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原文传递 Applications of Partial Depth Precast Concrete Deck Panels on Horizontally Curved Steel and Concrete Bridges.

题名：	Applications of Partial Depth Precast Concrete Deck Panels on Horizontally Curved Steel and Concrete Bridges.
作者：	Roskos, C.; Biju-Duval, P.; Kintz, J.; McCammon, V.; Wang, Y.; Donahue, S.; Helwig, T.; Engelhardt, M.; Bayrak, O.; Clayton, P.; Williamson, E.
关键词：	Curved girders, Partial depth precast concrete panels, Steel I-girders, Steel tub girders, Concrete U-beams
摘要：	Horizontally curved bridges are commonly used for direct connectors at highway intersections as well as other applications. The majority of curved bridges utilize continuous steel curved I-girder or tub girder systems. In recent years, isolated applications of spliced prestressed concrete U-beams have been successfully used for curved bridge applications in Colorado and are currently being considered for use in Texas bridges. One of the most critical construction stages from a stability perspective is placement of the wet concrete deck at which point the girders must support the full construction load of the system until the deck stiffens and acts compositely. Bridges with a curved geometry experience significant torsional forces and require a substantial amount of bracing to control deformation during construction. Bracing in the form of cross frames for steel I-girder systems, top lateral trusses for steel tub girder systems, and lid slabs for concrete U-beams are provided to improve the girder behavior. While partial depth precast concrete panels (PCPs) are commonly used as stay-in-place formwork for straight bridges, the panels are not currently permitted on horizontally curved girder systems in Texas. TxDOT would like to extend the use of PCPs to bridges with curved girders. This report focuses on the stability of PCPs that rest on polystyrene bedding strips. The project studied the behavior for PCPs with and without a positive connection to steel girders and also considered the behavior of the current TxDOT reinforcing details for PCPs with concrete U-beam systems. The experimental portion of this study consists of large-scale PCP shear tests and large-scale combined bending and torsion tests on both a twin steel I-girder system and on a single steel tub girder. The PCP shear tests were used to develop a simple and effective connection between the PCPs and the girder, as well as to empirically determine the in-plane stiffness and strength of the PCP/connection system. The large-scale girder tests were used to investigate the performance of PCPs and their connection to a system that simulates the load experienced in a realistic construction situation. Also, parametric finite element modeling of the PCPs and the curved girder systems were performed and validated with the results from the experimental tests. The finite element models were used to develop an understanding of the fundamental behavior of the steel girder systems in combination with the PCP systems. In addition to focusing on connection methods to the PCPs, guidelines were also developed for cases where the panels can be used on horizontally curved girder systems without a positive connection to the girders.
报告类型：	科技报告