煤矿地下水库煤柱坝体宽度设计
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摘要
地下水库储水技术已成为西部矿区实现煤炭高效开采与水资源保护并重的重要途径之一,而煤柱坝体的稳定性是地下水库设计中极其重要的部分,对地下水库稳定性起决定性作用。煤柱坝体既要保证煤炭安全开采,也要保障地下水库安全运行。地下水库煤柱坝体的稳定不仅与埋深、采动应力、地质构造等工程地质条件有关,也与水作用下的弱化作用密切相关。为研究煤矿地下水库煤柱坝体在水作用下强度弱化规律,选取西部矿区麻地梁矿5煤为研究对象,开展煤样无损浸水试验和不同含水率及反复浸水条件下单轴压缩试验。研究得到:不同含水率的煤样在0～20 h内,含水率快速增长; 20 h之后,含水率增长变缓,在20～70 h,含水率慢速增长;在70～140 h,煤样含水率增长接近稳定;煤样含水率随着浸水时间的增加而增加,但增幅逐渐减少,最终趋于稳定;随着含水率(浸水次数)的增多,煤样单轴抗压强度逐渐降低,峰值应变逐渐增大,弹性模量逐渐降低。相较于干燥煤样,初次饱水煤样、浸水3次煤样单轴抗压强度分别降低了27.1%,50.0%,弹性模量分别降低34.6%,58.5%。结合实验室试验结果,运用弹塑性力学理论探讨了煤柱坝体在不同含水率下破坏区、塑性区宽度,开展了考虑覆岩压力、水压力以及水的弱化作用下煤柱坝体宽度设计研究,并结合麻地梁矿的工程地质条件,对其地下水库坝体的宽度进行了设计。同时,进一步分析了煤柱坝体宽度的影响因素,得到含水率、埋深、煤层采厚均对煤柱坝体宽度有很大影响。
Groundwater reservoir technology is a vital way to achieve both efficient mining and water conservation in western coalfields in China.The stability of coal pillar dam is an emphasis of reservoir design,which plays an important role in the stability of groundwater reservoirs.Coal pillar dam should ensure the safety of coal mining,as well as the safe operation of groundwater reservoirs.The stability of coal pillar dam is closely related to water weakening and engineering geological conditions,such as buried depth,mining stress,geological structure and so on.In order to study the strength weakening law of coal pillar dam of groundwater reservoirs under water,this paper took Madiliang mine No.5 in western mining area as the research object,carried out a non-destructive water immersion test on coal sample and a uniaxial compression test on coal sample under various water content and repeated soaking.The results show that the water content of coal samples with various water content increased rapidly within 0-20 h; after 20 h,the grew rate slowed down; and in 20-70 h,the water content grew slowly; in 70-140 h,the growth of water content of coal sample was nearly stable.In conclusion,the water content of coal sample increases with the soaking time,but the increase rate gradually decreases,and finally tends to be flat.With the increase of water content( the number of times of soaking),the uniaxial compressive strength of coal sample decreases gradually,but the peak strain increases gradually,and the elastic modulus decreases gradually.Compared with the dry coal sample,the uniaxial compressive strength of the first water-saturation coal sample and the coal sample with the third soaking decreased by 27.1% and 50.0% respectively,and the elastic modulus decreased by 34.6% and 58.5% respectively.Combined with the above results and the elasticplastic mechanics theory,this paper discussed the damage zone and plastic zone width of coal pillar dam under various water content,carried out the research of coal pillar dam width considering overburden rock pressure,water pressure and water weakening,and designed the width of the groundwater reservoir combining with the engineering geological conditions of Madiliang mine.At the same time,the paper further analyzed the influencing factors of the width of coal pillar dam,concluding that the width of coal pillar dam is closely affected by water content,buried depth,and mining thickness.
