Long-term Behavior Of Concrete-filled Steel Tubular Arch Bridges With Consideration Of Construction Process

In recent years, concrete filled steel tubular arch bridge has been widely used in China due to its high bearing capacity, capability in spanning large distance, conveniency in construction and pleasing aesthetical appearance. Meanwhile, time-effect of core concrete on CFST arch bridge has been causing increasing attention.In this paper ,A finite element model for Dongguan Waterway bridge with the consideration of construction process is built by ABAQUS to investigate the time-effect on the static response of CFST arch bridge under construction during the operation. EC2 model and step-by-step method are introduced into ABAQUS by UMAT to consider time-effect of the core concrete in arches. The reliability of the analysis method and the finite element model is validated by comparing with the measured data. The influence of varying loading ages of the core concrete during the construction is calculated. In the end, time-effect on the stability of parabola arch is investigated with patameters(ie. ratio of rise to span, ratio of slenderness, loading age et al) based on nonlinear constitutive models introduced by UMAT.It is shown that time effect of the core-concrete in arch ribs has a considerable influence on the static response of CFST arch bridge. Time effect will significantly increase the magnitude of the deflection of the arch rib, and the stress in the steel component. The actual loading ages of the core concrete during construction should be considered when calculating the static response of CFST arch bridge. Time-effect on the ultimate capacity of parabolic arch has the largest decrease of 15% with patameters considered in this thesis.