Matthias Landgraf

Effects of under-sleeper-pads on long-term track quality behaviour

Under-sleeper-pads (USP) are elastic elements, which are placed under concrete sleepers. The main task of USP is to decrease track ballast degradation. The aim of the present study is to analyse and compare track quality behaviour of sections with concrete sleepers and concrete sleepers equipped with USP. Around 600 km of track are investigated for the study. The initial quality after track renewal and/or tamping and also the deterioration rate are used for the analysis. Based on these results, it is possible to calculate average tamping intervals for both sleeper types and to make a comparison between them. By this means, the potential is provided for pointing out a reduction in maintenance requirements by using under sleeper pads, which results in a prolongation of service life and a reduction of life cycle costs.