井下地电阻率观测影响系数分析——以江宁地震台为例
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摘要
采用水平层状均匀介质中点电源位于任意深度时的电位解析表达式,以江宁台3层电性结构为例,分析了井下对称四极地电阻率观测时各层影响系数随深度、极距的变化,并结合探测深度探讨了实施井下观测时影响系数在选择供电极距和电极埋深时的作用。结果表明,对于"K"型电性结构,江宁台井下观测对地表、浅层干扰有较强的抑制作用,其短极距观测对地表、浅层干扰的抑制能力显著优于长极距观测;长极距观测在电极埋深H小于100m时对地表介质季节性的干扰具有放大作用;浅层影响系数一定时,电极埋深和供电极距需同时增加;江宁台井下观测供电极距AB/2取100～150m、电极埋深H为250m较为合理。
With the analytical expression of the potential of a point-level power supply with a horizontal layered uniform medium at an arbitrary depth,we take the three-layer electrical structure of the Jiangning seismic station as an example,analyze the variation of the influence coefficient of each layer with depth and pole distance when the symmetrical quadrupole resistivity is observed,and combined with the depth of detection,explore the distributions of influence coefficients with the spacing and depth of electrodes when the Schlumberger arrays are used in the resistivity observation. The results show that the deep-well observation of the Jiangning seismic station has good inhibition to surface and shallow interference. The short-range observation has a significantly better ability to suppress shallow surface disturbance than the long-range observation. Disturbances from surface might be amplified when the deep-well observation is within 100 m for the K-type electrical structure. For the fixed sensitivity coefficient,the electrode burial depth increases with the current electrode length. The annual variation features are analyzed by calculating the influence coefficient of each layer. It is reasonable to take 100 ～ 150 m from the electrode length and 250 m from the electrode buried depth. The calculated results could be used as reference for the selection of electrode buried depth and current electrode length when deep-well observation would be used in similar stations.
With the analytical expression of the potential of a point-level power supply with a horizontal layered uniform medium at an arbitrary depth,we take the three-layer electrical structure of the Jiangning seismic station as an example,analyze the variation of the influence coefficient of each layer with depth and pole distance when the symmetrical quadrupole resistivity is observed,and combined with the depth of detection,explore the distributions of influence coefficients with the spacing and depth of electrodes when the Schlumberger arrays are used in the resistivity observation. The results show that the deep-well observation of the Jiangning seismic station has good inhibition to surface and shallow interference. The short-range observation has a significantly better ability to suppress shallow surface disturbance than the long-range observation. Disturbances from surface might be amplified when the deep-well observation is within 100 m for the K-type electrical structure. For the fixed sensitivity coefficient,the electrode burial depth increases with the current electrode length. The annual variation features are analyzed by calculating the influence coefficient of each layer. It is reasonable to take 100 ～ 150 m from the electrode length and 250 m from the electrode buried depth. The calculated results could be used as reference for the selection of electrode buried depth and current electrode length when deep-well observation would be used in similar stations.
引文
樊晓春、吴帆、袁慎杰,2018a,江宁台地电阻率数据干扰分析,内陆地震,32(2),163~171.
樊晓春、吴帆、袁慎杰,2018b,江宁地电台深井地电阻率观测系统分析,地震地磁观测与研究,39(3),102~106.
解滔、杜学彬、陈军营等,2012a,井下地电阻率观测中地表电流干扰影响计算,地球物理学进展,27(1),112~121.
解滔、杜学彬、卢军,2016,井下视电阻率观测影响系数分析,中国地震,32(1),40~53.
解滔、杜学彬、郑国磊等,2012b,水平两层均匀介质中井下电阻率观测信噪比的理论计算,西北地震学报,34(1),18~22、104.
解滔、李飞、沈红会等,2013,新沂地震台地电阻率反向年变分析,地震学报,35(6),856~864.
解滔、卢军,2015,地电阻率三维影响系数及其应用,地震地质,37(4),1125~1135.
解滔、王洪岐、刘立波等,2014,四平台地电阻率相反年变有限元数值分析,地球物理学进展,29(2),588~594.
康云生、安海静、马可兴等,2013,天水地电阻率地表与井下多种观测方式的实验分析,地震工程学报,35(1),190~195.
刘君、杜学彬、陈军营等,2015,地表与井下地电阻率观测数据分析,地震,35(1),112~122.
毛先进、杨玲英、钱家栋,2014,水平层状介质中深埋装置系统地电阻率影响系数特征研究,地震学报,36(4),678~685.
毛先进、杨玲英、赵晋民等,2017,井下地电阻率观测的探测深度初步研究,地震学报,39(2),230~238.
聂永安、巴振宁、聂瑶,2010,深埋电极的地电阻率观测研究,地震学报,32(1),33~40.
聂永安、姚兰予,2009,成层半空间深埋电极产生的电位分布,中国地震,25(3),246~255.
钱复业、卢振业、丁鉴海等,1998,电磁学分析预报方法,北京:地震出版社.
钱家栋、马钦忠、李劭秾,2013,汶川MS8.0地震前成都台NE测线地电阻率异常的进一步研究,地震学报,35(1),4~17.
