Topographic effects on the aerodynamic design of the Julsundet Bridge

The design of long-span bridges in complex terrains poses significant challenges, particularly in regions with pronounced topographic variations. This study examines the influence of topography on the wind characteristics and its implications for the aerodynamic design of the Julsundet Bridge, a planned long-span structure in Norway. Experimental data from terrain model wind tunnel tests are analyzed to assess how local topography affects wind speed, turbulence intensity, and directional changes along the bridge axis. Special focus is placed on the variations in angle of attack and velocity distribution induced by the surrounding fjords. Results showing terrain-induced effects on the wind directions, turbulence intensities and mean wind velocities are presented. The results highlight substantial spatial heterogeneity in wind characteristics, which must be considered in the prediction of the buffeting response of the bridge. These findings emphasize the importance of incorporating site-specific topographic effects in the design process to ensure optimal performance and safety of the bridge built in complex terrain.