This significant bridge is situated in Asturias, in northern Spain and was inaugurated in June 2006. The main characteristics of the Navia River Viaduct are the two 160m central spans held up by two arches built on the prestressed deck. The arches are each composed of 17 pairs of parallel stay cables, which descend through the bridge deck to the piers at either end of the arches.

The bridge has 11 spans and is built with precast segments - making a finished length of 905.4m in total. The precast segments were placed using the cantilever method and by means of a self launching girder.

The deck was prestressed with more than 900t of post-tensioned steel, including external and internal BBR CONA tendons, and was undertaken with an hydraulic auto-propelled robot which placed the stressing jacks inside the deck.

The deck interior prestressing is made up of 356 BBR CONA 1906, 864 BBR CONA 2406 and 52 BBR CONA 3106 anchorages. Over the permanent piles there are 30 BBR CONA 2406 and 132 BBR CONA 705 anchorages. Alongside the two arches, there are 12 BBR CONA 4206 external prestressing tendons totaling 320m in length. Also, in the arches anchorage zone, there are a further 64 BBR CONA 2406 anchorages. The deck positioning was carried out using four 1700t vertical and eight 160t horizontal synchronized jacks, equipped with force and displacement instrumentation.

The arches consist of a metallic box filled with concrete and their anchorage bases to the deck have 84 bars 40 type 938/1030. The bars were stressed before the stay cables were hung from the arches. There are 68 BBR DINA hangers which are joined to the arches by means of BBR Pin-Open Sockets made of cast steel. At the other end of the cable, the movable anchorage passes through the deck to the underside, where each pair of sty cables were stressed with two 300t jacks at the same time.

Each of the 68 BBR DINA stay cables was identified and marked because they were associated with their own individual cast steel piece. The installation began by hanging the cast pieces in the arches using a raising tool from which the pieces were supported while the pin was partially inserted.

The BBR DINA cables were fixed to the sockets by means of locking bolts. A crane was used to hang the stay cables from the cast pieces and lifted them until the end lower cable could be inserted into the form pipe. Then the cables were lifted so that the upper cable ends could be fixed into the anchorage.

The final position of the stay cable's active anchorage, after stressing, was calculated according to its lengthening. That is because the force applied to the cables changes, depending on tis relative position, length and temperature. When the stay cables were in position, in many cases the stressing sleeve overhung from the support plate and the lock nut could be turned. Conversely, the longest stay cables which had lengthened considerably, had the stressing sleeve inside the form pipe before stressing. So the lock nut was turned after the stressing operation.

The equipment used to stress the stay cables included a jack extension which rested on the support plate and allowed the lock nut to be threaded during the cable stressing, a jack with a 300t force at 700 bars and a load cell to show the force applied to the stay cables. To stress the cables, a pulling rod was attached to the stressing sleeve

Once the 68 stay cables were stressed and the projecting cable extremities were filled with wax, the two central temporary piles under the arches were removed using four 230t heavy lifting jacks. The heavy lifting unit's jacks were synchronized by a computer and the lowering was achieved with great precision.