Development of a Vibration Attenuation Track at Low Frequencies for Urban Rail Transit

Railway-induced vibrations at low frequencies have become an important environmental issue with the rapid development of urban rail transit. In this study, a new vibration attenuation track (VAT) capable of passively mitigating vibrations at low frequencies is developed based on an integrated theoretical and experimental study. The full-scale VAT is built which incorporates a floating slab track (FST) and the attached dynamic vibration absorbers (DVAs) with key parameters determined by the fixed-point theory and modal analysis technique. The vibration attenuation performance of the VAT is investigated under train dynamic loads by establishing a three-dimensional coupled dynamic model of a metro vehicle-VAT-subgrade system, and is further elucidated and validated by carrying out full-scale dynamic tests under different harmonic loadings. Computational and experimental results both show that vibrations of the track are effectively absorbed by the attached DVAs leading to a significant reduction of the subgrade vibrations at the low frequency of 9–16 Hz.