Influence of soil structures on corrosion performance of floating-DC transit systems

The production of stray currents by DC-transit systems leads to the corrosion of nearby buried metallic structures, such as pipelines and cable sheaths. The paper details the corrosion performance of a DC transit system with a floating return rail, for a number of different soil-resistivity structures: uniform, horizontal and vertical-layer models. This builds on previous work carried out in homogenous soils. It is shown that a variation in soil type along the route of a transit system can lead to high local leakage-current densities on buried metallic structures, increasing their vulnerability to corrosion damage.