Analysis Long Span Steel-Concrete Composite Continuous Girder Bridge Prestresse Effect

In negative bending region of long span steel-concrete composite girder bridge, the compressive pre-stress is imposed in order to reduce tensile stress of concrete bridge decks and avoid causing cracking. When adopted to tension steel as a way to impose pre-stress for bridge decks,the group of shear studs as the connector of composite continuous girder bridge has great advantages than composite continuous girder bridge with traditional shear connectors.In this paper, a large span prestressed steel-concrete composite continuous girder bridge with the group of shear studs as the connector is the object for the study, based on the existing composite girder bridge theory,applied the finite element analysis, by changing the way of shear connectors and integrating the amendmented bridge process, to analysis prestresse effects differences and similarities between the shear group studs composite continuous beam bridge and the general shear connectors of composite continuous girder bridge.In this paper,mainly includes as the following:(1) Based on the analysis of domestic and foreign scholars in research work and references,make sure the adverse effects of bridge deck caused by the negative moment in composite continuous girder bridge. For methods of reducing the adverse effects of negative moment, disclosure deficiency of the problem in existing methods. Due to concrete cracked of bridge deck of composite continuous girder bridge, analysis the similarities and differences of internal forces and deformation in the composite continuous bridge and simply supported composite bridge and the overall characteristics of composite continuous girder bridge performance under the force,then lead out the problems of the contents of this paper through the engineering example.(2) According to theoretical studies had been made out, make sure the theory of analysising internal forces of the composite bridge and capacity of the composite section. Based on composite bridge theory, clarify the difference between internal forces and ultimate bearing capacity of composite section and applicable conditions and scale.(3) Using bridge structure analysis software to proceed value emulation for the project,according to the existed research results and data based on the project, discuss rationality of the finite element model and finite element model results of the reliability and accuracy.(4) The finite element model based on the project,consider the changes in shear connectors causing the formation time changed of composite section and construction process changed with the corresponding, group of shear studs continuous girder bridge finite element model is proceeded analysis of variable parameters,based on the the results of group of shear studs continuous girder bridge and composite continuous girder bridge with traditional shear connectors finite element model, analysis of the similarities and differences of the internal forces and stress and deflection of composite section under tensional prestress in composite beam bridges,point out the issues that need to pay attention and proposals in the design and construction process of the group of shear studs continuous girder bridge.