Mechanic Behavior of Steel-Concrete Composite Girder of Long-Span Cable-Stayed Bridge

In order to investigate the mechanic behavior of steel-concrete composite girder in long-span cable-stayed bridge, finite element method (FEM) analysis and specimen test of Guanyinyan Yangtze River bridge were carried out. By using FEM program ANSYS, a 3D model for girder section was founded, and elastic analyses of stress distribution of composite girder under different load cases were performed. By considering the nonlinear material properties and nonlinear slip of shear stud, elastic-plastic behaviors of composite girder were analyzed. A test specimen for composite girder with a scale of 1 to 2 was designed, and its static load test was carried out. Stresses at test points in cross section of composite girder bearing different load cases were obtained. The research results show that few relative slippage occurs between steel plate girder and concrete slab of composite girder bearing design load. Shear studs are qualified to resist interface shear and ensure a full composite action. The distribution of stresses in cross sections are similar to the assumption of plane cross-section. For the composite girder, steel girder mainly provides bending strength, while concrete slab provides compression strength mainly.