Local Stress Analysis Of Steel- Concrete Joint Section In The Long-Span Railway Hybrid Girder Cable-Stayed Bridge

The wide application of hybrid girder cable-stayed bridge in recent years forces many engineers to study various structures of steel-concrete joint section of the stiffening girder, which satisfies structural demands on ratio of side to main span. Steel-concrete joint section design is one of the key technologies in hybrid girder. Considering the complexity of structural form and load-transferring mechanism of steel-concrete joint section, engineers who can master its mechanical performance will make significant and practical engineering contributions to structural safety and durability. Taking the Yongjiang Super Large Bridge as the engineering background in this thesis, the finite element simulation analysis method is applied to study the force transfer mechanism and the mechanical performance of the steel-concrete joint section in the hybrid girder cable-stayed bridge, as well as to analyze and compare the structural stress state under different structural parameters. Major contents in this thesis are listed as follows:1. Major research background and professional knowledge of hybrid girder cable-stayed bridge are summarized in this thesis, including its development course, structural characteristics, structural form and stress features of the steel-concrete joint section, research status and basic knowledge of shear connector.2. Software of MIDAS/CIVIL is applied in this thesis to establish the 3D finite element model of the whole bridge, as well as study the whole structure effect of sheer force, bending moment and axial force under the most unfavorable load conditions in control sections of joint section through calculation.3. The large finite element software MIDAS/FEA is adopted to build up the finite element model of steel-concrete joint section, so as to analyze the stress distribution and force transfer mechanism in joint section.4. Influence resulted from parameters variation like the thickness of bearing plate to the mechanical performance of joint section is studied and discussed.