Yura, J. A.Frank, Karl H.559911192008-08-282008-08-282002http://hdl.handle.net/2152/494textTrapezoidal steel box girders are becoming increasingly popular as a bridge system due to their torsional efficiency and aesthetic appearance. These bridge systems utilize one or more trapezoidal steel girders with a cast-in-place composite concrete roadway. The critical design stage occurs during pouring of the bridge deck, when the steel superstructure must support the weight of the fresh concrete. Top-lateral bracing systems are used to provide both strength and stiffness during construction. A method for the design of top-lateral bracing systems was developed through field and laboratory experiments conducted on full-scale trapezoidal steel box-girders. The top-lateral bracing systems investigated included traditional single-diagonal truss systems and stay-in-place metal deck forms used during deck casting. Results include torsional girder stiffnesses, brace forces, and loaddeflection responses. Design issues, limitations, and guidelines for truss, metaldeck, and combined top-lateral systems are presented.electronicengCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.Bridges, Box girder--Design and constructionBridges, Iron and steel--Design and constructionThesis3108484