Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Conference Object Citation - Scopus: 1Strength Requirements of Permanent Metal Deck Forms Used for Lateral Bracing of Steel Bridge Girders(2006) Eğilmez, Oğuz Özgür; Helwig, T.A.; Herman, R.S.Permanent metal deck forms (PMDF) are often used in steel bridges to support the weight of the wet concrete during deck construction. Although the PMDF also has the potential to provide bracing to steel bridge girders during construction, the stiffness of the PMDF system as a lateral brace is drastically reduced by the eccentric support angle connection detail used to attach the forms to the girders. Laboratory tests have shown that a simple modification to the connection detail can substantially increase the stiffness of these PMDF systems and allow utilization of the PMDF for girder bracing. This paper presents results from a parametrical study conducted to determine stability and strength requirements for PMDF used to provide lateral bracing to steel bridge girders. Detailed FEA models were used to determine the stability bracing strength requirements for the fasteners that are used to connect the PMDF along the sidelaps of the sheets and to the girders. Design expressions are presented as well as an example demonstrating the use of the design equations.Article Citation - WoS: 10Citation - Scopus: 13Buckling Behavior of Steel Bridge I-Girders Braced by Permanent Metal Deck Forms(American Society of Civil Engineers (ASCE), 2012) Eğilmez, Oğuz Özgür; Helwig, Todd A.; Herman, ReaganPermanent metal deck forms (PMDFs) are often used in the bridge industry to support wet concrete and other loads during construction. Although metal formwork in the building industry is routinely relied on for stability bracing, the forms are not permitted for bracing in the bridge industry, despite the large in-plane stiffness. The forms in bridge applications are typically supported on cold-formed angles, which allow the contractor to adjust the form elevation to account for changes in flange thickness and differential camber between adjacent girders. Although the support angles are beneficial toward the constructability of the bridge, they lead to eccentric connections that substantially reduce the in-plane stiffness of the PMDF systems, which is one of the reasons the forms are not relied on for bracing in bridge applications. This paper documents the results of an investigation focused on improving the bracing potential of bridge deck forms. Modifications to the connection details were developed to improve the stiffness and strength of the forming system. Research included buckling tests on a 15-m (50-ft) long, twin-girder system with PMDFs for bracing. In addition, twin-girder tests were also used to validate computer models of the bracing systems that were used for parametric finite-element analytical studies. The buckling test results demonstrated that modified connection details make PMDF systems a viable bracing alternative in steel bridges, which can significantly reduce the number of cross-frames or diaphragms required for stability bracing of steel bridge I-girders during construction.