上保护层开采下煤岩强扰动力学行为与渗透特性
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摘要
保护层开采在低渗透高瓦斯近距离煤层中得到广泛应用,研究保护层开采扰动下的煤岩强扰动力学行为与渗透特性为进一步更加高效安全的开采被保护层煤层提供了理论支持。选取平煤集团十二矿上保护层己14煤层工作面己14-31010和被保护层己15煤层工作面己15-31030为研究对象,进行相似模拟试验和保护层开采过后被保护煤层受力分析。通过相似材料模拟试验获取保护层开采方式下被保护层的受力情况,上保护层开采过程中,煤层压力先增大后减小,采空区重新压实稳定后,应力状态近似恢复到原岩应力状态。通过对保护层开采后的被保护煤层受力分析获取煤层变形后的应力状态,上保护层开采过后,被保护层煤层产生变形,煤层上部分膨胀变形,应力小于原岩应力;下部分煤层压缩,应力大于原岩应力。结合二者的结果获取保护层开采方式下室内试验中被保护层煤层应力加载路径。依据被保护层煤层应力加载路径,设计进行采动耦合应力路径下的煤样渗流试验。试验结果表明:上保护层煤层开采过程中,同等试验条件下,被保护层煤层可承受的上保护层开采扰动应力越大,被保护层煤层开采过程中的煤体破坏应力峰值越大,体积应变越大;被保护层煤层开采过程中,M组煤样和N组煤样应力应变曲线与常规保护层卸荷三轴试验相比,扩容点出现位置明显提前;同等应力状态下,水压越大,煤样的体积应变越大;被保护层煤层开采过程中,M组煤样初始围压为35 MPa,围压对渗透率的影响大于轴压的影响,N组煤样初始围压为20 MPa,围压、轴压交替对渗透率产生主要影响,渗透率曲线呈现"W"型。两组试验中,扰动应力最大的试样破坏前的渗透率普遍大于其他试样的渗透率。
The method of protected coal seam mining has been widely used in low permeability,high gas and short distance coal seams. The research on mechanical behavior and permeability of coal and rock under strong mining disturbance in protected coal seam mining provides a theoretical support for further efficient and safe mining of protected seam. Taking the selection of the Ji14-31010 and Ji15-31030 mining face at the No.12 mine of Pingdingshan Shenma Group as a case study,the similar material simulation test and the stress analysis of the protected coal seam were carried out. The stress condition of the protected coal seam under the protected coal seam mining layout can be obtained by the similar material simulation test. During the mining process of the upper protective coal seam,the pressure of the coal seam increased initially and then decreased. After the goaf was re-compacted and stabilized,the stress state almost restored to the original rock stress state. The stress state of the coal seam after deformation is obtained by stress analysis of the protected coal seam. After mining of the upper protective seam,the protected coal seam has deformed. The top of the protected coal seam is less than that original rock stress,and the bottom of the protected coal seam is larger than the original rock stress. Combining with the similar material simulation test and the stress analysis of the protected coal seam,the stress loading path of the protected coal seam mining in laboratory test has been obtained. According to the stress loading path of the protected coal seam mining,the permeability test of mining coupled stress path has been designed and carried out. Through the experiments,some views can be concluded as follows. During the mining process of the upper protective coal seam,with the same experimental conditions,the larger the disturbance stress of the protected coal seam is,the larger the peak value of failure stress is,the smaller the confining pressure is,and the larger the volume strain is. During the mining process of protected coal seam mining,the expansion point on the stress-strain curves of M group coal samples and N group coal samples are much earlier than those of conventional unloading triaxial tests. With the same stress state,the larger the water pressure is,the larger the volume strain of coal is. During the mining process of protected coal seam mining,the initial confining pressure of M group coal sample is 35 MPa,the influence of confining pressure on permeability is greater than that of axial pressure. During the mining process of protected coal seam mining,the initial confining pressure of N group coal sample is 20 MPa,the alternation of confining pressure and axial pressure has the main effect on permeability. The permeability curve presents a "W" type. In both groups of experiments,the permeability of the sample with the largest disturbed stress is generally higher than that of other samples.
