Building of multispan bridges or the like works, by the cantilever method

Claim 1

In combination with a superstructure of a multispan civil engineering work under construction, such as a bridge or an elevated road or track, which superstructure comprises at least one two-arm beam which extends in a longitudinal direction substantially symmetrically on both sides of a previously erected pier and rests upon the latter, which two-arm beam comprises a plurality of longitudinally-consecutive voussoirs including an initial pier-voussoir which caps the said pier and two first voussoirs respectively consecutive to and bordering on said piervoussoir on either side thereof, a device for successively placing the voussoirs in position in cantilever fashion in opposite directions from said pier, said device being of the kind comprising an elongated horizontal scaffold extending in the longitudinal direction of the two-arm beam and above the same, said scaffold presenting two longitudinally-spaced end-regions and a median region located between and remote from said two endregions, and an end-support extending from an end-region of the scaffold for supporting said scaffold on an already-completed part of the work, wherein the improvement comprises a median support integral with said scaffold and extending from the median region thereof for supporting said scaffold on the said pier, said median support being a compact concentrated bearing unit subdivided into three longitudinally-consecutive and adjacently grouped bearing members, namely a central bearing member overtopping the said pier-voussoir, and two additional bearing members located adjacent said central bearing member on either side thereof and respectively overtopping the said two first voussoirs next consecutive to and bordering on the said piervoussoir, and means for anchoring said two additional bearing members to said two first voussoirs respectively.