Groundwater reservoir technology is a vital way to achieve both efficient mining and water conservation in western coalfields in China.The stability of coal pillar dam is an emphasis of reservoir design,which plays an important role in the stability of groundwater reservoirs.Coal pillar dam should ensure the safety of coal mining,as well as the safe operation of groundwater reservoirs.The stability of coal pillar dam is closely related to water weakening and engineering geological conditions,such as buried depth,mining stress,geological structure and so on.In order to study the strength weakening law of coal pillar dam of groundwater reservoirs under water,this paper took Madiliang mine No.5 in western mining area as the research object,carried out a non-destructive water immersion test on coal sample and a uniaxial compression test on coal sample under various water content and repeated soaking.The results show that the water content of coal samples with various water content increased rapidly within 0-20 h; after 20 h,the grew rate slowed down; and in 20-70 h,the water content grew slowly; in 70-140 h,the growth of water content of coal sample was nearly stable.In conclusion,the water content of coal sample increases with the soaking time,but the increase rate gradually decreases,and finally tends to be flat.With the increase of water content( the number of times of soaking),the uniaxial compressive strength of coal sample decreases gradually,but the peak strain increases gradually,and the elastic modulus decreases gradually.Compared with the dry coal sample,the uniaxial compressive strength of the first water-saturation coal sample and the coal sample with the third soaking decreased by 27.1% and 50.0% respectively,and the elastic modulus decreased by 34.6% and 58.5% respectively.Combined with the above results and the elasticplastic mechanics theory,this paper discussed the damage zone and plastic zone width of coal pillar dam under various water content,carried out the research of coal pillar dam width considering overburden rock pressure,water pressure and water weakening,and designed the width of the groundwater reservoir combining with the engineering geological conditions of Madiliang mine.At the same time,the paper further analyzed the influencing factors of the width of coal pillar dam,concluding that the width of coal pillar dam is closely affected by water content,buried depth,and mining thickness.
引文
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[12]陈阳.煤矿地下水库挡水坝体防渗型式与渗控效果研究[D].北京:清华大学,2015.CHEN Yang.Research on the seepage prevention and seepage control effect of coal mine underground reservoir water retaining dam[D].Beijing:Tsinghua University,2015.
[13]张国恩.煤矿地下水库人工挡水坝安全性分析[J].中国煤炭,2014,(S1):78-81.ZHANG Guoen.Safety analysis of artificial blocking dam in underground coal mine reservoir[J].China Coal,2014,(S1):78-81.
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[15]陈田.水对煤样力学性质与破坏形式的影响[D].徐州:中国矿业大学,2017.CHEN Tian.Effects of water on mechanical properties of and failure modes in coal[D].Xuzhou:China University of Mining and Technology,2017.
[16]GAO Wei.Study on the width of the non-elastic zone in inclined coal pillar for strip mining[J].International Journal of Rock Mechanics and Mining Sciences,2014,12(78):304-310.
[17]王学滨.软化模量对岩样全部变形特征的影响[J].岩土工程学报,2006,28(5):600-605.WANG Xuebin.Effect of softening modulus on entire deformational characteristics of rock specimen[J].Chinese Journal of Geotechnical Engineering,2006,28(5):600-605.
[18]马念杰,侯朝炯.采准巷道矿压理论及应用[M].北京:煤炭工业出版社,1995.
[19]KANONO C M.Analysis of coal material by slurry nebulization ICP-OES[D].Tshwane:Tshwane University of Technology,2008.
[20]FLECK N A,MULLER G M,ASHBY M F,et al.Strain gradient plasticity:Theory and experiment[J].Acta Metallurgica et Materialia,1994,42(2):475-487.
[21]袁前进.综放面煤壁片帮的理论分析和防治[J].煤炭科技,2009,1(2):44-47.YUAN Qianjin.Prevention and theoretic analysis of rib fall in fully mechanized caving face[J].Coal Science&Technology Magazine,2009,1(2):44-47.
