الفهرس 
BEHAVIOR OF BOX GIRDER DUE TO TORSIONAL LOADINGOnly 14 pages are availabe for public view
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Abstract
Composite trapezoidal steel box girders are becoming increasingly popular as a bridge system due to their torsional efficiency and aesthetic appearance. The critical design stage occurs during construction and pouring of the bridge deck slab as the steel tub girders with top lateral bracing systems are expected to support the weight of the fresh concrete and other construction loads. Current design guides provide little or no guidance for the design of top lateral bracing systems, which has led to either overly conservative or, in some instances, inadequate bracing designs. Since the top lateral system serves no function after hardening of the concrete bridge deck, perhaps the floor steel decking used for the concrete deck could also function as the top lateral system. The objective of this research is to study the effect of using the floor steel decking to be used as an alternative bracing system during the construction phase. Also, three different systems of top flange bracing are used for the trapezoidal steel box girders. Comparisons are carried out between steel deck forms and different bracing systems to evaluate the viability of using steel deck forms alone during construction stage. The analytical investigation utilizes nonlinear finite element modelling techniques using ANSYS program, considering both geometric and material nonlinearity. The results show that the floor steel decking is advantageous than top bracing system related to the different deformations of the open cross section of the trapezoidal box girder during construction.