偶极接地线对地电阻率影响的数值模拟
|
摘要
针对我国地震监测预报中地电阻率定点连续观测中存在的偶极接地线的干扰问题,本文将台站区域地层简化为3层均匀介质模型,将接地线等效为偶极接地的电阻体,建立了接地线干扰地电阻率观测的耦合物理模型.通过有限元分析软件ANSYS模拟分析不同电性断面情况下接地线对地电阻率观测的影响,同时分析这种干扰的产生机理,并结合实际观测中存在的干扰问题作了对比验证分析.结果表明:1接地线使得供电电极产生的地下对称性电场分布发生局部调整,从而影响地电阻率观测;2接地线对地电阻率观测的影响主要取决于线缆的位置及方位角的大小;3适当增大电极埋深可以减小其对地电阻率观测的影响;4电性结构的差异性决定干扰变化幅度的大小.本文结果对相关台站地电阻率观测异常分析落实及干扰源避让和观测系统改造具有参考意义.
Two-end grounded cables often generate interference to continuous georesistivity observation at fixed sites for earthquake monitoring and prediction in China.By taking the grounded cables as two-end grounded resistors and simplifying the medium of geoelectric observation sites into horizontally inhomogeneous three-layered medium,a coupled physical model is built up in this paper.Based on this model,influences of two-end grounded cables on georesistivity observation are simulated under different electric structures by using the finite element analysis software ANSYS.Furthermore,the effects of interference factors,such as position,azimuth and buried depth of electrodes,on georesistivity observation are analyzed.And the interference mechanisms are also discussed.Besides,some existing interferences are also presented to give out a comparative study.The results showed that the first,the grounded cables can cause local adjustment of the symmetric underground electric field distribution generated by the current electrode,affecting normal georesistivity observation;the second,the effects of grounded cables on georesistivity observation,mainly depend on position of cables and their azimuth;the third,the effects tend to be reduced obviously with buried depth of electrodes increasing;and the forth,the difference of the electric structures determine the magnitude of interference.The simulation results are of significance as a reference to analyzing the similar resistivity anomalies,choosing the evaded distance of the interference source and the reform of the observing system.
Two-end grounded cables often generate interference to continuous georesistivity observation at fixed sites for earthquake monitoring and prediction in China.By taking the grounded cables as two-end grounded resistors and simplifying the medium of geoelectric observation sites into horizontally inhomogeneous three-layered medium,a coupled physical model is built up in this paper.Based on this model,influences of two-end grounded cables on georesistivity observation are simulated under different electric structures by using the finite element analysis software ANSYS.Furthermore,the effects of interference factors,such as position,azimuth and buried depth of electrodes,on georesistivity observation are analyzed.And the interference mechanisms are also discussed.Besides,some existing interferences are also presented to give out a comparative study.The results showed that the first,the grounded cables can cause local adjustment of the symmetric underground electric field distribution generated by the current electrode,affecting normal georesistivity observation;the second,the effects of grounded cables on georesistivity observation,mainly depend on position of cables and their azimuth;the third,the effects tend to be reduced obviously with buried depth of electrodes increasing;and the forth,the difference of the electric structures determine the magnitude of interference.The simulation results are of significance as a reference to analyzing the similar resistivity anomalies,choosing the evaded distance of the interference source and the reform of the observing system.
引文
安张辉,元丽华,李宁,范莹莹,谭大诚,陈军营,郑国磊.2010.HHT方法在地电场数据处理中的应用[J].地球物理学进展,25(2):525-532.
An Z H,Yuan L H,Li N,Fan Y Y,Tan D C,Chen J Y,Zheng G L.2010.Discussion on the application of HHTmethod to geoelectric field data processing[J].Progress in Geophysics,25(2):525-532(in Chinese).
安张辉,杜学彬,元丽华,谭大诚,陈军营.2011.HHT方法在受城市轨道交通干扰地电场观测数据中的应用[J].地震学报,33(2):243-251.
An Z H,Du X B,Yuan L H,Tan D C,Chen J Y.2011.Application of Hilbert-Huang transform to geo-electric data disturbed by urban track traffic[J].Acta Seismologica Sinica,33(2):243-251(in Chinese).