The method of protected coal seam mining has been widely used in low permeability,high gas and short distance coal seams. The research on mechanical behavior and permeability of coal and rock under strong mining disturbance in protected coal seam mining provides a theoretical support for further efficient and safe mining of protected seam. Taking the selection of the Ji14-31010 and Ji15-31030 mining face at the No.12 mine of Pingdingshan Shenma Group as a case study,the similar material simulation test and the stress analysis of the protected coal seam were carried out. The stress condition of the protected coal seam under the protected coal seam mining layout can be obtained by the similar material simulation test. During the mining process of the upper protective coal seam,the pressure of the coal seam increased initially and then decreased. After the goaf was re-compacted and stabilized,the stress state almost restored to the original rock stress state. The stress state of the coal seam after deformation is obtained by stress analysis of the protected coal seam. After mining of the upper protective seam,the protected coal seam has deformed. The top of the protected coal seam is less than that original rock stress,and the bottom of the protected coal seam is larger than the original rock stress. Combining with the similar material simulation test and the stress analysis of the protected coal seam,the stress loading path of the protected coal seam mining in laboratory test has been obtained. According to the stress loading path of the protected coal seam mining,the permeability test of mining coupled stress path has been designed and carried out. Through the experiments,some views can be concluded as follows. During the mining process of the upper protective coal seam,with the same experimental conditions,the larger the disturbance stress of the protected coal seam is,the larger the peak value of failure stress is,the smaller the confining pressure is,and the larger the volume strain is. During the mining process of protected coal seam mining,the expansion point on the stress-strain curves of M group coal samples and N group coal samples are much earlier than those of conventional unloading triaxial tests. With the same stress state,the larger the water pressure is,the larger the volume strain of coal is. During the mining process of protected coal seam mining,the initial confining pressure of M group coal sample is 35 MPa,the influence of confining pressure on permeability is greater than that of axial pressure. During the mining process of protected coal seam mining,the initial confining pressure of N group coal sample is 20 MPa,the alternation of confining pressure and axial pressure has the main effect on permeability. The permeability curve presents a "W" type. In both groups of experiments,the permeability of the sample with the largest disturbed stress is generally higher than that of other samples.
引文
[1]宋振骐,刘义学,陈孟伯,等.岩梁裂断前后的支承压力显现及其应用的探讨[J].山东矿业学院学报,1984(1):27-39.SONG Zhenqi,LIU Yixue,CHEN Mengbo,et al.Discussion on the manifestation of abutment pressure before and after rock beam fracture and its application[J].Shandong Mining Institute Journal,1984(1):27-39.
[2]KAISER P K,KORPACH D.Stress changes near the face of underground excavations[A].Proceedings of the International Symposium on Rock Stress and Rock Stress Measurements[C].1986:635-645.
[3]LEMON A M,JONES N L.Building solid models from boreholes and user-defined cross-sections[J].Computers&Geosciences,2003,29(5):547-555.
[4]JOHN G H,HANI S M.Numerical modeling of ore dilution in blasthole stoping[J].International Journal of Rock Mechanics and Mining Sciences,2007,44(5):692-703.
[5]谢和平,周宏伟,刘建锋,等.不同开采条件下采动力学行为研究[J].煤炭学报,2011,36(7):1067-1074.XIE Heping,ZHOU Hongwei,LIU Jianfeng,et al.Mining-induced mechanical behavior in coal seams under different mining layouts[J].Journal of China Coal Society,2011,36(7):1067-1074.
[6]谢和平,张泽天,高峰,等.不同开采方式下煤岩应力场-裂隙场-渗流场行为研究[J].煤炭学报,2016,41(10):2405-2417.XIE Heping,ZHANG Zetian,GAO Feng,et al.Stress-fracture-seepage field behavior of coal under different mining layouts[J].Journal of China Coal Society,2016,41(10):2405-2417.
[7]SEVKET Durucan.An investigation into the stress-permeability relationship of coals and flow patterns around working longwall faces[D].Nottingham UK:University of Nottingham,1981.
[8]薛熠.采动影响下损伤破裂煤岩体渗透性演化规律研究[D].徐州:中国矿业大学,2017:97-116.XUE Yi.Study on the permeability evolution of fractured coal under the influence of mining[D].Xuzhou:China University of Mining and Technology,2017:97-116.
[9]ZHANG Chunhui,WANG Laigui,DU Jianhua,et al.Numerical modeling rock deformation subject to nitrogen cooling to study permeability evolution[J].International Journal of Coal Science&Technology,2015,2(4):293-298.
