Research On The Mechanical Properties Of Joint Of Steel-Concrete Hybrid Continuous Beam Bridge

The steel-concretehybrid girder bridge issystem that using steel-concrete combined sections to contact concrete beams and steel beams with joint structures at proper position in vertical.Steel beam was used to instead of the traditional concrete beam on all or part of the span of hybrid girder bridge.Steel beam reduces the structural weight to a large degree,enhances the ability of the bridge span and improves the force performance of the bridge.Hybrid girder bridge has been widely used in practice and studied as the hot issues since its appearance.The steel-concrete joint section is the weak part of hybrid girder bridge,whose design is related to the quality of the whole bridge.And the force performance of steel-concrete joint section has a strong practical significance.The force performance of hybrid girder continuous girder bridge joint section was researched in this paper.First of all,referring the latest research results of hybrid girder bridge steel-concrete joint section at home and abroad,different structural forms of steelconcrete joint section are classified.There are macroscopic analysis of how to bear the load from the steel beams,and the application of various forms for joint section.The operational principle of beam steel-concrete joint section connectors and calculation formula for the bearing capacity are discussed.Secondly,based on the engineering of 318 national road section of long bridge in Zhe Jiang province,the whole hybrid girder bridge calculation model is established.Considering the influence of dead load,prestressed effect,moving load,concrete creep effect for 10 yearsand temperature effect.The analysis of steel-concrete joint section of how to bear the load from the steel beams based on the limit state of load combinations.The load bore by joint section is applied to the finite element model as the internal boundary under the limit state,and deformation and stress state of steel-concrete are analyzed in the joint section.The analysis resultsshow that the joint section of long bridge is smooth in stiffness transition and good in force performance.Finally,due to the simplification of model of joint section,it’s not clear of the stress state of PBL connector in the joint section.Take out a single connector and concrete contacting with the connectorandconsider nonlinear of concrete materials and the contact relationship of two kinds of material in the hole within the joint section.Flat section assumption is made on the joint section pressure surface,assum that hybrid girder is under the conditions of bendingand the stress state of the joint section of tensile stress area and compression area is analyzed.The results show that the concrete stress levelofcompressive zone of columns hole is relatively balanced;The stress value of concrete intensile stress areaofconnectorclose to bearing plate hole is bigger,andthe stress value of concrete far from bearing plate hole is low.When PBL connector is in compression zone,it will make full use of its shear capacity to a greater degree.