Monitoring DC stray current interference of steel sheet pile structures in railway environment

W.H.A. Peelen, E.A.C. Neeft, G. Leegwater, W. van Kanten-Roos, W.M.G. Courage
TNO Delft, the Netherlands

Steel structures near DC powered railways are expected to be affected by stray current interference. This causes accelerated corrosion rates. Therefore steel is often not used as a building material in these cases, although certain advantages over the alternative material concrete exist. These advantages can include amongst others costs, shorter building time and less nuisance during construction.
In this paper a non-destructive DC stray current monitoring system is described and the measurement results from a large-scale field test are given. The monitoring system consisted of specially developed coupon sensors for sheet pile walls with which stray currents could be measured, and so-called Reference Electrode (RE’s), with which electrical potentials were measured. An advanced cost-effective monitoring system was developed, using a zero resistance current measurement and wireless data transmission. A comparison of the experimental results and literature data about corrosion shows that the additional corrosion by stray current interference was negligible compared to natural corrosion. Although quantified in a rather crude manner, the additional corrosion for the situation at hand turned out to be lower than 0.2 mm over a period of 100 year.

Key words: Stray current, DC, railway's, monitoring, field test