Sancho el Mayor Bridge. Navarra. Spain. 1978.
It is a cable-stayed bridge with a single tower, without a compensation span, and therefore the rear stays are anchored in counterweights located on the edges of the highway. Tensioning is carried out from a tower located on the freeway axis from which three stay cable beams start: the front one split into two parallel beams very close together, lodged in the freeway median, and the two rear beams that are anchored in the counterweights. The three beams form angles of 120° to each other in plan, which gives the stay cables a spatial configuration.
The deck consists of a three-cell box with a central cell where the tie rods are anchored. The tie rods are formed by closed cables.
The overall balance of the structure is achieved by the polygon of forces formed by the tower, the tie rods, the deck, the tower foundation and the beam connecting the tower foundation with the counterweights.
The bridge was built by successive cable-stayed cantilevers from the tower to the end pier, using precast segments. The deck was divided into two half girders that were connected by cast-in-place concrete.
