MANUFACTURING METHOD OF COMPOSITE STEEL BOX GIRDER AND CONSTRUCTION METHOD OF BOX GIRDER BRIDGE USING SAME

摘要

The present invention relates to a construction method of a box girder bridge, comprising: a girder preparing step of preparing a steel girder formed of an upper flange, a lower flange and a pair of webs and having a central portion in the lengthwise direction, which is opened at the upper side thereof and has a sectional surface in the shape of 'U'; a girder supporting step of supporting at least one or more steel girders on the bridge bearings of a bridge lower structure to be separated at a preset interval in the traverse direction; a first foam mounting step of mounting first foams between the upper flanges of the steel girders for pouring concrete for a bridge deck so that the central sections of the steel girders, which have the sectional surfaces in the shape of 'U', form closed sections; a second foam mounting step of mounting second foams into the spaces between the upper flanges of the steel girders, which are separated at the preset interval in the traverse direction, and to the upper flanges at the positions of the outermost overhanging beams of the steel girders so as to pour concrete for the bridge deck; an iron-bar arranging step of arranging iron bars to be buried in the bridge deck concrete at the upper portions of the first foams and the second foams; a partial deck composite step of composing the concrete of partial decks, which forms closed sections with the 'U'-shaped steel girders, by pouring fresh concrete to the first foams so as to cover the exposed open portions in the centers of the steel girders, which have the sectional surfaces in the shape of 'U'; and a deck composite step of composing deck concrete in a preset thickness on top of the second foams and the partial deck concrete. According to the present invention, it is possible to construct a bridge with superior resistance capacity while minimizing the amount of steel materials used via a process that is simpler than the prior art.