The Maranura bridge over the Vilcanota river is located in the Sacred Valley of the Incas, the Andes, 30 km from the Machu Pichu Sanctuary, in the Cusco region and has been promoted by the Ministry of Transport and Communications-PROVIAS.
It has a 202 m. total length, 150 m corresponding to the parabolic bow of 15 m of arrow (1 / 10L) that crosses the channel at a height of about 100 m.
Given the location of the bridge in a remote area, the planned solution proposed light and small elements to facilitate its construction.
For this reason, a light configuration for the arch was chosen by means of a double thread with an octagonal box section lightened internally in order to be able to be executed by folding down semi-arches.
The threads are transversely braced every 15 m in the supporting sections of the columns by means of rectangular beams.
The 11.70 m wide deck was also solved with a light and simple solution to build by means of a “π” cross section of reinforced concrete the nerves located in the vertical of the arches on which they are supported by means of pillars. rectangular. The lares support is carried out on neoprene supports sized to achieve sufficient seismic isolation so as not to penalize the behavior of these and the arch.
The initial construction system for folding the semi-arches was modified at the request of the constructor by a construction on a metallic auxiliary self-supporting arch, since he had recently used this system in another work and the formwork modules could be adapted without too much complication to the geometry of the Maranura arch.