This multi-span cable-stayed bridge with a typical span of 105 m, serving the “Cantábrico” Highway at some 15 km from Bilbao, has got a continuous deck with composite cross-section. Its double curvature in plan is interesting as a three-dimensional structure that, through its flexibility fits really well within its environment.
Located in the central line of the bridge, the five steel pylons rise to a set of stays that radiate looking for their anchorage within the deck, resulting in a transparent surface that is well perceived by the drivers. In fact, such radiating cables warn the drivers against the rather closed curves at both ends of the bridge.
The construction procedure was very special in the sense that each composite deck span was assembled on the ground and raised to its place by means of hydraulic devices which were located in the piles.
The important deformations under the self-weight were subsequently compensated by the prestressing of the stays.
A neat and clear structure encompasses the meandering axis of the motorway. The composite cross-section of the curved deck, with its projecting out diaphragms, creates a sense of virtual impression close to a vertebrate body.