Wind turbulence around a bridge deck in full scale

Abstract

This paper studies the interaction between atmospheric turbulence and a closed-box bridge girder using new data acquired on the Lysefjord Bridge in Norway. Two sonic anemometers installed near the deck edges provided wind turbulence data, which were compared to observations of the incoming flow. The investigation provides insights into the distortion of natural wind both upstream and downstream of the deck, and the vortex-shedding process past the deck’s leeward side. In the near-wake region, the pronounced three-dimensionality of the flow was identified and its correlation with the yaw angle of the incident flow was established. Vertical velocity fluctuations served as an indicator of the vortex shedding process, and Strouhal number estimates were found to exhibit a certain sensitivity to the turbulence intensity in the approaching flow. The results discussed contribute to advancing the understanding of full-scale bridge aerodynamics and provide valuable data for validating and improving wind load models. The findings have implications for the design and safety of long-span bridges exposed to atmospheric turbulence.