Analysis of Metro Stray Current Interference on Underground Pipelines with a SACP System by Field Tests and Numerical Simulation

摘要

In cities, stray current interference on underground pipelines caused by metro systems may be a serious issue due to their construction and limited urban space. The sacrificial anode cathodic protection (SACP) system, usually used as an external corrosion control method for the city gas pipelines because of its convenient management, was considered to be somewhat effective in mitigating the stray current interference. In this work, metro stray current interference on underground pipelines with a SACP system was studied, and factors affecting stray current interference such as sacrificial anodes, isolation joints, coating qualities and soil resistivity were analyzed by field tests and numerical simulation. The results showed that the lower anode-to-earth resistance of sacrificial anodes and grounding systems indicated a greater potential for stray current pickup, and increased interference. The effects of increasing isolation joints and installing switches such as diodes between the anodes and pipelines were also considered, and these results indicated that these methods were able to mitigate interference to a certain extent.