Analysis of the insulation resistances of a high-speed rail transit system viaduct for the assessment of stray current interference. Part 1: Measurement

An investigation into the insulation resistances of the concrete structures of a high-speed rail transit system viaduct is presented in this paper. Measurements of the insulation resistances in three sections of different characteristics are carried out during the construction stages of the viaduct, in order to get insights into the relation between insulation resistance changes and viaduct completion. The measure- ment campaign consists of six sessions of measurement in a period of two and a half years. The measured insulation resistances between a span and its supporting piers and between two adjacent spans show a variation in time and among the viaduct sections. The dispersion of the measurements in the three viaduct sections is highly reduced in the last session of measurements, showing that the insulation resis- tances are related to the progress in viaduct completion and the characteristics of viaduct sections. The main requirements for protective provisions for both low- and high-speed lines are also detailed.