Construction methods inducing compressive stress in slab of negative moment area for type of rahmen bridge using precast girder

摘要

The present invention relates to a construction method of a Rahmen type bridge that a Rahmen bridge and a bridge of a Rahmen bridge form. A precast girder (a prestressed concrete girder, a prestressed steel composite girder, and a steel box girder) is constructed or assembled on the ground to be mounted in a state prior to installation of a parapet wall of an abutment on one end or both ends. A moment magnitude of a negative moment area is considered to arrange a sheathed steel strand with a fixing device on an end of a sheathed steel strand inside the girder on an upper end of the girder or into a blocked-out end surface in multiple steps. Then the arranged sheathed steel strand is installed to be tensioned and fixed on a rear surface of the parapet wall to pour and cure concrete to integrate the precast girder with a connection reinforcing bar and a connector for integration into the parapet wall and a slab. After the concrete is cured, the previously installed sheathed steel strand is tensioned and fixed on the rear surface of the parapet wall of the abutment. Therefore, tensile stress applied to the slab by a working load and a secondary dead load is offset.