[10]ZHANG Z,ZHANG R,XIE H,et al.Mining-induced coal permeability change under different mining layouts[J].Rock Mechanics and Rock Engineering,2016,49(9):3753-3768.
[11]荣腾龙,周宏伟,王路军,等.三向应力条件下煤体渗透率演化模型研究[J].煤炭学报,2018,43(7):1930-1937.RONG Tenglong,ZHOU Hongwei,WANG Lujun,et al.Coal permeability model for gas movement under the three-dimensional stress[J].Journal of China Coal Society,2018,43(7):1930-1937.
[12]宋常胜.超远距离下保护层开采卸压裂隙演化及渗流特征研究[D].焦作:河南理工大学,2012:113-132.SONG Changsheng.Research on the stress relief and fissure evolution and seepage flow characteristics for the lower protective seam mining with large interburden[D].Jiaozuo:Henan Plytechnic University,2012:113-132.
[13]PANG Yihui,WANG Guofa,DING Ziwei.Mechanical model of water inrush from coal seam floor based on triaxial seepage experiments[J].International Journal of Coal Science&Technology,2014,1(4):428-433.
[14]尹光志,蒋长宝,王维忠,等.不同卸围压速度对含瓦斯煤岩力学和瓦斯渗流特性影响试验研究[J].岩石力学与工程学报,2011,30(1):68-77.YIN Guangzhi,JIANG Changbao,WANG Weizhong,et al.Experimental study of influence of confining pressure unloading speed on mechanical properties and gas permeability of containinggas coal rock[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(1):68-77.
[15]薛东杰,周宏伟,孔琳,等.采动条件下被保护层瓦斯卸压增透机理研究[J].岩土工程学报,2012,34(10):1910-1916.XUE Dongjie,ZHOU Hongwei,KONG Lin,et al.Mechanism of unloading-induced permeability increment of protected coal seam under mining[J].Chinese Journal of Geotechnical Engineering,2012,34(10):1910-1916.
[16]PAN Z,CONNELL L D.Modelling permeability for coal reservoirs:A review of analytical models and testing data[J].International Journal of Coal Geology,2012,92:1-44.
[17]TAN Xin.Hydro-mechanical coupled behavior of Brittle rocks-laboratory experiments and numerical simulations[D].Freiberg Germany:Universit?t Bergakademie Freiberg,2013:134-164.
[18]李鸿昌.矿山压力的相似模拟试验[M].徐州:中国矿业大学出版社,1987.
[19]林韵梅.实验岩石力学[M].北京:煤炭工业出版社,1984.
[20]徐挺.相似理论与模型试验[M].北京:中国农业机械出版社,1982.
[21]张建全,闫保金,廖国华.采动覆岩移动规律的相似模拟实验研究[J].金属矿山,2002(8):10-12,39.ZHANG Jianquan,YAN Baojin,LIAO Guohua.Study on the overlying rock movement by equivalent material simulation[J].Metal Mine,2002(8):10-12,39.
[22]钱鸣高,石平五,许家林.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2010.
[23]邹航,刘建锋,边宇,等.不同粒度砂岩力学和渗透特性实验研究[J].岩土工程学报,2015,37(8):1462-1468.ZOU Hang,LIU Jianfeng,BIAN Yu,et al.Experimental study on mechanical and permeability properties of sandstone with different granularities[J].Chinese Journal of Geotechnical Engineering,2015,37(8):1462-1468.
[2]KAISER P K,KORPACH D.Stress changes near the face of underground excavations[A].Proceedings of the International Symposium on Rock Stress and Rock Stress Measurements[C].1986:635-645.
[3]LEMON A M,JONES N L.Building solid models from boreholes and user-defined cross-sections[J].Computers&Geosciences,2003,29(5):547-555.
[4]JOHN G H,HANI S M.Numerical modeling of ore dilution in blasthole stoping[J].International Journal of Rock Mechanics and Mining Sciences,2007,44(5):692-703.
[5]谢和平,周宏伟,刘建锋,等.不同开采条件下采动力学行为研究[J].煤炭学报,2011,36(7):1067-1074.XIE Heping,ZHOU Hongwei,LIU Jianfeng,et al.Mining-induced mechanical behavior in coal seams under different mining layouts[J].Journal of China Coal Society,2011,36(7):1067-1074.
