During the conception phase of the design for the bridge and walkway over the Itajaí-Açu River, we took into consideration the role bridges represent to a city and its residents. We understand that an urban bridge represents more to the city than just utility: it serves as a reference, an instrument that helps boost the self-esteem of its dwellers. The competition intended to select the best proposal for a bridge and a footbridge for the city of Blumenau, Santa Catarina.
In Blumenau, bridges are known for resisting floods, and much has been learnt about them, not only from an engineering standpoint, but also due to the ability of its inhabitants to rebuild once normality has been restored. In this design, we looked to offer solutions that would facilitate coexistence following floods, when faced with large investment requirements.
The architectural design approach adopted was that of a cable-stayed/extradosed bridge suspended unilaterally, with a main span of 140 meters.
The cables were arranged in a quasi-straight line so that we could minimize transverse bending of the pylon. For this reason, the pylon was placed with a slight outward inclination. Due to the great rigidity of the superstructure, the distance between cables is relatively long (up to 20 meters). However, to comply with the standards for the distance between stays, 6 cables were distributed on each side – within the main span, 16 meters apart.
For the footbridge design, the chosen approach was that of a cable-stayed bridge with a main span of 150 meters, with the smallest cable slope set at approximately 15.50°, which is close to that found in extradosed bridges.
The use of two planes of stays resulted in an open superstructure that does not require great torsional stiffness.
The grounded section of the bridge, up to 15 m beyond the pylon is made of concrete and was conceived as a reinforced concrete double T-beam that is suspended freely between the pylon and the meeting point, reducing the number of supports needed in the floodable area.
Location: Rio Itajaí-Açu – Blumenau/Santa Catarina
GPS Coordinates: 26°55’08.9″S 49°03’51.5″W (see on google)
Status: Not built
Authors: Sotero Arquitetos, JMB Engenheiros Associados e Luiz Gaudenzi Arquiteto
Images: Collection Sotero Arquitetura