The 516 Arouca – Suspension Bridge connects the two banks of the Paiva River, together with those of the parish of Alvarenga and the Union of Parishes of Canelas and Espiunca, in the municipality of Arouca, district of Aveiro, in the northern region of Portugal.
Located next to Paiva Walkways, the “516 Arouca” was built with the aim of consolidating the active tourism project in the Paiva valley, facilitating access to the nascent area of Arouca UNESCO World Geopark.
The approximate topographical coordinates of the bridge center are M = -3352.2 and P = 143928.7. The location allows a wide view over the river, which runs 175 m below, and over the Aguieira waterfall.
The pillars, 36 m high, are intended to lift the suspension cables, reducing their efforts and mooring forces in the anchoring blocks. Its inverted A shape is intended to incline the plane of the main (catenary) and secondary cables so that they present vertical and horizontal components that can simultaneously respond to the actions in the respective directions.
The foundations on the right bank (Alvarenga side) are straight, with the foundation massif resting directly on rock.
On the left bank (Areinho side) surface sandstones were found, with sufficient strength but breakable and subject to erosion over the years. For this reason, the foundation massif was laid on a set of 42 micro-piles, embedded in compact rock, at a depth of about 9 meters.
The pillars are in reinforced concrete and were built with a climbing formwork system. The span of 516.50 m between pillar axes allows it to exceed the 494 m of the previous longest suspended pedestrian bridge in the world, located in Switzerland (Bridge Charles Kuonen).
The main cables are made up of seven HD 8 K PPI cables with a diameter of 40mm and the hangers by cables with a diameter of 12 mm, both galvanized. The trays were manufactured with S275 steel, treated by hot galvanizing, by immersion in a tank with fluxing zinc. The assembly of the cables and deck spans was carried out with the support of a “bondin” winch installed between the two crossbeams of the gantries.
Assembly was performed from one bank, with components transported from the other bank.
The design of the board had 3 main objectives:
The main cables have their ends fixed on mooring massifs, in turn anchored to the rock massif of the hill. In the following photo you can see the cables, the mooring devices and the anchor heads (one of them with a load cell).
The 127 deck spans are labeled with each other and suspended, from the hinges, by two types of hangers: The main hangers, which attach to the hinges and support the vertical and horizontal actions, and the secondary hangers that tie the top of the frames. and minimize the torsion effects that are caused, for example, by people walking along the bridge and in case they approach a guard to observe any occurrence in the river.
On 11/11/2020, Itecons and LNEC carried out dynamic tests on the completed bridge to verify that the behavior of the bridge corresponded to that considered in the theoretical calculations. The results were positive and it was considered that the bridge met all the safety conditions to be able to receive users.
Due to the pandemic, and to avoid large gatherings of people, the bridge was only opened and opened to the public in May 2021.
The trials were carried out with the collaboration of a group of volunteers.
The bridge was dimensioned to receive, simultaneously, 1815 people. However, for the time being, the visit to 516 Arouca is limited to an approximate number of 70 simultaneous visitors, always accompanied by a guide and lasts approximately 1 hour and 30 minutes, requiring advance booking online.