[22]蒋金泉,宋振骐.回采工作面底板活动及其对突水影响的研究[J].山东矿业学院学报,1987(4):1-11.JIANG Jinquan,SONG Zhenqi.Study on working face floor activities and its impact on water-inrush[J].Journal of Shandong Institute of Mining,1987(4):1-11.
[23]王学滨,潘一山,于海军.考虑塑性应变率梯度的单轴压缩岩样轴向响应[J].岩土力学,2004,24(6):943-946.WANG Xuebin,PAN Yishan,YU Haijun.Axial response of rock specimen considering strain rate gradient effect in uniaxial compression[J].Rock and Soil Mechanics,2004,24(6):943-946.
[24]LI Huigui,LI Huamin.Mechanical properties and acoustic emission characteristics of thick hard roof sandstone in Shendong coal field[J].International Journal of Coal Science&Technology,2017,4(2):147-158.
[25]周健.俯仰斜开采工作面煤壁失稳破坏机理及控制[D].徐州:中国矿业大学,2015.ZHOU Jian.Instability and failure mechanism of coal wall at coalface with up-dip or down-dip mining and its control[D].Xuzhou:China University of Mining and Technology,2015.
[26]陈苏社.神东矿区井下采空区水库水资源循环利用关键技术研究[D].西安:西安科技大学,2016.CHEN Sushe.Research on the key technology of water resources recycling utilization in the underground goaf reservoir in Shendong mining area[D].Xi’an:Xi’an University of Science and Technology,2016.
[2]王双明,黄庆享,范立明,等.生态脆弱区煤炭开发与生态水文保护[M].北京:科学出版社,2010.
[3]黄庆享.浅埋煤层保水开采岩层控制研究[J].煤炭学报,2017,42(1):50-55.HUANG Qingxiang.Research on roof control of water conservation mining in shallow seam[J].Journal of China Coal Society,2017,42(1):50-55.
[4]范立民,马雄德,冀瑞君.西部生态脆弱矿区保水采煤研究与实践进展[J].煤炭学报,2015,40(8):1711-1717.FAN Limin,MA Xiongde,JI Ruijun.Progress in engineering practice of water-preserved coal mining in western eco-environment frangible area[J].Journal of China Coal Society,2015,40(8):1711-1717.
[5]鞠金峰,许家林,朱卫兵.西部缺水矿区地下水库保水的库容研究[J].煤炭学报,2017,42(2):381-387.JU Jinfeng,XU Jialin,ZHU Weibing.Storage capacity of underground reservoir in the Chinese western water-short coalfield[J].Journal of China Coal Society,2017,42(2):381-387.
[6]顾大钊.煤矿地下水库理论框架和技术体系[J].煤炭学报,2015,40(2):239-246.GU Dazhao.Theory framework and technological system of coal mine underground reservoir[J].Journal of China Coal Society,2015,40(2):239-246.
[7]曹志国,何瑞敏,王兴峰.地下水受煤炭开采的影响及其储存利用技术[J].煤炭科学技术,2014,42(12):113-116.CAO Zhiguo,HE Ruimin,WANG Xingfeng.Coal mining affected to underground water and underground water storage and utilization technology[J].Coal Science and Technology,2014,42(12):113-116.
[8]谢和平,王金华.中国煤炭科学产能[M].北京:煤炭工业出版社,2014.
[9]姚强岭,陈田,李学华,等.宁东侏罗系煤层顶板粗粒含水砂岩特性研究[J].煤炭学报,2017,42(1):183-188.YAO Qiangling,CHEN Tian,LI Xuehua,et al.Experimental study on coarsely water-bearing sandstone in roof of Jurassic coal seam[J].Journal of China Coal Society,2017,42(1):183-188.
[10]YAO Q,LI X,ZHOU J,et al.Experimental study of strength characteristics of coal specimens after water intrusion[J].Arabian Journal of Geosciences,2015,8(9):6779-6789.
[11]YAO Q,CHEN T,JU M,et al.Effects of water intrusion on mechanical properties of and crack propagation in coal[J].Rock Mechanics&Rock Engineering,2016,49(12):1-11.
