Dynamic Performance of Typical Steel Truss-Railway Bridges under the Action of Moving Trains

The dynamic performance of steel railway bridges attracts intensive attention in engineering applications due to the significance and particularity of moving train actions. The monitoring of railway bridges is therefore increasingly popular because it provides a straightforward approach to help understand the train-induced dynamic responses of bridges. This study uses a set of railway bridges with an efficient structural health monitoring system (SHMS) as an example to investigate the train-induced vibrations. Accordingly, the vertical vibrations of three types of girders are analyzed with the field-measured SHMS data. Treating the bridge as a time-varying system, the modal frequencies of the structures are emphatically investigated with the wavelet-based time-frequency methodology. The transverse displacements of the piers are also presented in a time-frequency perspective to evaluate the working status. The dynamic factor due to moving train actions is analyzed and compared with the suggestions in related codes. In addition, the dynamic performance of the train during movement is also evaluated. It is hoped that the findings can provide some reference for the design and analysis of steel railway bridges.