The effect of modal parameter uncertainties on the vibration serviceability assessment of footbridges

Due to the trend towards greater slenderness supported by the increasing strength of materials, modern footbridges are very often lively structures prone to human induced vibrations. Current codes of practice provide methodologies to assess the dynamic behaviour during the design phase. The reliability of this vibration serviceability check strongly depends on the predicted dynamic behaviour of the footbridge, characterized by the modal parameters. This paper studies the effect of the modal parameter uncertainties on the vibration serviceability assessment of three footbridges.