Research On Composite Effect Of Steel-Concrete Composite Beam Of Long-Span Cable-Stayed Bridge

Steel-concrete composite girder is a newly structural type which is developed based on the foundation of steel structure and concrete structure. Composite girder has been widely used in bridge engineering because it has many advantages such as lighter weight, construction convenience, light graceful shape, long span capacity and so on.Based on the background of ChongQing GuanYinyan bridge, by the use of spatial finite element method, the mechanical behaviors of steel-concrete composite beam and effective width of concrete slab under axial force and bending moment are studied. In the meantime, the distribution of internal forces between concrete slab and steel girder is acquired.The thesis simply reviewed the research actualities of steel-concrete composite girder in our country and the general calculation principle of composite girder. An integral finite element model of GuanYinyan bridge is established in Doctor Bridge V3.0 software to calculate the internal forces of all members under various load conditions. Based on the calculation result, the spatial finite element model of the segment near the tower and in the middle of the main span is established to study the distribution of internal forces between concrete slab and steel girder, the distribution of stress and effective flange width evaluation of concrete slab. The main factors that affect the distribution of longitudinal stress are discussed.Hope that the conclusions in this thesis can provide some reference for composite girder cable-stayed bridge design and construction.