Advanced layout of a steel bridge - Ullevaalskrysset footbridge

Abstract

The Ullevaalskrysset Footbridge replaces two temporary and ageing truss girder bridges across a busy road intersection with a single, modern steel structure, shaped to suit the requirements of pedestrians and cyclists. Different layouts and bridge types were examined by EFLA in the conceptual phase, resulting in the client choosing a steel box girder bridge with cantilever ribs stretching out from a continuous spine. The bridge is constructed of four ramps with fairly constant construction height and span lengths. The ramps connect to the main spans of the bridge across the two roads at an intersection. The height of the cross section varies across the main spans. A pair of V-shaped steel columns support the bridge. The four ramps join up in an integration zone with increased width to allow for safe intersection of the flow of cyclists and pedestrians in all four directions. The steel bridge has a total length of 290 m in 18 spans and the total width of the structure is 7,2 m. The longest span is 37,5 m, over the main highway (Ring 3), and 27,5 m, over a side road. Tuned mass dampers are installed in both spans to secure acceptable comfort for pedestrians. Practical aspects of steel as a structural material, are widely integrated in the design, resulting in light structure with seamless flowing aesthetic.