Proposed Design Specifications for Steel Box Girder Bridges

摘要

Specification for design, of steel box girder bridges are proposed for the AASHTO Specification for Highway Bridges. Load Factor Design approach is used. In the design of compression flanges residual stresses and geometric imperfections are considered. For unstiffened flanges a new strength curve is proposed. Strength of stiffened flanges is given as a function of geometric parameters by interaction diagram based on second order analysis. Strength of webs is obtained as a sum of elastic buckling strength, and a lower limit of tension field strength. Web stiffeners are proportioned by strength and rigidity criteria to remain straight up to ultimate web capacity. Also given are rules for design of tension flanges, diaphragms, cross frames and other members, recommended fabrication tolerances and erection provisions. Discussion of principal problems, review of current U.S. and European specifications and commentary are included. Appendix A contains bibliography; Appendix B contains review of design codes.