VIADUCT OVER THE STRAIT OF PAREDES

This viaduct is composed of a strict double action box girder with a span arrangement of 40 + 72 + 88 + 104 + 76 m. The remaining superstructure of the bridge is implemented through piers, deep and shallow foundations made out of concrete.

The most relevant feature of the viaduct is the phased launching of the bridge deck, which is carried out by using the “Abacus” system. This system allows launching this kind of constant depth deck without having to relinquish the advantages of a variable depth deck during final construction stage and in service. This is achieved by means of T-shaped piers placed at adequate spots. These piers are composed of a vertical shaft and two horizontal lintels set symmetrically with respect to the pier’s centerline. During the launching process, the deck bears on top of these abaci. Once the launching process is finished, the deck is rigidly connected to the abaci so to configure a variable portal-frame system over the larger spans, which is optimized with respect to the different span lengths.