隧道瞬变电磁超前探测“双侧低阻”型干扰的成因分析和对策探讨
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摘要
贵州是全国唯一没有平原的省份,地质情况复杂且岩溶广泛分布,隧道建设过程中因为缺少相关地质资料,经常会发生岩溶突水、冒顶事故等。如何高效地做好隧道超前预测工作是勘察工作面临的一个重大难题,直接影响到设计、施工的有效性和安全性。瞬变电磁超前探测具有高效性、便携性、体积效应小等优点,是目前隧道超前预测预报的主要手段之一。在使用瞬变电磁法进行隧道超前预报的过程中发现了一个比较有规律的现象:隧道巷道两侧的探测反演图像形如蝴蝶的翅膀,即在两侧出现较为明显的对称低阻异常区域。但通过开挖揭露验证,巷道两侧岩体的分布和稳定性往往是正常的。分析出现这种情况是由于测线的旋转角、背景场的差异、金属干扰及信号衰减等原因,是多种因素相互作用的动态表现,可通过改进探测方法和调整参数予以解决。在实践过程中,将掌子面分为左帮、迎头、右帮3个部分,进行分区探测和数据采集,不仅增加了数据量,也方便后期将数据分段处理后叠加在统一的背景场下,以满足探测是基于均匀背景下建构的理论。采用改进的探测方法后,对比常规探测方法,反演图像视电阻率整体较高,且稳定连续,未发现异常现象,与实际地质情况相符。
The paper has found that there exists a more obvious symmetrically low resistivity in the anomalous area on the both sides of the tunnel forecast. And we have analyzed the reasons for the phenomena involved,such as the rotation angle of the measuring line,the difference of the background field,the metal interference and the signal attenuation,etc.,due to the dynamic performance of the interaction of the various factors,which has to be solved by improving the detection method and adjusting the related parameters. In dealing with the problem,we have managed to adopt the method of " semi-circular detection" by dividing the conventional acquisition mode into 3 parts,and the tunnel face into 3 zones: that is,the left side,the front side and the right side. Along the line,we have collected the data involved in the said 3 directions: that is,the 45° of the elevation angle,the horizontal direction,and the 45° of the depression angle,which can not only account for the increase of the data size and varieties,but also include the premise of the background field superimposing and unification through data segmentation. At the same time,it should also satisfy the theory for the detection based on the uniform background construction so as to ensure the relative accuracy of the inversion results. And,then,when the improved detection method has been adopted,and compared with the conventional detection ones,the inversion image apparent resistivity has been found overall higher. What is more,it proves stable and continuous,with no abnormal phenomena found,and consistent with the actual geological conditions.
The paper has found that there exists a more obvious symmetrically low resistivity in the anomalous area on the both sides of the tunnel forecast. And we have analyzed the reasons for the phenomena involved,such as the rotation angle of the measuring line,the difference of the background field,the metal interference and the signal attenuation,etc.,due to the dynamic performance of the interaction of the various factors,which has to be solved by improving the detection method and adjusting the related parameters. In dealing with the problem,we have managed to adopt the method of " semi-circular detection" by dividing the conventional acquisition mode into 3 parts,and the tunnel face into 3 zones: that is,the left side,the front side and the right side. Along the line,we have collected the data involved in the said 3 directions: that is,the 45° of the elevation angle,the horizontal direction,and the 45° of the depression angle,which can not only account for the increase of the data size and varieties,but also include the premise of the background field superimposing and unification through data segmentation. At the same time,it should also satisfy the theory for the detection based on the uniform background construction so as to ensure the relative accuracy of the inversion results. And,then,when the improved detection method has been adopted,and compared with the conventional detection ones,the inversion image apparent resistivity has been found overall higher. What is more,it proves stable and continuous,with no abnormal phenomena found,and consistent with the actual geological conditions.
引文
[1] RAICHE A P,BENNETT L A. Layered earth models using downhole electromagnetic receivers[J]. Exploration Geophysics,1987,18(3):762-769.
[2] NIU Zhilian(牛之琏). Theory of time domain electromagnetic method(时间域电磁法原理)[M]. Changsha:Central South University Press,2007:1-2.
[3] WOODS D V. A model study of the crone borehole pulse electromagnetic(PEM)system[D]. Belfast:Queen's University,1975.
[4] KAUFMAN A A,KELLER G V. Inductive mining prospecting. Part 1:Theory[M]. Amsterdam:Elsevier,1985.
[5] NABIGHIAN M N. Quasi-static transient response of a conducting half-space—an approximate representation[J]. Geophysics,1979,44(10):1700-1705.
