组合煤岩体动态力学性能及瞬变磁场特征研究
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摘要
煤与瓦斯突出是顶板-煤体-底板综合力学作用的结果,单纯研究煤体或岩体力学特性难以充分揭示煤与瓦斯突出机理。为了揭示组合煤岩体的动态力学特性及瞬变磁场信号特征,采用霍普金森压杆实验系统研究了组合煤岩体的动态力学性能,分析了组合煤岩体动态破坏过程中的瞬变磁场信号特征。实验结果表明,组合煤岩体受到冲击破坏后,岩石破碎块度大,煤体破碎块度较小,强度低的煤体对组合试样具有很好的应力衰减和削波作用,应力波通过组合试样后,应力衰减为原来的1/5;组合煤岩体对应力波的衰减弱化效应主要取决于煤体的微观结构,煤体的微观结构使煤体受到冲击载荷后其塑性变形增强,弹性模量逐渐减小,与组合试样相比,单一试样表现出明显的脆性破坏特征;组合试样的平均应变率、最大应变率、断裂应力极限值和破坏应变与瞬变磁场信号幅值具有一定的相关性,随着组合试样冲击速度、平均应变率、最大应变率和断裂应力极限值的增大,组合试样所产生的磁场信号幅值也逐步增大,破坏应变与瞬变磁场信号幅值呈现出负相关关系,但两者相关性不强,离散性较大。
Coal and gas outburst is the comprehensive mechanics result of roof-coal body-floor.It is difficult to fully reveal mechanism of coal and gas outburst by simply studying mechanical characteristics of coal or rock.In order to reveal dynamic mechanical properties and transient magnetic field signal characteristics of composite coal and rock mass,the dynamic mechanical properties of composite coal and rock mass were studied by Hopkinson pressure bar experiment system,and the signal characteristics of transient magnetic field of composite coal and rock mass were analyzed during dynamic failure process.The experiment results show that after composite coal and rock is impacted,the rock fragmentation is large,the coal fragmentation is small,and the coal with low strength has good stress attenuation and wave clipping effect on the composite sample.The stress attenuation decreases to 1/5 of the original after the stress wave passes through the composite sample.The attenuation and weakening effect of the composite coal and rock mass on the stress wave mainly depends on the microstructure of the coal body,and the microstructure of the coal body makes the plastic deformation of coal body increase and elastic modulus decrease gradually after being subjected to impact load.Compared with the composite samples,the single sample shows obvious brittle failure characteristics.The average strain rate,maximum strain rate,fracture stress limit value and failure strain of the composite samples have certain correlation with the amplitude of transient magnetic signals.With increase of the impact speed,average strain rate,maximum strain rate,fracture stress limit value of the composite samples,the amplitude of transient magnetic signals generated by the composite sample increases gradually,and the magnitude of damage strain and the amplitude of transient magnetic signals show a negative correlation,but the correlation between them is not strong and the discrete type is large.
Coal and gas outburst is the comprehensive mechanics result of roof-coal body-floor.It is difficult to fully reveal mechanism of coal and gas outburst by simply studying mechanical characteristics of coal or rock.In order to reveal dynamic mechanical properties and transient magnetic field signal characteristics of composite coal and rock mass,the dynamic mechanical properties of composite coal and rock mass were studied by Hopkinson pressure bar experiment system,and the signal characteristics of transient magnetic field of composite coal and rock mass were analyzed during dynamic failure process.The experiment results show that after composite coal and rock is impacted,the rock fragmentation is large,the coal fragmentation is small,and the coal with low strength has good stress attenuation and wave clipping effect on the composite sample.The stress attenuation decreases to 1/5 of the original after the stress wave passes through the composite sample.The attenuation and weakening effect of the composite coal and rock mass on the stress wave mainly depends on the microstructure of the coal body,and the microstructure of the coal body makes the plastic deformation of coal body increase and elastic modulus decrease gradually after being subjected to impact load.Compared with the composite samples,the single sample shows obvious brittle failure characteristics.The average strain rate,maximum strain rate,fracture stress limit value and failure strain of the composite samples have certain correlation with the amplitude of transient magnetic signals.With increase of the impact speed,average strain rate,maximum strain rate,fracture stress limit value of the composite samples,the amplitude of transient magnetic signals generated by the composite sample increases gradually,and the magnitude of damage strain and the amplitude of transient magnetic signals show a negative correlation,but the correlation between them is not strong and the discrete type is large.
