A New Design Concept for Steel Bridge Decks

This paper proposes an innovation to overcome problems associated with steel orthotropic decks (high cost and poor record of fatigue durability) and transform the design of steel decks. The innovation is based on the use of laser welding to produce an enclosed sandwich panel profile. The sandwich profile overcomes many of the constraints to structural performance associated with the use of conventional orthotropic steel decks. As well as enhancing the global structural characteristics of the deck, fatigue durability is further enhanced by the laser welding process used to fabricate the panels. An extensive range of fatigue tests is presented on the welds used to join the panels. A jointing arrangement is described that offers outstanding fatigue strength and exceptional economy in assembly and fabrication. Laser welds are extremely inexpensive to produce and the use of proprietary rolled sections offers significant savings in construction costs compared to conventional steel deck designs. The sandwich design thus has the potential to provide a competitive, lightweight alternative to the concrete decks used in general bridgework. Further testing of a complete deck assembly is required to exploit the future potential of the system.