Papers by Keyword: Composite Girder

Abstract: The main bridge of Quanzhou Bay Sea-Crossing Bridge is a composite girder cable-stayed bridge with span arrangement (70+130+400+130+70) m and with double pylongs,separated decks.It’s the first time to using the dry joints assembly in composite girder cable-stayed bridge,the technology of precasting and installing for integral segment is introduced.

Abstract: Corrugated steel webs have crinkled effect without capacity bearing the axial force and bending moment, which leads to its effective elastic modulus is smaller than that of material. This paper deduced the computational formula of effective elastic modulus corrugated steel webs, and puts forward the calculation method for corrugated steel webs of composite beams. Combined with a continuous composite box-girder bridge with corrugated steel webs, the finite element model is built to analyze the bending performance such as normal tensile stress, normal compressive stress and crack resistance.

Abstract: The mechanical behavior of the support regions for continuous composite girders with tensile stresses in the concrete slab and compressive stresses in the lower steel profile becomes strongly nonlinear under negative bending moments. A static test on four half-scale model of a steel and concrete composite girders with different shear connectors including studs and PBL under hogging moments was conducted and observed to evaluate the influence of shear connector on inelastic behavior such as flexural stiffness reduction, crack initiation and development in concrete slab. From the test results, the flexural stiffness and loading capacity of the composite girders were improved by PBL shear connector. Higher initial cracking load and crack resistance stiffness of composite girders with PBL shear connector under serviceability limit state was obtained during crack development process. The test specimen could be assumed as full composite section until the ultimate state from load-slip relationship of shear connector. Analytical and experimental studies can serve as a basis for continuous composite bridges design.

Abstract: The concrete decks in wide box composite girder bridge carrying vehicle load directly are easy to failure. So the decks in approach bridge of Jiubao Bridge are designed to renewable component. Several deck removal plans were put forward based on the structure characteristics of the Jiubao bridge. Spatial finite element model of the bridge was set up and the responses of approach bridge under different removal plan were analyzed. The analysis results show that methods proposed in this paper about deck removal in local position or in whole span are feasible; however different whole span removal method affect the mechanical behavior of the approach bridge heavily.

Abstract: Taking a long-span composite girder cable-stayed bridge with three pylons under construction as the object of research, this paper establishes a three-dimensional finite element model of a bridge considering the geometric nonlinearity, material nonlinearity and interface slip effect in composite girder, and analyzes the failure loads and failure modes of the structure at bearing capacity limited state. The results show that the ultimate load-carrying capacity is high at bearing capacity limited state, load case whose live load acts on one main span is more unfavorable, and according to the structural failure modes, increasing the ability of the middle pylon to resist bending moment can improve the ultimate load-carrying capacity of the whole bridge quickly.

Abstract: Based on tension-compression and bending equivalences, an equivalent single material plate is formed to substitute bridge deck of composite girder with steel fiber reinforced concrete (SFRC) and steel. Thickness and elastic modulus of the equivalent plate are then formulated. After three dimensional finite-element analyses of the bridge deck, in terms of shell element membrane effect and girder flexion-torsion theory, combined with compatibility of deformation, single material shell element stress is restored to stresses on SFRC plate and steel plate separately; shear force distribution on shear keys between SFRC and steel is analyzed.