Large tonnage machine and bridge construction method

The present invention discloses a unit of an large tonnage and bridge construction method, large tonnage includes a bridge bridging machine main beam, the front contact beam girder, the girder beam contact main frame structure consisting of the main frame structurally sequentially connected with a central support means is provided, before the auxiliary support means and the auxiliary rear support means; large tonnage construction method including bridging bridging machine machine via step, the via hole conversion step to the frame beams, the beam bridge gantry step to girder via conversion step, and the end cross girder normal conversion step of the construction process variable span, small curve segments and pack construction step construction process field operation. Prefabricated bridge using the present invention to solve the large span, large tonnage, a small curvature, a multi-span and amplitude changes, and frequent transitions Condition bridging machine installation, having a safe, efficient, easy operation and maintenance, construction loads as well as good stability dispersing advantages.