PREVENTIVE CONSTRUCTION OF MAIN-GIRDER LATERAL BUCKLING TO BE GENERATED IN REPLACEMENT OF FLOOR SLAB OF COMPOSITE GIRDER WITH PRECAST FLOOR SLAB

摘要

PURPOSE: To prevent lateral bucking by forming a space of a box-removing section in the main-girder direction, temporarily fixing a precast floor slab with the space as distance between fixed points onto a main girder, and constraining movement in the lateral direction. CONSTITUTION: Several all-screw studs 8 are welded an implanted to the upper flange 1a of a main girder 1, and the screw studs 8 are positioned into the box-removing section 5 of a floor slab 3 placed on the girder. The studs 8 are inserted to a fixed block 9, and the fixed block 9 is installed onto the upper flange 1a of the main girder 1. Flat jacks 10 are inserted among the wall surfaces 5a of the box-removing section 5 and the wall surfaces 9a of the fixed block 9, and the precast floor slab 3 and the main girder 1 are fastened. When the precast floor slab 3 is built completely, the fixed block 9 is removed from the box-removing section 5, concrete is placed into the box-removing section 5, and the main girder 1 and the precast floor slab 3 are composed. Leaf springs 4 are removed, thus completing operation, in which the floor slab of a composite girder is replaced with the precast floor slab 3.