Renovation of Tacitus Bridge near Ewijk
Arup and Royal Haskoning and Greisch joint venture
Ewijk, North Brabant, The Netherlands
PRINCIPAL CONTRACTOR: CVB
INTERNATIONAL SUPPLIER AND SUB-CONTRACTOR FOR THE CABLE REPLACEMENT WORKS: Freysinnet
KEY TEAM MEMBER: Victor Buyck Steel Construction
KEY TEAM MEMBER: Mageba Structural Bearings
The 1055m long Tacitus Bridge, near Ewijk, The Netherlands, carries the A50 motorway over the busiest waterway in Europe. Its rennovation was a unique project, with an innovative solution for overcoming the effects of fatigue cracking in the steel orthotropic deck. The bridge was gradually jacked over its length to provide an increased clearance of 1m in the main span. To strengthen the bridge the existing locked coil stay cables were intricately replaced with parallel strand cables, and special tension bearings were developed to address the effects of increased uplift in the cable stayed back spans.
Tacitus Bridge is a 40-year-old road bridge over the busy river Waal, was faced with many challenges: minute cracks had been discovered, caused by heavy traffic passing repeatedly over its steel roadway under the asphalt, which if left unattended could have jeopardised the bridge. Additionally it was hoped to increase the clearance over the river by 1m. In these circumstances, it is easy to see how it may have been the end for the Tacitus Bridge without the involvement of dedicated engineers.
The engineers devised solutions for the bridge's challenges, re-engineering the structure to be stronger and higher than before and fit for at least another 30 years of hard use. They achieved this by lifting the main span up by 1m and replacing the supporting cables with 246km of new cables in a careful sequence that allowed river traffic to continue uninterrupted. As a result, the forces in the cables were much higher than originally and they were secured with a device capable of resisting up to 1000 tonnes of force. Furthermore, the steel roadway was reinforced with a special high strength concrete layer to protect it from the effects of heavy modern traffic and the cracking that can otherwise result.
The rigorous approach to re-engineering this bridge with increased river clearance demonstrates a remarkable approach to upgrading and re-using large infrastructure that sets a standard for all.