Study On The Assembled Construction Plan And Calculation Parameters Of Rectangular Concrete-filled Steel Tubular Composite Truss Bridge

In the process of industrialization of bridges,the technology of accelerated bridge construction based on prefabrication has received extensive attention.Its core elements are standardization of bridge design,component manufacturing and factory assembly,and construction site assembly.As a new structural type of bridge,RCFST(rectangular concrete-filled steel tubular)composite truss bridge has the characteristics of light structure,convenient installation and obvious economic and technical performance.It can meet the requirements of accelerated bridge construction for factory prefabrication and on-site assembly,and can be used as one of the options for the industrialization of medium-span bridges.Based on this,this paper selects the key problems of standard design and assembly construction of RCFST composite truss bridge to design and compare construction plans,and provides reference for the design and construction of similar bridges.Based on this,this paper combines the perspective of standardization and assembly of RCFST composite truss bridge,and attempts to provide design reference for assembly engineering solutions for practical projects.The main research contents are as follows:(1)The core idea of accelerated bridge construction technology under the background of bridge industrialization and the advantages and characteristics of RCFST composite truss bridge are expounded.The research status and engineering application of composite steel truss girder bridge are summarized,and the shortage of research on the bridge type assembly construction scheme is put forward.(2)The standardization design idea of 50、60、70、80m medium span RCFST composite truss bridge and the overview of structural bar parameters are presented.The form and division principle of transportation unit and installation unit are proposed from the fabrication.The construction method of the truss and precast concrete deck of the composite truss bridge structure is discussed in detail,and reasonable combination of construction method,and the construction method is reasonably combined with the installation unit of the(4×80)m span standard drawing.(3)Based on the(4×80)m standard span RCFST composite truss bridge,the design of incremental launching,lifting and cantilever assembling construction scheme of the concrete-filled steel tubular truss is carried out.Starting from the perspective of the process behavior and construction feasibility,a reasonable plan is recommended.Through the calculation,the feasibility of factory prefabrication and on-site installation of RCFST truss is proposed.The transition of the truss from the joint force to the "beam" bending of the lower chord during the construction process is analyzed.(4)From the perspective of controlling the tensile stress of the bridge deck in the negative moment zone,the specific construction scheme considering the construction sequence and the process technology is selected,and the erection idea of the precast deck corresponding to the three methods of the truss construction is provided.