陈峰,修济刚,安金珍,廖椿庭,陈大元.2000.岩石电阻率变化各向异性与微裂隙扩展方位实验研究[J].地震学报,22(3):310-318.
Chen F,Xiu J G,An J Z,Liao C T,Chen D Y.2000.Research on dependence of resistivity changing anisotropy on microcracks extending in rock with experiment[J].Acta Seismologica Sinica,22(3):310-318(in Chinese).
杜学彬,李宁,叶青,马占虎,闫睿.2007.强地震附近视电阻率各向异性变化的原因[J].地球物理学报,50(6):1802-1810.
Du X B,Li N,Ye Q,Ma Z H,Yan R.2007.A possible reason for the anisotropic changes in apparent resistivity nearthe focal region of strong earthquake[J].Chinese Journal of Geophysics,50(6):1802-1810(in Chinese).
杜学彬,叶青,马占虎,李宁,陈军营,谭大诚.2008.强地震附近电阻率对称四极观测的探测深度[J].地球物理学报,51(6):1943-1949.
Du X B,Ye Q,Ma Z H,Li N,Chen J Y,Tan D C.2008.The detection depth of symmetric four-electrode resistivity observation in/near the epicentral region of strong earthquakes[J].Chinese Journal of Geophysics,51(6):1943-1949(in Chinese).
杜学彬.2010.在地震预报中的两类视电阻率变化[J].中国科学:地球科学,40(10):1321-1330.
Du X B.2011.Two types of changes in apparent resistivity in earthquake prediction[J].Science China:Earth Sciences,54(1):145-156.
方炜,张国强,邵辉成.2010.高压直流输电对地电场观测的影响[J].地震地质,32(3):434-441.
Fang W,Zhang G Q,Shao H C.2010.Study on the impact of HVDC to geoelectric field observation[J].Seismologyand Geology,32(3):434-441(in Chinese).
郝锦绮,冯锐,周建国,钱书清,高金田.2002.岩石破裂过程中电阻率变化机理的探讨[J].地球物理学报,45(3):426-434.
Hao J Q,Feng R,Zhou J G,Qian S Q,Gao J T.2002.Study on the mechanism of resistivity changes during rock cracking[J].Chinese Journal of Geophysics,45(3):426-434(in Chinese).
黄清华,林玉峰.2010.地震电信号选择性数值模拟及可能影响因素[J].地球物理学报,53(3):535-543.
Huang Q H,Lin Y F.2010.Numerical simulation of selectivity of seismic electric signal and its possible influences[J].Chinese Journal of Geophysics,53(3):535-543(in Chinese).
钱复业,赵玉林.1980.地震前地电阻率变化十例[J].地震学报,2(2):186-197.
Qian F Y,Zhao Y L.1980.The examples of changes in earth-resistivity prior to strong earthquakes[J].Acta Seismologica Sinica,2(2):186-197(in Chinese).
钱家栋.1993.与大震孕育过程有关的地电阻率变化研究[J].中国地震,9(4):341-350.
Qian J D.1993.A study on the changes in geoelectrical resistivity associated with preparatory process of great earthquakes in China[J].Earthquake Research in China,9(4):341-350(in Chinese).
汤井田,公劲喆.2010.三维直流电阻率有限元-无限元耦合数值模拟[J].地球物理学报,53(3):717-728.
Tang J T,Gong J Z.2010.3D DC resistivity forward modeling by finite-infinite element coupling method[J].ChineseJournal of Geophysics,53(3):717-728(in Chinese).
田山,刘允秀,聂永安,马骥,庞群英,杜学彬.2009.地震地电阻率观测改进方法研究:电测井技术的移植应用与数值模型分析[J].地震学报,31(3):272-281.
Tian S,Liu Y X,Nie Y A,Ma J,Pang Q Y,Du X B.2009.Improved method of earth resistivity observation:Transplant application and numerical model analysis of electric well logging technique[J].Acta Seismologica Sinica,31(3):272-281(in Chinese).
汪志亮,郑大林,余索荣.2002.地震地电阻率前兆异常现象[M].北京:地震出版社:51-79.
Wang Z L,Zheng D L,Yu S R.2002.Geoelectric Resistivity Precursor Anomalies of Earthquake[M].Beijing:Seismological Press:51-79(in Chinese).
