The New Storstrøm Bridge – Prestressed Box Girder Design

The New Storstrøm Bridge is a 3.8 km long combined rail and road bridge currently under construction. It will be Denmark’s third longest bridge. It comprises two approach viaducts with 44 spans, typically 80 m long, and a single-tower cable stayed bridge located centrally within the strait crossing, with two 160 m navigational spans. The 25 m wide deck is a prestressed concrete box girder with a unique asymmetric cross section and wide cantilevers. It carries a two-track, high speed railway and a carriageway comprising a two-lane road and a combined pedestrian-cycle. The tight construction schedule imposed to the Design & Build Contract requires the use of full prefabrication of the box girder. A span-by-span construction method based on the erection of typically 73 m-long precast segments is adopted. This paper presents the main challenges of the box girder design due to the construction method, the unusual cross-section and the heavily asymmetric traffic loading.