[6]谢和平,张泽天,高峰,等.不同开采方式下煤岩应力场-裂隙场-渗流场行为研究[J].煤炭学报,2016,41(10):2405-2417.XIE Heping,ZHANG Zetian,GAO Feng,et al.Stress-fracture-seepage field behavior of coal under different mining layouts[J].Journal of China Coal Society,2016,41(10):2405-2417.
[7]SEVKET Durucan.An investigation into the stress-permeability relationship of coals and flow patterns around working longwall faces[D].Nottingham UK:University of Nottingham,1981.
[8]薛熠.采动影响下损伤破裂煤岩体渗透性演化规律研究[D].徐州:中国矿业大学,2017:97-116.XUE Yi.Study on the permeability evolution of fractured coal under the influence of mining[D].Xuzhou:China University of Mining and Technology,2017:97-116.
[9]ZHANG Chunhui,WANG Laigui,DU Jianhua,et al.Numerical modeling rock deformation subject to nitrogen cooling to study permeability evolution[J].International Journal of Coal Science&Technology,2015,2(4):293-298.
[10]ZHANG Z,ZHANG R,XIE H,et al.Mining-induced coal permeability change under different mining layouts[J].Rock Mechanics and Rock Engineering,2016,49(9):3753-3768.
[11]荣腾龙,周宏伟,王路军,等.三向应力条件下煤体渗透率演化模型研究[J].煤炭学报,2018,43(7):1930-1937.RONG Tenglong,ZHOU Hongwei,WANG Lujun,et al.Coal permeability model for gas movement under the three-dimensional stress[J].Journal of China Coal Society,2018,43(7):1930-1937.
[12]宋常胜.超远距离下保护层开采卸压裂隙演化及渗流特征研究[D].焦作:河南理工大学,2012:113-132.SONG Changsheng.Research on the stress relief and fissure evolution and seepage flow characteristics for the lower protective seam mining with large interburden[D].Jiaozuo:Henan Plytechnic University,2012:113-132.
[13]PANG Yihui,WANG Guofa,DING Ziwei.Mechanical model of water inrush from coal seam floor based on triaxial seepage experiments[J].International Journal of Coal Science&Technology,2014,1(4):428-433.
[14]尹光志,蒋长宝,王维忠,等.不同卸围压速度对含瓦斯煤岩力学和瓦斯渗流特性影响试验研究[J].岩石力学与工程学报,2011,30(1):68-77.YIN Guangzhi,JIANG Changbao,WANG Weizhong,et al.Experimental study of influence of confining pressure unloading speed on mechanical properties and gas permeability of containinggas coal rock[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(1):68-77.
[15]薛东杰,周宏伟,孔琳,等.采动条件下被保护层瓦斯卸压增透机理研究[J].岩土工程学报,2012,34(10):1910-1916.XUE Dongjie,ZHOU Hongwei,KONG Lin,et al.Mechanism of unloading-induced permeability increment of protected coal seam under mining[J].Chinese Journal of Geotechnical Engineering,2012,34(10):1910-1916.
[16]PAN Z,CONNELL L D.Modelling permeability for coal reservoirs:A review of analytical models and testing data[J].International Journal of Coal Geology,2012,92:1-44.
[17]TAN Xin.Hydro-mechanical coupled behavior of Brittle rocks-laboratory experiments and numerical simulations[D].Freiberg Germany:Universit?t Bergakademie Freiberg,2013:134-164.
[18]李鸿昌.矿山压力的相似模拟试验[M].徐州:中国矿业大学出版社,1987.
[19]林韵梅.实验岩石力学[M].北京:煤炭工业出版社,1984.
[20]徐挺.相似理论与模型试验[M].北京:中国农业机械出版社,1982.
[21]张建全,闫保金,廖国华.采动覆岩移动规律的相似模拟实验研究[J].金属矿山,2002(8):10-12,39.ZHANG Jianquan,YAN Baojin,LIAO Guohua.Study on the overlying rock movement by equivalent material simulation[J].Metal Mine,2002(8):10-12,39.
[22]钱鸣高,石平五,许家林.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2010.
[23]邹航,刘建锋,边宇,等.不同粒度砂岩力学和渗透特性实验研究[J].岩土工程学报,2015,37(8):1462-1468.ZOU Hang,LIU Jianfeng,BIAN Yu,et al.Experimental study on mechanical and permeability properties of sandstone with different granularities[J].Chinese Journal of Geotechnical Engineering,2015,37(8):1462-1468.
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