特深地下管线的电磁场特征分析及探测研究

研究了管线的一系列电磁场特征，介绍了特深管线探测应用状况，通过实例分析了从1 m到21 m了不同埋深直线电流及强电流3~21 m情况下的电磁场Hx、Hz、ΔHx 〖WTBZ〗的归一化异常的分布特征 , 提出了对特深管线探测的对策，即频率、电流、远端接地等提高信噪比的技术对策，提出了确定地下金属管线平面位置、埋深的方法，利用水平磁场分量70%法确定管线深度的适用条件，分析了特深管线探测的干扰因素，广州市3个特深管线的探测成功实例，说明了方法的良好效果.

Study on electromagnetic field feature and probing effect about very deep buried pipeline

This paper describes the study on a set of profile curves of the electromagnetic field and the detecting effect about deep buried pipeline. This paper begins with the introduction about the development state to detecting particular deep pipeline. Then maps show all the Hx , Hz and ΔHx  curves and their normalized Hx and ΔHx curves of electromagnetic field about linear electric current on different depth from 1 to 21 meters, maps also show the Hx, Hz curves of electromagnetic field about linear electric current on different depth from 3 to 21 meters. Next, this paper proposes some locating technologic measures on raising signal-to-noise ratio such as direct connection, frequency, electric current and far grounding and so on for improve the locate precision of the deep underground pipeline. It also put forwards the method to conform its location and depth, analysis the applicable conditions about using Hx 70% method for the determination of the depth to the underground pipeline, and studies the interferential factor on deep pipeline location. Finally, it provide three detecting examples to deep pipeline with its depth is deeper than 5m in Guangzhou city.