[6] NIU Zhilian(牛之琏). Pulse transient electromagnetic method and application(脉冲瞬变电磁法及应用)[M].Changsha:Central South University Press,1986.
[7] PIAO Huarong(朴化荣). Principle of electromagnetic sounding method(电磁测深法原理)[M]. Beijing:Geological Publishing House,1990.
[8] YIN Changchun(殷长春),PIAO Huarong(朴化荣). A study of the definition of apparent resistivity in electromagnetic sounding[J]. Geophysical and Geochemical Exploration(物探与化探),1991,15(4):290-299.
[9] YU Jingcun(于景邨),LIU Zhixin(刘志新),LIU Shucai(刘树才),et al. Theoretical analysis of mine transient electromagnetic method[J]. Journal of China Coal Society(煤炭学报),2007,32(8):818-821.
[10] JIANG Zhihai(姜志海),YUE Jianhua(岳建华),LIU Zhixin(刘志新). Mine transient electromagnetic method to leading exploration in the old kiln water application[J]. Chinese Journal of Engineering Geophysics(工程地球物理学报),2007,4(4):292-294.
[11] LIU Zhixin(刘志新),LIU Shucai(刘树才),LIU Yangguang(刘仰光). Mine rich water bodies of physical model experiment tem field[J]. Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2009,28(2):259-266.
[12] LI Xiu(李貅),WU Junjie(武军杰),CAO Daming(曹大明),et al. Advanced geologic forecasting for unfavorable geological body with water—transient electromagnetic method[J]. Journal of Geotechnical Investigation&Surveying(工程勘察),2006(3):70-75.
[13] LI Shucai(李术才),LIU Bin(刘斌),SUN Huaifeng(孙怀风),et al. State of art and trends of advanced geological prediction in tunnel construction[J]. Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2014,33(6):1090-1113.
[14] SU Maoxin(苏茂鑫),LI Shucai(李术才),XUE Yiguo(薛诩国),et al. Tunnel geological prediction of the transient electromagnetic method of apparent vertical conductance study[J]. Chinese Journal of Geotechnical Engineering(岩土工程学报), 2010, 32(11):1722-1726.
[15] LIU Wensheng(刘文生),WU Zuoqi(吴作启),LI Fanyue(李凡月),et al. On the fracturing mechanism of the igneous rock overlying the goaf[J]. Journal of Safety and Environment(安全与环境学报),2017,17(1):54-58.
[16] JIA Sanshi(贾三石),WANG Ende(王恩德),FU Jianfei(付建飞),et al. On the detection means and methods for the submersible goafs in the open-pit iron mine[J]. Journal of Safety and Environment(安全与环境学报),2018,18(6):2195-2199.
[17] SUN Huaifeng(孙怀凤). Three-dimensional transient electromagnetic responses of water bearing structures in tunnels and prediction of water inrush sources(隧道含水构造三维瞬变电磁场响应特征及突水灾害源预报研究)[D]. Jinan:Shandong University,2013.
[18] JIAO Xianfeng(焦险峰),LIU Zhixin(刘志新). Physical model and experimental research on shallow resolution of transient electromagnetic method[J]. Journal of China University of Mining&Technology(中国矿业大学学报),2014,43(4):738-741.
[19] SU Maoxin(苏茂鑫),QIAN Qihu(钱七虎),LI Shucai(李术才),et al. A method of metro advanced geological prediction under karst geology condition[J]. Chinese Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2011,30(7):1428-1434.
[20] LIU Shucai(刘树才),LIU Zhixin(刘志新),JANG Zhihai(姜志海). Application of TEM to hydrogeological prospecting of mining district[J]. Journal of China University of Mining and Technology(中国矿业大学学报),2005,34(4):414-417.
[21] YUE Jianhua(岳建华),YANG Haiyan(杨海燕). Research on response of transient electromagnetic field in underground mine with boundary condition of laneway[J]. Journal of China University of Mining and Technology(中国矿业大学学报),2008,37(2):152-156.
[22] LI Xiu(李貅). Theory and application of transient electromagnetic sounding(瞬变电磁测深的理论与应用)[M]. Xi'an:Shaanxi Science and Technology Press,2002:1-4.
[2] NIU Zhilian(牛之琏). Theory of time domain electromagnetic method(时间域电磁法原理)[M]. Changsha:Central South University Press,2007:1-2.
[3] WOODS D V. A model study of the crone borehole pulse electromagnetic(PEM)system[D]. Belfast:Queen's University,1975.
