Design of a Cable‐Stayed Steel Composite Bridge

Abstract

The design and proposed construction method for the cable‐stayed steel alternate of the Sunshine Skyway Bridge across Tampa Bay, FL, is outlined in detail. For this alternate, the concept of a relatively new steel composite girder was used. The girder comprises a grid of welded steel plate girders and is topped by a concrete deck from precast slabs. The concrete towers with diamond‐shaped box girder legs are connected to the girder by parallel wire or strand cables. The aerodynamic stability of the girder is greatly enhanced by the cables converging from the ouside of the girder to the tower tops, thus creating a stiff space truss. Although this design lost to the concrete alternate by the small margin of 4%, the concept has gained widespread acceptance. In subsequent competitive biddings, cable‐stayed composite bridges proved to be considerably more economical than concrete or all‐steel options. In the future development of cable‐stayed bridges, designs with composite girders, concrete towers, and parall...