Evaluation on Vibration Serviceability of a Cable-stayed Footbridge through Field Measurement

Many footbridges may suffer from the intensive vibration induced by human activities. To be a direct and effective approach,field measurement is widely utilized to assess the vibration serviceability of footbridge. Several typical footbridges with different structural configuration are taken as real examples to investigate the pedestrian-induced vibration through field measurement. The dynamic responses of the example footbridge under ambient excitations are collected through field measurement to identify the natural frequencies and mode shape of the footbridge by using Natural Excitation Technique(NexT) and Eigensystem Realization Algorithm(ERA). The vibration serviceability of the footbridge is evaluated based on dynamic responses made from field measurement in line with the specifications such as ISO 10137 and BS5400. The analytical results in this study can be taken as the references for the assessment of the pedestrian-induced vibration and dynamic serviceability of footbridges.