The Pontevedra Provincial Council together with the Portuguese INTERREG Administration called an international competition for the construction of a pedestrian bridge between the right bank Goián (Spain) and the left of the river Miño Vila Nova de Cerveira (Portugal). A park with the restored remains of an old fortress at the foot of a river beach is located in the Spanish abutment. These remains are from the 18th century.
On the Portuguese side, a natural park connects with the urban core of the town. This project enhances the brotherhood between both banks of the Miño, which share a privileged natural space dominated by the river and seasoned with a historical heritage embodied in the fortifications of both towns, thus generating the first cross-border urban park on the Iberian Peninsula “Ecoparque O Castelinho -Espazo Fortaleza”. The motto chosen for the competition was IRMANDANDE.
A suspended typology walkway is designed, which allows crossing the Miño without the need to locate intermediate piers in the river, thus safeguarding the channel from any constructive affection. The crossing over the Miño is made starting from the horizontal observation platform existing in the Espazo-Fortaleza park under the San Lorenzo fortress to the O Castelinho de V.N. from Cerveira, south of the Islet Do Castelinho. This crossing point has the great advantage of not affecting either the Goián river beach or the islet of the Do Castelinho park. Thus, any affection to this islet is saved, which due to the execution of the left abutment, it would be environmentally very affected and would occupy much of its small size.
The length of the structure is 250 meters between both abutments with a useful width of 4.00 meters and a depth of 80 cm. Two inclined pylons are designed, generating a central span of 190 meters and two lateral spans of 30 meters. The central span is suspended by two main cables that go beyond the pylons to later anchor in the ground. This double plane of cables makes its transit more pleasant and structurally collects the twists of the board.
In order to keep the side spans with the same strict depth of the main span, the pylons return below the deck, generating intermediate support that laterally embraces the structure and gives great expressiveness to these elements.
The following parameters have conditioned the choice of the suspension typology:
The need to combine accessible slopes with the clearance conditions imposed by the navigability of the river requires rigorous depth deck.
Excellent foundation conditions in the granite massif with a very shallow depth, which significantly facilitates the anchorage of the cables and allows concentrating the high loads in few support points (pylons).
Elimination of piers within the river, without affecting in any way the channel during the construction process.
The depth of the channel is already 5.00 meters at a distance of fewer than 20 meters from both banks. The bathymetric of the river shows these results. The provision of intermediate piers would force costly foundations and the construction of temporary artificial access peninsulas for the construction of said piles.
Ease of construction of the suspension solution, which allows the entire navigability of the river to be maintained throughout the construction process, maintaining the navigation channel with the prescribed gauge.
The construction solution is independent of floods caused by avenues of the Miño.
The suspension walkway by its shape, internalized by citizens, evokes a natural symbolism to “build bridges” between peoples, which is what is intended in this international Contest.
The pylons, leaning towards each other -as if wanting to touch each other- enhances the previous idea of union between both margins and symbolizes everything that this cross-border park wants.
The project solution is perfectly integrated into the serenity of the environment and the peace that is breathed between both parks. Maintaining that problematic balance between the symbolism of the structure and its formal integration.
The smooth curves described by the deck and cables harmonize with the undulating orography of the surrounding hills, favouring landscape integration, which is why it has avoided much more aggressive cable-stayed solutions typical of more urban environments.
The abutment in the Espazo-Fortaleza park is located on the elevated observation platform of the existing river under the San Lorenzo fortress. The abutment respects and merges with the pre-existing performance with minimal affection, as if it had been thought of in a single project, taking advantage of the current ramps for accessibility to the walkway.