基于弱磁效应的埋地管道腐蚀检测研究

Research on Buried Pipeline Corrosion Detection Based on Weak Magnetic Effect

针对在非开挖条件下,难以快速准确排查埋地长输铁磁管道中严重的局部腐蚀等缺陷的技术难题,对弱磁检测技术进行了在埋地铁磁管道检测中的工程应用验证。弱磁检测技术通过分析所检测埋地铁磁管道正上方的磁感应强度分量梯度值dBx、dBy、dBz的波形曲线特征,可以确定腐蚀缺陷及其位置,并同时对腐蚀缺陷进行评价。通过对西气东输二线61~62号阀室管段进行现场非开挖检测,分析发现2处Ⅰ级、10处Ⅱ级和177处Ⅲ级腐蚀缺陷,分析结果与开挖验证坑所得数据相吻合,证明了弱磁检测技术能够准确检测和评价埋地铁磁管道的管体腐蚀缺陷。

In order to solve the technical problem of quickly and accurately detecting serious local corrosion and other defects in buried long-distance ferromagnetic pipelines under trenchless conditions,the weak magnetic detection technology was applied in the detection of buried metro magnetic pipelines. By analyzing the waveform curve characteristics of gradient value dB_x,dB_y and dB_z of magnetic induction intensity component directly above the magnetic pipeline,the corrosion defect and its location could be determined,and the corrosion defect could be evaluated at the same time. In this paper,on-site trenchless inspection of the 61-62 valve chamber section of the Second West-East Gas Pipeline was carried out. 2 points of Grade 1 corrosion defect,10 points of Grade 2 corrosion defect and 177 points of Grade 3 corrosion defect were found.Results showed that the analysis results were in good agreement with the data obtained from excavation verification pits. It was proved that the weak magnetic detection technology could detect and evaluate the corrosion defects of buried metro magnetic pipelines accurately.