引文
[1]何满潮,谢和平,彭苏萍,等.深部开采岩体力学研究[J].岩石力学与工程学报,2005,24(16):2803-2813.HE Manchao,XIE Heping,PENG Suping,et al.Study on rock mechanics in deep mining engineering[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(16):2803-2813.
[2]李希勇,张修峰.典型深部重大冲击地压事故原因分析及防治对策[J].煤炭科学技术,2003,31(2):15-17.LI Xiyong,ZHANG Xiufeng.Accident cause analysis and prevention measures of typical deep mine heavy pressure bump[J].Coal Science and Technology,2003,31(2):15-17.
[3]李胜林,刘殿书,李祥龙,等.Φ75mm分离式霍普金森压杆试件长度效应的试验研究[J].中国矿业大学学报,2010,39(1):93-97.LI Shenglin,LIU Dianshu,LI Xianglong,et al.The effect of specimen length inΦ75mm split Hopkinson pressure bar experiment[J].Journal of China University of Mining &Technology,2010,39(1):93-97.
[4]黄理兴,陈奕柏.我国岩石动力学研究状况与发展[J].岩石力学与工程学报,2003,22(11):1881-1886.HUANG Lixing,CHEN Yibai.Rock dynamics in China:past,present and future[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(11):1881-1886.
[5]黄理兴.岩石动力学研究成就与趋势[J].岩土力学,2011,32(10):2889-2900.HUANG Lixing.Development and new achievements of rock dynamics in China[J].Rock and Soil Mechanics,2011,32(10):2889-2900.
[6]撒占友,何学秋,王恩元.煤与瓦斯突出危险性电磁辐射异常判识方法[J].煤炭学报,2008,33(12):1373-1376.SA Zhanyou,HE Xueqiu,WANG Enyuan.EMR anomaly identification method of coal and gas outburst fatalness[J].Journal of China Coal Society,2008,33(12):1373-1376.
[7]程擂,韩焱,王鉴,等.基于改进HHT的水中爆炸冲击波信号时频特性分析方法[J].爆炸与冲击,2011,31(3):326-331.CHENG Lei,HAN Yan,WANG Jian,et al.Timefrequency representation analysis in underwater explosive shock wave signals based on an improved HHT method[J].Explosion and Shock Waves,2011,31(3):326-331.
[8]李成武,解北京,杨威,等.基于HHT法的煤冲击破坏SHPB测试信号去噪[J].煤炭学报,2012,37(11):1796-1802.LI Chengwu,XIE Beijing,YANG Wei,et al.Coal impact damage SHPB testing signal de-noising based on HHT method[J].Journal of China Coal Society,2012,37(11):1796-1802.
[9]李成武,解北京,杨威,等.煤冲击破坏过程中的近距离瞬变磁场变化特征研究[J].岩石力学与工程学报,2012,31(5):973-981.LI Chengwu,XIE Beijing,YANG Wei,et al.Characteristics of transient magnetic nearby field in process of coal impact damage[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(5):973-981.
[10]刘晓辉,张茹,刘建锋.不同应变率下煤岩冲击动力试验研究[J].煤炭学报,2012,37(9):1528-1534.LIU Xiaohui,ZHANG Ru,LIU Jianfeng.Dynamic test study of coal rock under different strain rates[J].Journal of China Coal Society,2012,37(9):1528-1534.
[11]付玉凯,解北京,王启飞.煤的动态力学本构模型[J].煤炭学报,2013,38(10):1769-1774.FU Yukai,XIE Beijing,WANG Qifei.Dynamic mechanical constitutive model of coal[J].Journal of China Coal Society,2013,38(10):1769-1774.
[12]何学秋,刘明举.含瓦斯煤岩破坏电磁动力学[M].徐州:中国矿业大学出版社,1995.
[13]王恩元,何学秋.煤岩变形破裂电磁辐射的实验研究[J].地球物理学报,2000,43(1):131-137.WANG Enyuan,HE Xueqiu.A experimental study of the eletromagnetic emission during the deformation and fracture of coal or rock[J].China Journal of Geophysics,2000,43(1):131-137.
