REPLACING METHOD FOR BRIDGE GIRDER

PROBLEM TO BE SOLVED: To provide a replacing method for a bridge girder by which replacing work of the bridge girder can be quickly executed without using a large crane. SOLUTION: In a state that an existing bridge girder 1 erected on adjacent piers in the bridge axis direction is supported from the lower direction by jacks 4a laid on trucks 4b, the both ends of the existing bridge girder 1 is cut off so as to become shorter than the span L of the bridge piers 3, and at the same time, the replacing work of the bridge girder is executed by a replacing preparing process to construct a new bridge girder 2 to be erected on the bridge piers 3 on the existing girder 1, a bridge girder lowering process to lower the existing bridge girder 1 by the jacks 4a in a state that the new bridge girder 2 is laid on the existing bridge girder 1, a new bridge girder erecting process to erect the new bridge girder 2 on the bridge piers 3, and an existing bridge girder carrying-out process to carry out the existing bridge girder 1 supported by the jacks 4a.