Fully Mechanized Top-coal Caving Mining[Dissertation].Beijing:University of Science and Technology Beijing,2015(庞伟东.综放开采顶煤与覆岩力链结构光弹实验[学位论文].北京:北京科技大学,2015)
[21]Wang J A,Liang C,Pang W D.Photoelastic experiment on force chain evolution of particle aggregates under biaxial loading and flowing conditions.Rock Soil Mech,2016,37(11):1(王金安,梁超,庞伟东.颗粒体双轴加载双向流动力链演化光弹试验研究.岩土力学,2016,37(11):1)