CONSTRUCTION METHOD FOR OVERALL LIFTING AND CLOSING OF LARGE-SEGMENT STEEL BOX GIRDER

The present invention is applicable to the field of constructing upper structures of bridges over water, and provides a construction method for overall lifting and closing of a large-segment steel box girder. In the present invention, closure dimensions of a steel box girder may be obtained according to actually measured data and theoretical calculation of a closure. The extra length of the large-segment steel box girder is cut off in advance in a processing factory. After being transported to a site, the steel box girder is hoisted to the closure as a whole at one time by using a deck unit erection crane. After being precisely aligned, the steel box girder is first temporarily locked, and weld seams of the closure are then welded to implement rapid closing. Therefore, in the present invention, no patching segment needs to be reserved during the closing of the large-segment steel box girder, the steel box girder can be precisely processed in a processing factory according to the dimensions, and after being transported to a site, it can be hoisted and installed directly, thereby implementing precise and rapid closing.