[4] KAUFMAN A A,KELLER G V. Inductive mining prospecting. Part 1:Theory[M]. Amsterdam:Elsevier,1985.
[5] NABIGHIAN M N. Quasi-static transient response of a conducting half-space—an approximate representation[J]. Geophysics,1979,44(10):1700-1705.
[6] NIU Zhilian(牛之琏). Pulse transient electromagnetic method and application(脉冲瞬变电磁法及应用)[M].Changsha:Central South University Press,1986.
[7] PIAO Huarong(朴化荣). Principle of electromagnetic sounding method(电磁测深法原理)[M]. Beijing:Geological Publishing House,1990.
[8] YIN Changchun(殷长春),PIAO Huarong(朴化荣). A study of the definition of apparent resistivity in electromagnetic sounding[J]. Geophysical and Geochemical Exploration(物探与化探),1991,15(4):290-299.
[9] YU Jingcun(于景邨),LIU Zhixin(刘志新),LIU Shucai(刘树才),et al. Theoretical analysis of mine transient electromagnetic method[J]. Journal of China Coal Society(煤炭学报),2007,32(8):818-821.
[10] JIANG Zhihai(姜志海),YUE Jianhua(岳建华),LIU Zhixin(刘志新). Mine transient electromagnetic method to leading exploration in the old kiln water application[J]. Chinese Journal of Engineering Geophysics(工程地球物理学报),2007,4(4):292-294.
[11] LIU Zhixin(刘志新),LIU Shucai(刘树才),LIU Yangguang(刘仰光). Mine rich water bodies of physical model experiment tem field[J]. Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2009,28(2):259-266.
[12] LI Xiu(李貅),WU Junjie(武军杰),CAO Daming(曹大明),et al. Advanced geologic forecasting for unfavorable geological body with water—transient electromagnetic method[J]. Journal of Geotechnical Investigation&Surveying(工程勘察),2006(3):70-75.
[13] LI Shucai(李术才),LIU Bin(刘斌),SUN Huaifeng(孙怀风),et al. State of art and trends of advanced geological prediction in tunnel construction[J]. Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2014,33(6):1090-1113.
[14] SU Maoxin(苏茂鑫),LI Shucai(李术才),XUE Yiguo(薛诩国),et al. Tunnel geological prediction of the transient electromagnetic method of apparent vertical conductance study[J]. Chinese Journal of Geotechnical Engineering(岩土工程学报), 2010, 32(11):1722-1726.
[15] LIU Wensheng(刘文生),WU Zuoqi(吴作启),LI Fanyue(李凡月),et al. On the fracturing mechanism of the igneous rock overlying the goaf[J]. Journal of Safety and Environment(安全与环境学报),2017,17(1):54-58.
[16] JIA Sanshi(贾三石),WANG Ende(王恩德),FU Jianfei(付建飞),et al. On the detection means and methods for the submersible goafs in the open-pit iron mine[J]. Journal of Safety and Environment(安全与环境学报),2018,18(6):2195-2199.
[17] SUN Huaifeng(孙怀凤). Three-dimensional transient electromagnetic responses of water bearing structures in tunnels and prediction of water inrush sources(隧道含水构造三维瞬变电磁场响应特征及突水灾害源预报研究)[D]. Jinan:Shandong University,2013.
[18] JIAO Xianfeng(焦险峰),LIU Zhixin(刘志新). Physical model and experimental research on shallow resolution of transient electromagnetic method[J]. Journal of China University of Mining&Technology(中国矿业大学学报),2014,43(4):738-741.
[19] SU Maoxin(苏茂鑫),QIAN Qihu(钱七虎),LI Shucai(李术才),et al. A method of metro advanced geological prediction under karst geology condition[J]. Chinese Journal of Rock Mechanics and Engineering(岩石力学与工程学报),2011,30(7):1428-1434.
[20] LIU Shucai(刘树才),LIU Zhixin(刘志新),JANG Zhihai(姜志海). Application of TEM to hydrogeological prospecting of mining district[J]. Journal of China University of Mining and Technology(中国矿业大学学报),2005,34(4):414-417.
[21] YUE Jianhua(岳建华),YANG Haiyan(杨海燕). Research on response of transient electromagnetic field in underground mine with boundary condition of laneway[J]. Journal of China University of Mining and Technology(中国矿业大学学报),2008,37(2):152-156.
[22] LI Xiu(李貅). Theory and application of transient electromagnetic sounding(瞬变电磁测深的理论与应用)[M]. Xi'an:Shaanxi Science and Technology Press,2002:1-4.