卫定军,李春贵.2009.搭建蔬菜大棚对固原地电台视电阻率观测影响的分析[J].地震地磁观测与研究,30(2):77-82.
Wei D J,Li C G.2009.Analysis about influence of green house on apparent resistivity observation at Guyuan seismic station[J].Seismological and Geomagnetic Observation and Research,30(2):77-82(in Chinese).
解滔,杜学彬,陈军营,安张辉,谭大成,范莹莹,刘君.2012.井下地电阻率观测中地表电流干扰影响计算[J].地球物理学进展,27(1):112-121.
Xie T,Du X B,Chen J Y,An Z H,Tan D C,Fan Y Y,Liu J.2012.Calculation for the influence from the surface disturbance current in the deep-well geoelectrical resistivity observation[J].Progress in Geophysics,27(1):112-121(in Chinese).
解滔,卢军,李美,王中平,王亚丽.2013.地埋钢缆对宝昌台地电阻率干扰的定量分析[J].地球物理学进展,28(2):724-734.
Xie T,Lu J,Li M,Wang Z P,Wang Y L.2013.Quantitative analysis of disturbance caused by burned wirerope inBaochang geoelectric resistivity station[J].Progress in Geophysics,28(2):724-734(in Chinese).
杨兴悦,杨立明,康云生,安海静,郝臻,武银,王燕.2012.天水地震台井下地电观测系统介绍及其分析[J].地震研究,35(1):92-97.
Yang X Y,Yang L M,Kang Y S,An H J,Hao Z,Wu Y,Wang Y.2012.Introduction and analysis of geo-electrical observation system in underground well at Tianshui station[J].Journal of Seismological Research,35(1):92-97(inChinese).
叶青,杜学彬,陈军营,谭大成,马占虎.2005.2003年大姚和民乐-山丹地震1年尺度预测[J].地震研究,28(3):226-230.
Ye Q,Du X B,Chen J Y,Tan D C,Ma Z H.2005.One-year prediction for the Dayao and Minle-Shandan earthquakesin 2003[J].Journal of Seismological Research,28(3):226-230(in Chinese).
张世中,石航,王兰炜,胡哲,刘大鹏,魏连生,鞠永.2013.地电台站受城市轨道交通干扰的测试分析与抗干扰措施研究[J].地震学报,35(1):117-124.
Zhang S Z,Shi H,Wang L W,Hu Z,Liu D P,Wei L S,Ju Y.2013.Test analysis on disturbances caused by urban railtransit at geoelectric stations and measures to reduce its influence[J].Acta Seismologica Sinica,35(1):117-124(inChinese).
张秀霞,李飞,杨冯威,孙春仙,肖飞.2009.蔬菜大棚对新沂地震台地电阻率的影响[J].地震地磁观测与研究,30(增刊):32-36.
Zhang X X,Li F,Yang F W,Sun C X,Xiao F.2009.About the effect of the vegetable shelter for the earth resistivityat Xinyi seismic station[J].Seismological and Geomagnetic Observation and Research,30(Suppl.):32-36(in Chinese).
Balasco M,Colangelo G,Lapenna V,Loddo M,Siniscalchi A,Telesca L.2004.Measuring apparent resistivity in a seismically active area of southern Italy[J].Phys Chem Earth,Parts A/B/C,29(4/5/6/7/8/9):329-337.
Brace W F,Orange A S.1968.Electrical resistivity changes in saturated rocks during fracture and frictional sliding[J].JGeophys Res,73(4):1433-1445.
Busby J P.2000.The effectiveness of azimuthal apparent-resistivity measurements as a method for determining fracturestrike orientations[J].Geophys Prospect,48(4):677-695.
Du X B,Xue S Z,Hao Z,Zhang S Z.2000.On the relation of moderate-short term anomaly of earth resistivity to earthquake[J].Acta Seismological Sinica,13(4):393-403.
Huang Q H,Lin Y F.2010.Selectivity of seismic electric signal(SES)of the 2000Izu earthquake swarm:A 3DFEMnumerical simulation model[J].Proc Japan Acad:Series B,86(3):257-264.
Lu J,Qian F Y,Zhao Y L.1999.Sensitivity analysis of the Schlumberger monitoring array:Application to changes ofresistivity prior to the 1976earthquake in Tangshan,China[J].Tectonophysics,307(3/4):397-405.
