Comparison of Vibration Characteristics of Floating Slab Track in Rail Transit Viaduct with Time-Domain and Frequency-Domain Models

Floating slab tracks have been widely adopted in rail transit viaducts to reduce the bridge vibration and structure-borne noise. To calculate the vibration of the coupled track-bridge systems, both time-domain and frequency-domain methods can be applied although their relative performance is not very clear. This study aims to compare the two methods and then provide some guidelines in choosing the appropriate method in the vibration prediction. The principle and methodology of the two calculation methods are firstly introduced, and the models for the train, track and bridge are developed using the same parameters. Comparison is made of the vibration of bridge and floating slab obtained from the two methods with different train speeds. It is found that the results from the two methods show good consistency in the frequency region above 20 Hz. It is shown that the results from different loading cases should be averaged with care when the frequency domain method is adopted. When using irregularity measured on site, the simulated vibration of floating slab and bridge from the two methods match well with the experimental results.