Use of high strength steel in Norwegian floating bridges

The Bergsoysund and Salhus floating bridges are pioneering projects related to the use of high strength steel in large scale bridge building. With high strength steel is meant steel with minimum specified yield strength (Re,^ in the range from 420 to 550 MPa. For The Bergseysund floating bridge a total of 5200 tonnes of steel in quality Re,^ 460 MPa is used for the steel superstructure. The superstructure for the Salhus bridge comprise 3000 tonnes of steel quality Re, 540 MPa. This paper discusses the design advantages gained from using high strength steel. Furthermore requirements to materials and weldments to be specified for high strength steel in structures with stringent safety requirements are addressed. Experiences from the fabrication are summarized and recommendations for future projects are given.