Lu J,Xue S Z,Qian F Y,Zhao Y L,Guan H P,Mao X J,Ruan A G,Yu S R,Xiao W J.2004.Unexpected changesin resistivity monitoring for earthquakes of the Longmen Shan in Sichuan,China,with a fixed Schlumberger soundingarray[J].Phys Earth Planet Inter,145(1/2/3/4):87-97.
Park S K,Johnston M J S,Madden T R,Morgan F D,Morrison H F.1993.Electromagnetic precursors to earthquakesin the ULF band:A review of observations and mechanisms[J].Rev Geophys,31(2):117-132.
Qian F Y,Zhao Y L,Huang Y N.1996.Calculation of the parameters of georesistivity anisotropy and case history ofearthquake precursors[J].Acta Seismologica Sinica,9(4):617-627.
Scholz C H,Sykes L R,Aggarwal Y P.1973.Earthquake prediction:A physical basis[J].Science,181(4102):803-810.
Wang C Y,Goodman R E,Sundaram P N,Morrison H F.1975.Electrical resistivity of granite in frictional sliding:Application to earthquake prediction[J].Geophys Res Lett,2(12):525-528.
Wang C Y,Sundaram P N,Goodman R E.1978.Electrical resistivity changes in rocks during frictional sliding and fracture[J].Pure Appl Geophys,116(4/5):717-731.
Yang C H,Cheng P H,You J I,Tsai L L.2002.Significant resistivity changes in the fault zone associated with the 1999Chi-Chi earthquake,west-central Taiwan[J].Tectonophysics,350(4):299-313.
1据2013年全国电磁会商会相关单位资料报告.
An Z H,Yuan L H,Li N,Fan Y Y,Tan D C,Chen J Y,Zheng G L.2010.Discussion on the application of HHTmethod to geoelectric field data processing[J].Progress in Geophysics,25(2):525-532(in Chinese).
安张辉,杜学彬,元丽华,谭大诚,陈军营.2011.HHT方法在受城市轨道交通干扰地电场观测数据中的应用[J].地震学报,33(2):243-251.
An Z H,Du X B,Yuan L H,Tan D C,Chen J Y.2011.Application of Hilbert-Huang transform to geo-electric data disturbed by urban track traffic[J].Acta Seismologica Sinica,33(2):243-251(in Chinese).
陈峰,修济刚,安金珍,廖椿庭,陈大元.2000.岩石电阻率变化各向异性与微裂隙扩展方位实验研究[J].地震学报,22(3):310-318.
Chen F,Xiu J G,An J Z,Liao C T,Chen D Y.2000.Research on dependence of resistivity changing anisotropy on microcracks extending in rock with experiment[J].Acta Seismologica Sinica,22(3):310-318(in Chinese).
杜学彬,李宁,叶青,马占虎,闫睿.2007.强地震附近视电阻率各向异性变化的原因[J].地球物理学报,50(6):1802-1810.
Du X B,Li N,Ye Q,Ma Z H,Yan R.2007.A possible reason for the anisotropic changes in apparent resistivity nearthe focal region of strong earthquake[J].Chinese Journal of Geophysics,50(6):1802-1810(in Chinese).
杜学彬,叶青,马占虎,李宁,陈军营,谭大诚.2008.强地震附近电阻率对称四极观测的探测深度[J].地球物理学报,51(6):1943-1949.
Du X B,Ye Q,Ma Z H,Li N,Chen J Y,Tan D C.2008.The detection depth of symmetric four-electrode resistivity observation in/near the epicentral region of strong earthquakes[J].Chinese Journal of Geophysics,51(6):1943-1949(in Chinese).
杜学彬.2010.在地震预报中的两类视电阻率变化[J].中国科学:地球科学,40(10):1321-1330.
Du X B.2011.Two types of changes in apparent resistivity in earthquake prediction[J].Science China:Earth Sciences,54(1):145-156.
方炜,张国强,邵辉成.2010.高压直流输电对地电场观测的影响[J].地震地质,32(3):434-441.
Fang W,Zhang G Q,Shao H C.2010.Study on the impact of HVDC to geoelectric field observation[J].Seismologyand Geology,32(3):434-441(in Chinese).
