Research On Mechanical Behavior Of Steel-Concrete Joint Section Of Hybrid Girder Cable-Stayed Bridge

Recently, with the extensive use of hybrid girder cable-stayed bridge, the mechanical behavior of steel-concrete joint section of the girder is increasingly investigated. Based on the engineering background of WUSU Bridge and research results at home and abroad, the static mechanical properties and load transfer mechanism of steel-concrete joint section of hybrid girder cable-stayed bridge were investigated by means of the combination of model test and finite element simulation analysis. The stress states of the structure with different parameters were comparatively analyzed to propose basic suggestions for the engineering design. The main contents in this thesis are shown as follows:1. The developing process and structural characteristics of hybrid girder cable-stayed bridge were introduced, and the research status of steel-concrete joint section was illustrated from points of structure form and mechanical behavior.2. Based on the research method of model test carried at home and the characteristic of this structure, a1:3reduced scale model was designed. Also, the design details of the model, the testing scheme and loading program were presented.3. The calculating model of the steel-concrete joint section was established with the large general-purpose software ANSYS. Then, the test results were compared with the finite element calculation results to verify the accuracy of two research methods.4. The mechanical properties and load transfer mechanism of steel-concrete joint section were studied by the combination of model test and finite element analysis. The stress distribution law of the steel-concrete joint section in normal serviceability limit state was analyzed, and the load transfer mechanism was researched by calculating the load bearing share of the components in joint section. To evaluate whether it satisfy the requirements of the specification and to ensure it meet the demand of safety, the stress of the steel-concrete joint section in ultimate limit state was also investigated.5. Through the finite element software, the stress state and the load transfer proportion of each component with different parameters were analyzed to present the variation law of the mechanical behavior to the structure parameter. Finally, the primary suggestions of the optimizing design for the steel-concrete joint section were proposed.