[12]陈阳.煤矿地下水库挡水坝体防渗型式与渗控效果研究[D].北京:清华大学,2015.CHEN Yang.Research on the seepage prevention and seepage control effect of coal mine underground reservoir water retaining dam[D].Beijing:Tsinghua University,2015.
[13]张国恩.煤矿地下水库人工挡水坝安全性分析[J].中国煤炭,2014,(S1):78-81.ZHANG Guoen.Safety analysis of artificial blocking dam in underground coal mine reservoir[J].China Coal,2014,(S1):78-81.
[14]顾大钊,颜永国,张勇,等.煤矿地下水库煤柱动力响应与稳定性分析[J].煤炭学报,2016,41(7):1589-1597.GU Dazhao,YAN Yongguo,ZHANG Yong,et al.Experimental study and numerical simulation for dynamic response of coal pillars in coal mine underground reservoir[J].Journal of China Coal Society,2016,41(7):1589-1597.
[15]陈田.水对煤样力学性质与破坏形式的影响[D].徐州:中国矿业大学,2017.CHEN Tian.Effects of water on mechanical properties of and failure modes in coal[D].Xuzhou:China University of Mining and Technology,2017.
[16]GAO Wei.Study on the width of the non-elastic zone in inclined coal pillar for strip mining[J].International Journal of Rock Mechanics and Mining Sciences,2014,12(78):304-310.
[17]王学滨.软化模量对岩样全部变形特征的影响[J].岩土工程学报,2006,28(5):600-605.WANG Xuebin.Effect of softening modulus on entire deformational characteristics of rock specimen[J].Chinese Journal of Geotechnical Engineering,2006,28(5):600-605.
[18]马念杰,侯朝炯.采准巷道矿压理论及应用[M].北京:煤炭工业出版社,1995.
[19]KANONO C M.Analysis of coal material by slurry nebulization ICP-OES[D].Tshwane:Tshwane University of Technology,2008.
[20]FLECK N A,MULLER G M,ASHBY M F,et al.Strain gradient plasticity:Theory and experiment[J].Acta Metallurgica et Materialia,1994,42(2):475-487.
[21]袁前进.综放面煤壁片帮的理论分析和防治[J].煤炭科技,2009,1(2):44-47.YUAN Qianjin.Prevention and theoretic analysis of rib fall in fully mechanized caving face[J].Coal Science&Technology Magazine,2009,1(2):44-47.
[22]蒋金泉,宋振骐.回采工作面底板活动及其对突水影响的研究[J].山东矿业学院学报,1987(4):1-11.JIANG Jinquan,SONG Zhenqi.Study on working face floor activities and its impact on water-inrush[J].Journal of Shandong Institute of Mining,1987(4):1-11.
[23]王学滨,潘一山,于海军.考虑塑性应变率梯度的单轴压缩岩样轴向响应[J].岩土力学,2004,24(6):943-946.WANG Xuebin,PAN Yishan,YU Haijun.Axial response of rock specimen considering strain rate gradient effect in uniaxial compression[J].Rock and Soil Mechanics,2004,24(6):943-946.
[24]LI Huigui,LI Huamin.Mechanical properties and acoustic emission characteristics of thick hard roof sandstone in Shendong coal field[J].International Journal of Coal Science&Technology,2017,4(2):147-158.
[25]周健.俯仰斜开采工作面煤壁失稳破坏机理及控制[D].徐州:中国矿业大学,2015.ZHOU Jian.Instability and failure mechanism of coal wall at coalface with up-dip or down-dip mining and its control[D].Xuzhou:China University of Mining and Technology,2015.
[26]陈苏社.神东矿区井下采空区水库水资源循环利用关键技术研究[D].西安:西安科技大学,2016.CHEN Sushe.Research on the key technology of water resources recycling utilization in the underground goaf reservoir in Shendong mining area[D].Xi’an:Xi’an University of Science and Technology,2016.