郝锦绮,冯锐,周建国,钱书清,高金田.2002.岩石破裂过程中电阻率变化机理的探讨[J].地球物理学报,45(3):426-434.
Hao J Q,Feng R,Zhou J G,Qian S Q,Gao J T.2002.Study on the mechanism of resistivity changes during rock cracking[J].Chinese Journal of Geophysics,45(3):426-434(in Chinese).
黄清华,林玉峰.2010.地震电信号选择性数值模拟及可能影响因素[J].地球物理学报,53(3):535-543.
Huang Q H,Lin Y F.2010.Numerical simulation of selectivity of seismic electric signal and its possible influences[J].Chinese Journal of Geophysics,53(3):535-543(in Chinese).
钱复业,赵玉林.1980.地震前地电阻率变化十例[J].地震学报,2(2):186-197.
Qian F Y,Zhao Y L.1980.The examples of changes in earth-resistivity prior to strong earthquakes[J].Acta Seismologica Sinica,2(2):186-197(in Chinese).
钱家栋.1993.与大震孕育过程有关的地电阻率变化研究[J].中国地震,9(4):341-350.
Qian J D.1993.A study on the changes in geoelectrical resistivity associated with preparatory process of great earthquakes in China[J].Earthquake Research in China,9(4):341-350(in Chinese).
汤井田,公劲喆.2010.三维直流电阻率有限元-无限元耦合数值模拟[J].地球物理学报,53(3):717-728.
Tang J T,Gong J Z.2010.3D DC resistivity forward modeling by finite-infinite element coupling method[J].ChineseJournal of Geophysics,53(3):717-728(in Chinese).
田山,刘允秀,聂永安,马骥,庞群英,杜学彬.2009.地震地电阻率观测改进方法研究:电测井技术的移植应用与数值模型分析[J].地震学报,31(3):272-281.
Tian S,Liu Y X,Nie Y A,Ma J,Pang Q Y,Du X B.2009.Improved method of earth resistivity observation:Transplant application and numerical model analysis of electric well logging technique[J].Acta Seismologica Sinica,31(3):272-281(in Chinese).
汪志亮,郑大林,余索荣.2002.地震地电阻率前兆异常现象[M].北京:地震出版社:51-79.
Wang Z L,Zheng D L,Yu S R.2002.Geoelectric Resistivity Precursor Anomalies of Earthquake[M].Beijing:Seismological Press:51-79(in Chinese).
卫定军,李春贵.2009.搭建蔬菜大棚对固原地电台视电阻率观测影响的分析[J].地震地磁观测与研究,30(2):77-82.
Wei D J,Li C G.2009.Analysis about influence of green house on apparent resistivity observation at Guyuan seismic station[J].Seismological and Geomagnetic Observation and Research,30(2):77-82(in Chinese).
解滔,杜学彬,陈军营,安张辉,谭大成,范莹莹,刘君.2012.井下地电阻率观测中地表电流干扰影响计算[J].地球物理学进展,27(1):112-121.
Xie T,Du X B,Chen J Y,An Z H,Tan D C,Fan Y Y,Liu J.2012.Calculation for the influence from the surface disturbance current in the deep-well geoelectrical resistivity observation[J].Progress in Geophysics,27(1):112-121(in Chinese).
解滔,卢军,李美,王中平,王亚丽.2013.地埋钢缆对宝昌台地电阻率干扰的定量分析[J].地球物理学进展,28(2):724-734.
Xie T,Lu J,Li M,Wang Z P,Wang Y L.2013.Quantitative analysis of disturbance caused by burned wirerope inBaochang geoelectric resistivity station[J].Progress in Geophysics,28(2):724-734(in Chinese).
杨兴悦,杨立明,康云生,安海静,郝臻,武银,王燕.2012.天水地震台井下地电观测系统介绍及其分析[J].地震研究,35(1):92-97.
Yang X Y,Yang L M,Kang Y S,An H J,Hao Z,Wu Y,Wang Y.2012.Introduction and analysis of geo-electrical observation system in underground well at Tianshui station[J].Journal of Seismological Research,35(1):92-97(inChinese).