钱家栋、陈有发、金安忠,1985,地电阻率法在地震预报中的应用,北京:地震出版社.
沈红会、李鸿宇、袁慎杰等,2014,江宁台地电场地地铁干扰实验结果分析,地震,34(3),125~131.
沈红会、王丽、王维等,2017,地电阻率长趋势变化及其预测意义,地震学报,39(4),495~505.
王兰炜、张世中、张宇等,2014,井下地电阻率观测中装置系数的计算---以天水地震台井下观测为例,工程地球物理学报,11(1),50~59.
王兰炜、张宇、张世中等,2015,我国井下地电阻率观测技术现状分析,地震地磁观测与研究,36(2),95~102.
王同利、李妍、武晓东等,2017,延庆台地电阻率铁质干扰的有限元模拟,地震学报,39(4),520~530.
许忠祥、安张辉、于华等,2014,海安台井下与地表地电观测对比实验研究,地球物理学进展,29(4),1588~1596.
杨兴悦、杨立明、康云生等,2012,天水地震台井下地电观测系统介绍及其分析,地震研究,35(1),92~97.
姚文斌,1989,电测深数值计算和解释入门,北京:地震出版社.
张世中、石航、王兰炜,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,地震学报,35(1),117~124.
张宇、张兴国、王兰炜等,2016,新型地电阻率交流观测系统研究及江宁台观测实验,地震学报,38(5),807~810.
赵斐、叶青、解滔等,2018,平凉台井下地电阻率观测影响系数分析,中国地震,34(1),104~111.
(1)王兰炜等,2017,井下地电阻率观测技术指导意见
樊晓春、吴帆、袁慎杰,2018b,江宁地电台深井地电阻率观测系统分析,地震地磁观测与研究,39(3),102~106.
解滔、杜学彬、陈军营等,2012a,井下地电阻率观测中地表电流干扰影响计算,地球物理学进展,27(1),112~121.
解滔、杜学彬、卢军,2016,井下视电阻率观测影响系数分析,中国地震,32(1),40~53.
解滔、杜学彬、郑国磊等,2012b,水平两层均匀介质中井下电阻率观测信噪比的理论计算,西北地震学报,34(1),18~22、104.
解滔、李飞、沈红会等,2013,新沂地震台地电阻率反向年变分析,地震学报,35(6),856~864.
解滔、卢军,2015,地电阻率三维影响系数及其应用,地震地质,37(4),1125~1135.
解滔、王洪岐、刘立波等,2014,四平台地电阻率相反年变有限元数值分析,地球物理学进展,29(2),588~594.
康云生、安海静、马可兴等,2013,天水地电阻率地表与井下多种观测方式的实验分析,地震工程学报,35(1),190~195.
刘君、杜学彬、陈军营等,2015,地表与井下地电阻率观测数据分析,地震,35(1),112~122.
毛先进、杨玲英、钱家栋,2014,水平层状介质中深埋装置系统地电阻率影响系数特征研究,地震学报,36(4),678~685.
毛先进、杨玲英、赵晋民等,2017,井下地电阻率观测的探测深度初步研究,地震学报,39(2),230~238.
聂永安、巴振宁、聂瑶,2010,深埋电极的地电阻率观测研究,地震学报,32(1),33~40.
聂永安、姚兰予,2009,成层半空间深埋电极产生的电位分布,中国地震,25(3),246~255.
钱复业、卢振业、丁鉴海等,1998,电磁学分析预报方法,北京:地震出版社.
钱家栋、马钦忠、李劭秾,2013,汶川MS8.0地震前成都台NE测线地电阻率异常的进一步研究,地震学报,35(1),4~17.
钱家栋、陈有发、金安忠,1985,地电阻率法在地震预报中的应用,北京:地震出版社.
沈红会、李鸿宇、袁慎杰等,2014,江宁台地电场地地铁干扰实验结果分析,地震,34(3),125~131.
沈红会、王丽、王维等,2017,地电阻率长趋势变化及其预测意义,地震学报,39(4),495~505.
王兰炜、张世中、张宇等,2014,井下地电阻率观测中装置系数的计算---以天水地震台井下观测为例,工程地球物理学报,11(1),50~59.
王兰炜、张宇、张世中等,2015,我国井下地电阻率观测技术现状分析,地震地磁观测与研究,36(2),95~102.
王同利、李妍、武晓东等,2017,延庆台地电阻率铁质干扰的有限元模拟,地震学报,39(4),520~530.
许忠祥、安张辉、于华等,2014,海安台井下与地表地电观测对比实验研究,地球物理学进展,29(4),1588~1596.
杨兴悦、杨立明、康云生等,2012,天水地震台井下地电观测系统介绍及其分析,地震研究,35(1),92~97.
姚文斌,1989,电测深数值计算和解释入门,北京:地震出版社.
张世中、石航、王兰炜,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,地震学报,35(1),117~124.
张宇、张兴国、王兰炜等,2016,新型地电阻率交流观测系统研究及江宁台观测实验,地震学报,38(5),807~810.
赵斐、叶青、解滔等,2018,平凉台井下地电阻率观测影响系数分析,中国地震,34(1),104~111.
(1)王兰炜等,2017,井下地电阻率观测技术指导意见