Construction Control And Construction Technology Of Cable Stayed Bridge Of Large Span Composite Beam

The composite girders have been widely used at home and abroad due to its economic efficiency,the advantages of steel and concrete of playing their respective features properly,and the convenience for construction.The composite girder cable-stayed bridge is a multiple indeterminate system with complex structure and difficult construction.Therefore,it is necessary to study the construction control and construction technology of the composite girder cable-stayed bridge.In this thesis,a ?-shaped composite girder cable-stayed bridge is taken as the engineering background to study construction control,and make clear the specific implementation of the construction control.At the same time,the key technical problems in construction of the composite girder cable-stayed bridge are discussed.Firstly,the development of cable-stayed bridge with composite girder at home and abroad,the research status of construction control and the construction technology of cable-stayed bridge with composite girder are briefly introduced.The problems existing in the construction control and construction technology of the composite girder cable-stayed bridge at present are described.Based on the actual situation of the project,the paper puts forward the general construction control idea that uses the accurate steel beam installation height to control the main girder shape for accurately controlling cable force and structural stress based on accurate simulation analysis and prediction.The high precision closure of the ?-shaped composite girder cable-stayed bridge,and the high precision control of the shape and cable force are realized,and the satisfactory effect is achieved finally.Secondly,in view of the bridge foundation is located in the large diameter thick pebble layer,the paper puts forward the composite supporting scheme of the foundation pit,i.e.the combination of “supporting row pile + top beam + high pressure rotary spray pile sealing curtain wall”,to solve the foundation construction in the northwest thick pebble layer area;and simultaneously the “narrow space asymmetric cyclic tensioning cable” construction technology to effectively solve the problem that the symmetrical construction of cable can not be implemented due to narrow space.Finally,the research on the manufacture,installation and closure technology of steel-concrete composite girder is carried out.This paper describes the manufacturing technology and symmetrical assembly technology of steel-concrete composite girders,gives the adjustment control methods for posture adjustment,elevation control and axis control during the construction of cantilever assembling overhead auxiliary pier of the main girder,and puts forward the closure technology of side-span “pre-bias incremental launching method” and mid-span “temperature deformation forced method” to effectively solve the problem of low-temperature closure in northwest region.