Construction Technology Of Main Structure Of The Large Span Whole Welding Steel Basket Arch Bridge

In recent years,the domestic demand for architectural aesthetics is more and more high,in the municipal bridge design in the extensive use of large-span and unique new form of structure.These new types of bridges put forward higher requirements for the construction units,especially in the construction of river-crossing bridges,how to reduce the construction work of on-site cofferdam to ensure the normal flow of the lower river and navigation is the primary problem,At the same time should also consider a reasonable period of time to minimize construction costs,so that the construction of the environmental impact of a minimum.Compared with the construction of general bridges,the construction of municipal bridges in cities is limited,and the research on the coordination of domestic municipal bridges and the selection of technical methods is lagging behind.Based on the construction experience of the domestic municipal steel arch bridge in recent years,the design of the steel structure of the typical basket arch bridge,the assembling and pre-assembling of the temporary steel frame and the design of the temporary bracket are discussed in this paper,with the background of "Dongjiu Meilin Bridge Project in Yixing City",The main steel bridge deck and the installation and control of steel arch and other key technologies were studied.In the construction example,it effectively solves some technical problems in the processing and construction of the city-wide steel structure basket-arch bridge,and accumulates the construction experience of the whole steel arch bridge.This paper introduces the history,current situation and development trend of continuous steel arch bridge at home and abroad,and expounds the main construction method of steel arch bridge at present.Taking the background engineering as an example,the quality control and deformation control of the whole welded steel arch bridge in the process of manufacturing and processing,as well as the segmentation and segmentation of the structure based on the transportation conditions are described.At the same time,according to the steel box girder structure size,butt weld,local welding plate thickness of the characteristics of the welding mode and welding stress control conducted in-depth study,take a variety of ways to control the welding stress.Site assembly and installation of the construction process to local conditions,the use of on-site assembly plus pre-assembled method,this method to solve the larger segment of the transport problems,and the overall site assembled at the same time the site of the two pre-assembled,Segmented precision control is more favorable.According to the characteristics of urban transport and on-site installation of the conditions used "door hanging through the river walk construction" approach,this method to avoid the construction,the river set up a large number of cofferdam and heavy machinery travel channel.The rail foundation is steel pipe piles into the riverbed.The gantry crane girder rails are installed at the top of the steel pipe piles.Steel pipe piles and track beams are arranged on both sides of the bridge,and the track is laid on the track beam.Steel deck in the assembly site on both sides of the assembly molding,gantry crane by the overall travel in place.The method has the advantages of high efficiency,fast construction speed,flexible construction,high safety and reliability,and construction gantry crane walking on supported track girders.It can not be affected by the lower river,and can be assembled on both sides of the river to effectively ensure the construction quality.And formed a "gantry crane across the river walking construction method."...