Automated Design of Prestressed Concrete Box Girders (194-1F)

Three computer programs have been developed or adapted to assist in the design of multi-beam prestressed concrete box girder bridges. Programs DBOXSS and DBOXDS treat girders with straight and draped strands, respectively. Each program has a "design" option which selects concrete release strength and strand pattern for a specified cross section and 28-day concrete strength to minimize the total number of strands used. The programs also contain an "optimization" option which determines release and 28-day concrete strengths and strand pattern that minimize the total cost of the girder, An analysis program AMBB has also been developed to compute lateral load distribution factors for the members of a multi-beam bridge. Specifications governing the designs produced are from the American Association of State Highway and Transportation Officials, 1973 Bridge Specification and 1974 and 1975 Interim Specification.