The Hardanger Bridge monitoring project: Long-term monitoring results and implications on bridge design

In design of slender suspension bridges, which are prone to wind excitation, accurate prediction of dynamic response is essential for reliable designs. However, dynamic response calculations involve many sources of uncertainty, one of which is the modeling of the gust loading. The long-term data of wind velocities and accelerations from the Hardanger Bridge monitoring project are presented here to investigate the variability in dynamic response. The buffeting response of the bridge is then evaluated in frequency domain using a multimode approach. The self-excited forces are modeled using aerodynamic derivatives obtained from free vibration tests. The modal properties of the bridge are extracted from a finite element model. The spectral densities and coherences required to describe the gust loading are modeled using design provisions. The analytical results are compared with the full-scale measurement results and the implications on design of long-span suspension bridges are discussed.