[14]王恩元,何学秋,刘贞堂,等.受载岩石电磁辐射特性及其应用研究[J].岩石力学与工程学报,2002,21(10):1473-1477.WANG Enyuan,HE Xueqiu,LIU Zhentang,et al.Study on electromagnetic emission characteristics of loaded rock and its applications[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(10):1473-1477.
[2]李希勇,张修峰.典型深部重大冲击地压事故原因分析及防治对策[J].煤炭科学技术,2003,31(2):15-17.LI Xiyong,ZHANG Xiufeng.Accident cause analysis and prevention measures of typical deep mine heavy pressure bump[J].Coal Science and Technology,2003,31(2):15-17.
[3]李胜林,刘殿书,李祥龙,等.Φ75mm分离式霍普金森压杆试件长度效应的试验研究[J].中国矿业大学学报,2010,39(1):93-97.LI Shenglin,LIU Dianshu,LI Xianglong,et al.The effect of specimen length inΦ75mm split Hopkinson pressure bar experiment[J].Journal of China University of Mining &Technology,2010,39(1):93-97.
[4]黄理兴,陈奕柏.我国岩石动力学研究状况与发展[J].岩石力学与工程学报,2003,22(11):1881-1886.HUANG Lixing,CHEN Yibai.Rock dynamics in China:past,present and future[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(11):1881-1886.
[5]黄理兴.岩石动力学研究成就与趋势[J].岩土力学,2011,32(10):2889-2900.HUANG Lixing.Development and new achievements of rock dynamics in China[J].Rock and Soil Mechanics,2011,32(10):2889-2900.
[6]撒占友,何学秋,王恩元.煤与瓦斯突出危险性电磁辐射异常判识方法[J].煤炭学报,2008,33(12):1373-1376.SA Zhanyou,HE Xueqiu,WANG Enyuan.EMR anomaly identification method of coal and gas outburst fatalness[J].Journal of China Coal Society,2008,33(12):1373-1376.
[7]程擂,韩焱,王鉴,等.基于改进HHT的水中爆炸冲击波信号时频特性分析方法[J].爆炸与冲击,2011,31(3):326-331.CHENG Lei,HAN Yan,WANG Jian,et al.Timefrequency representation analysis in underwater explosive shock wave signals based on an improved HHT method[J].Explosion and Shock Waves,2011,31(3):326-331.
[8]李成武,解北京,杨威,等.基于HHT法的煤冲击破坏SHPB测试信号去噪[J].煤炭学报,2012,37(11):1796-1802.LI Chengwu,XIE Beijing,YANG Wei,et al.Coal impact damage SHPB testing signal de-noising based on HHT method[J].Journal of China Coal Society,2012,37(11):1796-1802.
[9]李成武,解北京,杨威,等.煤冲击破坏过程中的近距离瞬变磁场变化特征研究[J].岩石力学与工程学报,2012,31(5):973-981.LI Chengwu,XIE Beijing,YANG Wei,et al.Characteristics of transient magnetic nearby field in process of coal impact damage[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(5):973-981.
[10]刘晓辉,张茹,刘建锋.不同应变率下煤岩冲击动力试验研究[J].煤炭学报,2012,37(9):1528-1534.LIU Xiaohui,ZHANG Ru,LIU Jianfeng.Dynamic test study of coal rock under different strain rates[J].Journal of China Coal Society,2012,37(9):1528-1534.
[11]付玉凯,解北京,王启飞.煤的动态力学本构模型[J].煤炭学报,2013,38(10):1769-1774.FU Yukai,XIE Beijing,WANG Qifei.Dynamic mechanical constitutive model of coal[J].Journal of China Coal Society,2013,38(10):1769-1774.
[12]何学秋,刘明举.含瓦斯煤岩破坏电磁动力学[M].徐州:中国矿业大学出版社,1995.
[13]王恩元,何学秋.煤岩变形破裂电磁辐射的实验研究[J].地球物理学报,2000,43(1):131-137.WANG Enyuan,HE Xueqiu.A experimental study of the eletromagnetic emission during the deformation and fracture of coal or rock[J].China Journal of Geophysics,2000,43(1):131-137.
[14]王恩元,何学秋,刘贞堂,等.受载岩石电磁辐射特性及其应用研究[J].岩石力学与工程学报,2002,21(10):1473-1477.WANG Enyuan,HE Xueqiu,LIU Zhentang,et al.Study on electromagnetic emission characteristics of loaded rock and its applications[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(10):1473-1477.