Receptance Test Performed on a Laboratory Ballasted Track Section

A receptance test was performed in a ballasted track section with three sleepers after cyclic loading tests. This physical model is installed in the laboratory of Heriot-Watt University. The ballasted track is resting on a compacted substructure that is characterized by a frost protection layer (FPL), subgrade and geosynthetic-reinforced soils (GRS). A geogrid TX190L was placed between the ballast and FPL. The ballasted track is characterized by BS113A continuous rails, elastic pads and three G44 sleepers (spaced 0.65 m) embedded on the ballast layer. The receptance test is a helpful tool in the identification of the resonant frequencies that characterize the dynamic behavior of the track, and the results can be used in a calibration process of a numerical model. The response of the track was evaluated through the accelerometers placed on the head and web of the two rails and on the sleepers. The experimental tests were performed over the three sleepers, and the obtained results were compared taking into account the coherence function. Furthermore, the identification of the main resonant frequencies (full-track resonant frequency, anti-resonant frequency of the sleepers and rail resonant frequency) was also analyzed considering the accuracy of the obtained results in terms of coherence (only values higher than 0.9 were considered).