Varying gradient bridge superstructure stepped advancing system - uses packing members under guide track to vary height of advancing sections

摘要

The stepped advancing process is used for erecting a bridge superstructure (10) made up of reinforced concrete sections (1-9). These are moved forward to their final position in stages, using a sliding track on their underside, on sliding bearing attached to peirs (13) forming part of the bridge support structure. Packing units (19) are on some, at least, of the concreting sections, for varying their height along the course of the superstructure. These are of such dimensions that the sliding track runs in a curve, which may vary in curvature along the superstructure. The packers may be detachably joined to the sections, and removed when the final superstructure position is attained. They may be made of prefabricated concrete components.