| 摘要 |
PROBLEM TO BE SOLVED: To give reinforcement in the direction parallel to and perpendicular with the bridge axis without significant increase of a dead weight rate, and prolong the fatigue life of a bridge by providing reinforcing members consisting of FRP lateral girders and vertical girders on the lower surface side of a floor boards, and then fastening the lateral girders to steel main girders. SOLUTION: A concrete floor board 4 is mounted on a pair of steel main girders 3, 3 extending in the longitudinal direction at both sides. Lateral girders 1-1 of an FRP reinforcing member 1 are joined to the steel main girders 3, 3, by bolts 2, and vertical girders 1-2 of the FRP reinforcing member 1 are arranged and joined by bolts so as to be adjacent to the bottom of the concrete floor board 4 and the lateral girders 1-1 of the FRP reinforcing member 1. Since stress exerting the concrete floor board 4 runs to the steel main girders 3 via the FRP reinforcing member 1 not only from flanges 5, the burden stress of the concrete floor board 4 and flanges 5 on the steel main girder can be reduced, resulting in a prolongation of the bridge. In addition, use of a lightweight FRP material as a reinforcing member can restrain the weight increase of the bridge due to such reinforcement in minimum, thus lessening attendant work accompanied by increasing of dead weight. |
