地电阻率交流观测中的电感性耦合效应特征模拟和分析  

Study on inductive coupling effect in AC geoelectrical resistivity observation

作　　者：马小溪 王兰炜[3] 朱涛 张宇[3] 张兴国 MA XiaoXi;WANG LanWei;ZHU Tao;ZHANG Yu;ZHANG XingGuo(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Jilin Earthquake Agency,Changchun 130117,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]吉林省地震局,长春130117 [3]中国地震局地震预测研究所,北京100036

出　　处：《地球物理学报》2023年第1期289-300,共12页Chinese Journal of Geophysics

基　　金：中央级公益性科研院所基本科研业务费专项(CEAIEF20220202);中国大陆综合地球物理场观测仪器研发专项(Y201801)联合资助.

摘　　要：地电阻率交流观测方法能够有效抑制测区杂散电流的干扰,包括地铁、轻轨等城市轨道交通的干扰,但是由供电线路与测量线路间磁场的相互作用所引起的电感性耦合效应会对观测结果产生一定的影响.为研究电感性耦合效应的特征,本文建立了地电阻率交流观测的电感性耦合模型,同时计算了供电线路与测量线路间的互感系数.在此基础上,通过正演模拟分析供电信号频率、地电阻率值、供电线和测量线间距离以及平行长度等参数对电感性耦合效应的影响,并将电感性耦合模型应用于台站实际观测数据的分析中,验证模型的合理性.结果表明,电感性耦合效应随供电信号频率、供电线与测量线平行长度的增大而增大,随供电线与测量线间距离的增大而减小,随地电阻率的变化存在峰值;且模型预测的地电阻率值与台站实际观测值有较好的一致性.本文的研究结果为消除地电阻率交流观测值中的电感性耦合效应提供了理论依据和基本模型,为地电阻率交流观测系统的设计和建设提供参考.The AC(Alternating Current)observation method of geoelectrical resistivity can effectively suppress the interference of stray current in the measurement area,such as the subway,light rail and other urban rail transit interference.The inductive coupling effect is a common problem to be solved in the AC observation method.It is caused by the magnetic field interaction between the current circuit and the potential circuit of the observation system and then affects the accuracy of observation.In order to explore the characteristics of inductive coupling effect,an inductive coupling model for AC geoelectrical resistivity observation is built,and the mutual inductance is calculated.On this basis,the effects of electrical frequency,geoelectrical resistivity,distance between circuits,and the length of the parallel segments of two circuits is discussed.The results show that the inductive coupling effect is positively related to electrical frequency and the length of parallel lines.On the contrary,the inductive coupling effect becomes weak as the distance between circuits increases.Besides,there is a peak of the inductive coupling effect as a function of the geoelectrical resistivity.Furthermore,the predicted and observed value of geoelectrical resistivity are compared to verify the model.The model can be used as a theoretical basic to eliminate the inductive coupling effect in practical observations.The conclusion can provide reference for the design and construction of geoelectrical resistivity AC observation system.

关 键 词：地电阻率 交流观测系统 电感性耦合 台站试验 

分 类 号：P319[天文地球—固体地球物理学]