叶青,杜学彬,陈军营,谭大成,马占虎.2005.2003年大姚和民乐-山丹地震1年尺度预测[J].地震研究,28(3):226-230.
Ye Q,Du X B,Chen J Y,Tan D C,Ma Z H.2005.One-year prediction for the Dayao and Minle-Shandan earthquakesin 2003[J].Journal of Seismological Research,28(3):226-230(in Chinese).
张世中,石航,王兰炜,胡哲,刘大鹏,魏连生,鞠永.2013.地电台站受城市轨道交通干扰的测试分析与抗干扰措施研究[J].地震学报,35(1):117-124.
Zhang S Z,Shi H,Wang L W,Hu Z,Liu D P,Wei L S,Ju Y.2013.Test analysis on disturbances caused by urban railtransit at geoelectric stations and measures to reduce its influence[J].Acta Seismologica Sinica,35(1):117-124(inChinese).
张秀霞,李飞,杨冯威,孙春仙,肖飞.2009.蔬菜大棚对新沂地震台地电阻率的影响[J].地震地磁观测与研究,30(增刊):32-36.
Zhang X X,Li F,Yang F W,Sun C X,Xiao F.2009.About the effect of the vegetable shelter for the earth resistivityat Xinyi seismic station[J].Seismological and Geomagnetic Observation and Research,30(Suppl.):32-36(in Chinese).
Balasco M,Colangelo G,Lapenna V,Loddo M,Siniscalchi A,Telesca L.2004.Measuring apparent resistivity in a seismically active area of southern Italy[J].Phys Chem Earth,Parts A/B/C,29(4/5/6/7/8/9):329-337.
Brace W F,Orange A S.1968.Electrical resistivity changes in saturated rocks during fracture and frictional sliding[J].JGeophys Res,73(4):1433-1445.
Busby J P.2000.The effectiveness of azimuthal apparent-resistivity measurements as a method for determining fracturestrike orientations[J].Geophys Prospect,48(4):677-695.
Du X B,Xue S Z,Hao Z,Zhang S Z.2000.On the relation of moderate-short term anomaly of earth resistivity to earthquake[J].Acta Seismological Sinica,13(4):393-403.
Huang Q H,Lin Y F.2010.Selectivity of seismic electric signal(SES)of the 2000Izu earthquake swarm:A 3DFEMnumerical simulation model[J].Proc Japan Acad:Series B,86(3):257-264.
Lu J,Qian F Y,Zhao Y L.1999.Sensitivity analysis of the Schlumberger monitoring array:Application to changes ofresistivity prior to the 1976earthquake in Tangshan,China[J].Tectonophysics,307(3/4):397-405.
Lu J,Xue S Z,Qian F Y,Zhao Y L,Guan H P,Mao X J,Ruan A G,Yu S R,Xiao W J.2004.Unexpected changesin resistivity monitoring for earthquakes of the Longmen Shan in Sichuan,China,with a fixed Schlumberger soundingarray[J].Phys Earth Planet Inter,145(1/2/3/4):87-97.
Park S K,Johnston M J S,Madden T R,Morgan F D,Morrison H F.1993.Electromagnetic precursors to earthquakesin the ULF band:A review of observations and mechanisms[J].Rev Geophys,31(2):117-132.
Qian F Y,Zhao Y L,Huang Y N.1996.Calculation of the parameters of georesistivity anisotropy and case history ofearthquake precursors[J].Acta Seismologica Sinica,9(4):617-627.
Scholz C H,Sykes L R,Aggarwal Y P.1973.Earthquake prediction:A physical basis[J].Science,181(4102):803-810.
Wang C Y,Goodman R E,Sundaram P N,Morrison H F.1975.Electrical resistivity of granite in frictional sliding:Application to earthquake prediction[J].Geophys Res Lett,2(12):525-528.
Wang C Y,Sundaram P N,Goodman R E.1978.Electrical resistivity changes in rocks during frictional sliding and fracture[J].Pure Appl Geophys,116(4/5):717-731.
Yang C H,Cheng P H,You J I,Tsai L L.2002.Significant resistivity changes in the fault zone associated with the 1999Chi-Chi earthquake,west-central Taiwan[J].Tectonophysics,350(4):299-313.
1据2013年全国电磁会商会相关单位资料报告.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心