Structural Performance and Strength Prediction of Steel-to-Concrete Box Girder Deck Transition Zone of Hybrid Steel-Concrete Cable-Stayed Bridges

Because a large longitudinal force exists in hybrid girder cable-stayed bridges due to the cable tension, its transfer mechanisms on the steel-concrete combination segment would be an important issue. In this study, experiments and theoretical analysis were conducted to characterize the longitudinal force transfer mechanisms of the steel-concrete combination segment in hybrid girder cable-stayed bridges. Five full-scale local structure specimens were designed and manufactured based on the original design of the steel-to-concrete transition zone according to a completed cable-stayed bridge in China. The specimens were subjected to monotonic loading and tested up to complete failure. The load-slip curves; stress distribution and failure modes, which varied with the thickness of the bearing plate; and the shear connector distribution were obtained. To simulate the test properly, calculation methods for predicting the shear connector capacity and corresponding load-slip curves were proposed based on the analysis and experimental results including headed studs and perfobond strip connectors. Thus, a finite-element model using a nonlinear spring to simulate the shear connectors was proposed and validated by the test. Force transfer mechanisms were analyzed, and load distributing between different components of this composite system were revealed. As a result, the load distributing mode could be used to instruct preliminary engineering design and the modeling method could be used to verify it.