Research On Electromagnetic Detection Of Underground Pipelines

Underground pipe network detection provides important basic information for urban planning,reconstruction,construction and development.Traditional electromagnetic detection methods are limited by environmental conditions,and the measurement accuracy is difficult to guarantee.GPR based on wideband electromagnetic pulse detection can not only effectively detect metal pipelines but also plastic pipelines which are unable to be detected by general electromagnetic method,and has the characteristics of strong applicability,fast and high resolution.However,for underground multi-pipeline detection in some geological environments,radar image data is difficult to interpret and the accuracy of pipe diameter identification is low.Therefore,this paper takes electromagnetic detection of underground pipeline as the subject to carry out research,and provides reference for the application of electromagnetic detection of underground pipeline engineering.This paper studies from the following aspects:(1)The principle and method of detecting underground pipelines by potential method,potential gradient method and electrical profile method of apparent resistivity in direct current detection are analyzed.The electromagnetic principle of detecting underground iron pipe by magnetic method and the detection method of underground pipeline based on vertical magnetic field and its gradient are analyzed.The principle and method of detecting buried pipeline by electromagnetic induction are discussed,including secondary field anomaly method,mutual inductance coefficient method and tracer method.(2)The principle of GPR detection and the formation method of B-Scan profile are analyzed.The hyperbolic features of radar images of underground pipelines are analyzed through measured data,simulation experiments and modeling,providing a basis for the interpretation of GPR image data.(3)The principle and method of clutter suppression and image enhancement preprocessing of ground penetrating radar signal are analyzed and discussed.The extraction method of characteristic hyperbola of underground pipeline is studied,and the hyperbola fitting and parameter extraction of radar profile of underground pipeline are realized.