Research On The Steel-concrete Joint Section Of Steel-concrete Hybrid Girder Bridge

Steel-concrete hybrid girder bridge in the long-span bridge is better in safety and economics than other kinds of girders.The stiffness mutation position,force transmission mechanism and the structure of Steel-concrete joint section is complex which lead to the stress concentration problem.It has received widespread attention.Based on the Chongqing Yongchuan Yangtze River Bridge project,specifically research for the joint section is carried systematically through experiment and finite element analysis.The purpose of this paper is to study the steel combined section of Yongchuan Yangtze River Bridge's actual performance.Experiments can help understand the deformation and mechanical properties of the real structure.The force transmission mode,stress and strain distribution and so on are as the basis of numerical calculation and analysis and inspection standards.In addition,the segmental model manufacture and forming process of the specimens can simulate the actual original bridge construction process.Through the actual loading,the stress and strain distribution of the joint and the adjacent beam section under the design load and 1.7 times the design load are tested,and it is evaluated that bridge can keep safe and reliable.At the same time,the paper puts forward the theoretical results through the finite element analysis.Combining the engineering practice and model test research,the finite element model refinement is established to find a real and effective finite element.Then according to the local scale model test and finite element model results,the stress transfer path and dispersion under the test condition is analyzed.And reasonable theoretical explanation is given.In this paper,a finite element model of the scaling method is proposed and it is compared with the experimental results.In addition,this paper established a full scale finite element model of the whole bridge,to compare with the scaled finite element model and analyze the effects of scale.The scaled model can well simulate the stress distribution of the actual structure and size.And through the detailed finite element analysis of the full-scale model,it is proved that the real bridge structure's safety and reliability under the design load.And the structural surplus quantity is enough under 1.7 times the design load.Finally,with all of the above studies,it is shown that steel-concrete joint section is reasonable and has high security reserves.And the force transition system is reliable,clear and smooth enough.The design is reliable in engineering.