Conceptual Superstructural Systems for Short-Span Bridges

Development and design of several innovative prefabricated superstructural systems for short span less than 75 ft (23 m) highway bridges, including the current state-of-the-art of construction, have been presented. These include cold-formed steel box girder, composite cold-formed steel box girder, prestressed T-box girder, waffle slab, space truss, and rigid frame (flat arch) systems, etc. A numerical rating scheme has been developed to evaluate the relative superiority of one bridge system over the other, and recommendations have been made accordingly. It is found that a superstructure formed from a stiffened plate supported over steel stringers is superior to several other systems considered herein. Prefabricated cold-formed box girder, prestressed concrete T-box girder, rigid frame (flat arch) bridge, and waffle slab systems are very efficient and economical systems that merit implementation as demonstration projects.