Simulation of Influencing Factors of Buried Pipeline Interfered by Subway Stray Current

Abstract

The degree of interference of stray currents generated by urban rail transit to nearby buried pipeline was governed by a variety of factors. The buried pipeline model containing the subway return current system was built by COMSOL software, and the fluctuation characteristics of pipeline potential under single and bilateral power supply modes were analyzed to determine the influence of subway return current system parameters and soil resistivity and pipeline corrosion layer resistivity on pipeline potential, while the distribution of pipeline potential under non-uniform soil model was calculated. The results show that when the locomotive traction current and rail longitudinal resistance are doubled, the fluctuation degree of pipeline potential is approximately the same multiple. When the soil resistivity is 1000Ω·m or the pipeline anti-corrosion coating resistivity is 106Ω·m, the pipeline is free from stray current interference. The rail ground transition resistance is not a significant factor of pipeline potential fluctuation. The operation of the train causes the corrosion sate of the pipeline to change constantly. When the longitudinal soil resistivity is unevenly distributed, the increase of soil resistivity at the traction substation side leads to the overall positive shift of pipeline potential and further intensification of pipeline corrosion. The simulation results provide a reference for the railway department and pipeline department in the reasonable planning and layout of rail transit and pipeline.