Simulation of Subway Stray Current Interference and Protection Design for Buried Pipelines

Numerical simulations were performed to investigate stray current interference at newly built subway-pipeline intersection areas. The validity of the control equations and boundary conditions was confirmed by comparing simulation results with experimental data. Using the developed pipeline-track system model, the interference effect of different conduction modes on the pipeline was quantified as follow: track leakage currents, station grounding conduction, depot track conduction under various operational scenarios. Protection measures were then simulated for non-compliant areas. Results demonstrated that pipeline interference intensified with either increased train frequency or reduced main track transition resistance, as well as during station grounding or depot-main line connections. The most severe interference occurred at main track-pipeline intersections.