Numerical Simulation And Parameter Analysis Of Steel-Concrete Joint Section Of Hybrid Girder Cable-Stayed Bridge

Recently,with the extensive use of hybrid girder cable-stayed bridge,the mechanical properties of steel-concrete joint section has drawn researchers’ attention.The steel-concrete joint section is located at the intersection of concrete beam and steel beam,its structural form and stress situation are complex,and it becomes one of the key structure of hybrid beam cablestayed bridge.Based on the engineering background of a hybrid girder cable-stayed bridge,the local mechanical properties of the steel-concrete joint are analyzed by the method of combining the full bridge model and the local model of the joint section.In the meanwhile,the influence of parameter variation on the mechanical behavior of the joint section is studied by using the control variable method.The main work and achievements are as follows:(1)The development and research situation of hybrid girder cable-stayed bridge and steelconcrete joint section are introduced;the internal force transfer law of steel-concrete composite section is analyzed,and the structural characteristics of steel-concrete composite section are defined.(2)The finite element model of the whole bridge is established.The internal force values and variation trends of the control section of the steel-concrete joint section in the actual construction and operation stages are analyzed,and the internal force of the control section under the most unfavorable condition is extracted.(3)ABAQUS finite element software was used to establish the numerical analysis model of the steel-concrete joint section,and the stress distribution and deformation of the joint section under various adverse working conditions were simulated and analyzed.The results show that the overall stiffness transition of the joint section is smooth,the deformation is very small,the stress is good,and it has a certain stress reserve.(4)The parameters affecting the mechanical behavior of the joint section are analyzed.The results show that when the thickness of the back bearing plate increases from 40mm to 60mm,the compressive stress of the top and bottom plates of the steel grillage chamber decreases obviously,while the influence on the concrete is is slightly smaller;when the thickness of the top and bottom plate of the steel grillage chamber decreases from 10mm to 5mm to the design thickness,the stress of the top and bottom plate and the concrete decreases obviously,and the steel and concrete are more closely combined.When the thickness of the back bearing plate is about 60mm,the thickness of the top and bottom plate of the steel grillage chamber is about 30mm and 50mm respectively,it is more reasonable.