The footbridge in Creil designed by Jean-François Blassel wins the "Engineering Structures" prize at the 2017 "Equerre d'argent" awards presented by "Le Moniteur"

RFR provided design services on this project

Symbolising the urban regeneration taking place in Creil (northern France), the Nelson Mandela footbridge glides delicately across the landscape. Open to pedestrians and cyclists, the 112 m-long structure spans the river Oise and connects two separate districts, one urban and the other green: the right bank is a derelict industrial area which is now undergoing regeneration, while Ile Saint-Maurice, along the left bank, is a vast area of parkland next to a wooded hillside.
Detailed description:

The type of structure selected for this footbridge is a single-tower suspension bridge reflecting the dissymmetrical nature of the site, between the built-up Place Fichet on the right bank and the green parkland of the left bank. The imposing size of the single tower is not a drawback, since it blends in with the tall trees and creates a strong symbol for the site.
Opting for a suspension bridge overcame technical constraints related to gauges and the requirement to blend in harmoniously with the environment. The main bridge span crossing the river Oise is 80 metres long.
The constraints of the river itself and the type of structure governed the construction method used. Building the bridge on-site and then launching it was impossible, as was building it on scaffolding. The solution adopted was to erect the tower and the suspension cables first, and then gradually assemble the deck in small components beneath these cables.
When the concrete deck is assembled its geometry varies, and allowance for this is made by inserting temporary hinges between the prefabricated components. Following completion of assembly, the secondary hangers are fitted and the joints are grouted.