Study On The Steel Box Girder Design Principle Of Prefabricated Steel-Concrete Composite Continuous Girder Bridge

Supported by the Ministry of transport construction technology projects(2013 319 814 040)“the basic theory research of constructing the extra-large-span steel trussconcrete composite continuous rigid frame bridge” leaded by the tutor,proposed the follow-up concept “ the integral prefabricated steel-concrete composite continuous girder bridge”,aiming at the steel box of the structure principle,its mechanical properties,design method are analyzed and studied in this paper.The main research contents are as follows:(1)Based on the existing research,the construction scheme of the integral prefabricated steel-concrete composite continuous girder bridge is studied: Assemble the steel box girder and the whole wide section precast concrete bridge deck in the factory--prestressed concrete bridge deck according to the design requirement--positioned the precast on the steel box girder--perfuse a cavity with concrete in order to complete the connection with concrete deck and the steel box--push steel-concrete composite continuous girder bridge on the pier.The technical economy of three kinds of composite beams building program is compared and analyzed in this paper.(2)Based on the integral prefabricated steel-concrete composite continuous girder bridge,the structural details of shear connection between bridge plate and steel beam are described.According to the working characteristics of the steel box girder,the design method and the connection about the components of the steel box and every performance index of the structure are explored.Combination of area matching and full stress method,the optimization design model of section Parameters of steel box girder is established.Optimized the steel box by MATLAB,put forward the initial optimization value of the design Parameters with different span steel box girders in this paper.(3)Based on the example project,established the bar and plate-shell finite element model of the integral prefabricated steel-concrete composite continuous girder bridge,simulated the whole process of pushing construction,analyzed the stress and deformation of the steel box under the most unfavorable conditions,discussed the influence of the size Parameters of rubber cushion on the local force of steel box in the supporting area.By simulation analysis,comparison are made on the force condition of the steel box in the construction stage of the continuous girder bridge,which are conventional prefabricated assembly-cast-in-place continuous girder bridge and the integral prefabricated steelconcrete composite continuous girder bridge proposed by the research team.