用自然电位估算地铁干扰大小——以天津塘沽地震台为例  

Estimating the magnitude of subway interference using spontaneous potential—Taking Tianjin Tanggu Seismic Station as an example

作　　者：刘建波[1] 雷生学[1] 张明东[1] 刘文兵[1] 刘金城[1] 马义山[1] LIU Jianbo;LEI Shengxue;ZHANG Mingdong;LIU Wenbing;LIU Jincheng;MA Yishan(Tianjin Earthquake Agency,Tianjin 300201,China)

机构地区：[1]天津市地震局,中国天津300201

出　　处：《地震地磁观测与研究》2023年第5期107-117,共11页Seismological and Geomagnetic Observation and Research

基　　金：天津市地震局科研项目(项目编号:Yb202301);“天津及周边地区地震风险预测技术研究”科技创新团队项目。

摘　　要：地铁杂散电流会导致地表电位发生变化并引发危害,其大小与轨道绝缘情况、车辆行驶速度等因素有关,难以直接测量。基于自然电位不仅是地下介质电导率分布的响应也是场源(电流源)反应的特性,利用“轨道—大地”模型,计算最近地面线路单列列车行经塘沽地震台时产生的杂散电流最大可达50 A。结合地铁“日行夜停”的特点,对塘沽地震台自然电位数据进行分段研究,估算出地铁杂散电流平均约33.15,引起的电位变化平均约为0.68,并得到地铁运行最大日干扰时间规律。为准确评估地铁运行对地电观测的影响,提出科学改造方案提供了理论依据。Metro stray currents can cause changes in surface potential and cause harm.Its magnitude is related to factors such as track insulation and vehicle speed,making it difficult to directly measure.Based on the characteristics that natural potential is not only a response to the conductivity distribution of underground media but also a response to field sources(current sources),the“track earth”model is used to calculate the maximum stray current generated by a single train passing through the Tanggu Seismic Station on the nearest ground line,which can reach 50 A.Based on the characteristics of the subway’s“daily operation and night stop”,a segmented study was conducted on the natural potential data of Tanggu Seismic Station.It was estimated that the average stray current of the subway is about 33.15 A,and the average potential change caused is about 0.68 mV.The maximum daily interference time pattern of subway operation was also obtained.To accurately evaluate the impact of subway operation on geoelectric observation,a scientific transformation plan is proposed to provide a theoretical basis.

关 键 词：自然电位 地铁杂散电流 电位变化 

分 类 号：P315.722[天文地球—地震学]