The project consists of a walkway over the M-503 highway in Pozuelo de Alarcón, within a cycle-pedestrian path in the municipality.
The crossing is resolved by a cable-stayed structure with a constant edge that is accessed by side ramps on the north abutment and continues on the south one to the walkway over the M-508, it is projected with a length of 80.00 meters of light in a single spam.
The walkway is very slender with a depth/span ratio of 1/67. The useful width is 4.50 m, which is divided into 2.25 m for cyclists and 2.25 m for pedestrians, platforms physically separated by the central beam, which prevents traffic interference when crossing the walkway.
The deck is supported by a steel pylon inclined on the horizontal with a height greater than 28.00 m from the level of the deck. 13 pairs of stays start from the pylon to support the deck every 4.75 m. The rear part of the pylon is retained by a single pair of cables anchored to the foundation.
To guarantee the stability of the deck and the anchoring of the retaining cables, the deck is extended at the rear of the pylon in what we will call the tail of the walkway and which is half hidden in the walls of the access ramps.
The minimum clearance of the walkway over the link lanes is 5.50 meters. The exit lane of the roundabout from the M-503 is the one that determines the height of the structure.
The seemingly simple structure on the outside is extremely complex in its design and construction, with countless structural details and steel thicknesses that have reached up to 80 mm in some areas.
The construction procedure of the cable-stayed walkway has been carried out without the need to make any traffic cuts on the M-503. Once the foundations and abutments were built, two metal towers were placed as temporary supports. The deck was mounted on them in three sections that were welded on site. After that, the tail and the metal pylon were placed, which was assembled as a single piece.
Subsequently, the cables were threaded and a protocol for tensioning the 28 ones was followed, starting to tension from the stays closest to the pylon. The tensioning was being controlled using strain gauge bands placed on the bars and the instructions given by the Works Management according to the final loads obtained. Once the tensioning was completed and the bridge had been lifted from the supports, the temporary towers were removed.
Technical Assistance to the Construction Mangement