El viaducto sobre el Río Nalón, un puente mixto de carretera con un vano principal de 110 m de luz

Viaduct over Nalón River, a composite steel-concrete road bridge with a 110-m span

The bridge over the Nalón River formed part of the Works to separate the carriageway on road AS-17 between Avilés and Puerto de Tarna, in the Riaño-Sama section of the road, in Asturia, has been designed by IDEAM and it is an example of the development of the double composite twin girder technology, in the typology of ?strict-box? girder, with a bridge with a 110-m central span and lateral concrete prestressed spans. The imbalance of the central span length against the lateral spans obliged the use of inverted supports at the abutments, which worked under compression. The article contains a description of the various stages of the construction of the viaduct, and different details as the transversal H-shape frames, and the anchorages of the prestressed tendons in the twin steel beams.