ABSTRACT
Buffeting-induced vibration of long-span cable-supported bridges is critical for the serviceability and fatigue performance of these structures. Such problems are more prevalent in long-span bridges located in complex terrain and subjected to gusty wind. One of the long-term adverse effects includes the cyclic loading induced by the buffeting which may cause fatigue of the material. As a case study for this work, fatigue life due to buffeting-induced vibrations has been estimated for the longest-span suspension bridge in Norway, the Hardanger Bridge. This bridge is situated in the Norwegian fjords, characterized by consistent and strong winds. The terrain-induced variability in the turbulence field is considered by modelling the field as a joint probabilistic model of turbulence parameters. Utilizing a Finite Element model of the bridge, the modal parameters of the bridge are extracted. Subsequently, the classical multi-modal buffeting analysis is performed to obtain the stress spectra of the hotspots along the bridge girder. Considering uncertain mean wind velocity and turbulence parameters, fatigue damage is calculated using a Bayesian updating approach, where new simulation points were sequentially added to the training data set. Consequently, the fatigue life of the bridge girder is obtained by numerical integration.
