Geneva Stadium Footbridge - Rehabilitation of the Deck

However, major cracks appeared during the bridge’s construction and an expert assessment led by the engineering firm INGPHI SA in 2010 revealed three issues:

• a too-low thickness of the composite slab and a low positioning of the reinforcement, leading to a flexural strength of the composite slab above the cross sleepers that was too weak and resulted in the appearance of cracking;
• a too-weak connection between the composite slab and the wood frame, not allowing, for example, a taking up of the load caused by the braking of maintenance equipment and therefore causing a risk of the composite slabs slipping on the sleepers;
• a loss of load-bearing capacity of the structure due to cracks, combined with a loss of durability of the structure. Structural safety with respect to struct force and punching load was not assured. 

As structural safety was no longer guaranteed, it became necessary to reinforce the structure by reinforcing the concrete slab on the one hand and the connection between the concrete slab and the wooden structure on the other. Reinforcement of the connection between the slab and the structure was achieved by creating rigid connections between the slab and two cross sleepers in order to take up the loads caused by the braking of the maintenance equipment and strengthening of the connection with the two other sleepers in order to take up the forces caused by thermal expansion and shrinkage.

Photo ©INGPHI SA

Reinforcement of the concrete slab was achieved by installing a thin 45 mm layer of reinforced Ductal ^® UHPC. This Ductal^®  layer plays a dual role, reinforcing the existing structure on the one hand and ensuring the sealing and therefore the durability of the structure on the other. 

This major maintenance and refurbishment work, carried out during the spring and summer of 2019, should allow the Sports Bridge to be reopened in time for the inauguration of the new CEVA line and therefore offer fans of soft mobility a safe passage between Lancy-Bachet station and the Praille stadium.