Process for construction of bridges, in particular motorway flyovers

Claim 1

In a process for construction of a bridge with at least two piers and a continuous deck resting on the said piers, the said deck comprising at least a central span between two successive piers and two lateral spans extending respectively on either side of the said central span, the said process in particular comprising, to construct the said deck, assembling and fastening by means of prestressing reinforcements a plurality of prefabricated segments each having two opposed end faces, each segment being applied with one of its end faces against the adjacent end face of the immediately adjacent segment, the improvement comprising the following successive steps: adjacent to each pier is erected a falsework having a substantially horizontal upper platform on which are arranged substantially vertical main jacks provided in their lower portions with sliding or rolling organs enabling the said jacks to slide or roll on the said platform; the segments of a deck portion which comprises a fraction of the central span and at least a fraction of the lateral span associated with the pier in question are then placed successively in position over each of the said platforms, bearing on the said platform by means of the said main jacks, and the said segments are joined together by means of temporary fastening organs, the deck portion thus formed - which is supported by the said main jacks - then extending over the upper face of the pier in question and out of contact with the said face; the main jacks supporting at least one of the two deck portions associated with two successive piers are then made to roll or slide on their platforms, so as to move the said two deck portions towards each other until their mutually facing end faces contact each other; the segments of the assembly formed by the said deck portions are then permanently fastened together by means of prestressing reinforcements distinct from the temporary fastening organs used before, so as to form a continuous deck; the said continuous deck is lowered by operating the said main jacks until it rests on the piers of the bridge; and the said temporary fastening organs and the said falseworks equipped with their jacks are disassembled.