燃气顶管管道检测方案设计及腐蚀风险评价研究

Inspection Scheme Design and Corrosion Risk Assessment of Gas Pipe-Jacking Pipeline

针对顶管管道腐蚀参数检测装置及测试系统不完善的问题,设计了一套柔性环绕式的管道检测装置,结合配套的地面测试桩,可便捷地测试相关电位及电流,满足了腐蚀风险评价的数据需求。最终建立了基于电流-电位法的防腐层面电阻率计算、基于密间隔电位(CIPS)的防腐层破损点判断、基于电流趋势的牺牲阳极性能诊断、基于试片电流密度的腐蚀速率预测等方案,进而制定了防腐层面电阻率、破损点、牺牲阳极性能、阴极保护效果、腐蚀速率等单项风险评价方法,构建了顶管管道局部监测点及整体管段的腐蚀风险综合评价体系,对于管道的腐蚀风险的预防性管理有一定指导意义。

In view of the imperfection of the pipe-jacking pipeline corrosion parameter detection device and testing system, a set of flexible surrounding pipeline detection device was designed. With the support of ground test pile, this device could measure relevant potential and current easily, meeting the data requirements of corrosion risk assessment. Finally, the resistivity calculation of the anti-corrosion layer based on the current potential method, the judgment of the damage point of the anti-corrosion layer based on the close interval potential(CIPS), the diagnosis of the sacrificial anode performance based on the current trend, and the prediction of the corrosion rate based on the current density of the test piece were established. Furthermore, the single risk assessment methods regarding the electrical resistivity of the anti-corrosion layer, the damage point, the sacrificial anode performance, the cathodic protection effect and the corrosion rate were formulated. The comprehensive evaluation system of corrosion risk of the local monitoring points and the whole pipe section was established, which would have great guiding significance for the preventive management of the pipeline.