Pont National in Paris: Our heavy plates chosen to enlarge iconic bridge in Paris

Detailed information

The pedestrian bridge

The footbridge is a very slender box girder bridge that is sustained by V-shaped posts on the existing bridge foundations. It consists of a slim line box girder with a length of 260m and a height variable from 30 to 50cm. The design was created by architect Christian Devillers, who already had building experience in this attractive city. The project was launched in January 2011.

Complex construction

There were some challenging elements present in the construction of the footbridge. Because it is slim, the exposure to vibration required further attention. Furthermore, the pedestrian bridge rests on cross-shaped plugs at the bottom and is attached with chain links to the existing bridge at top. These chain links are similar to anchors for ships.

Assembly proceedings

The assembly took place using telescopic cranes standing on the existing bridge. In addition, a special support structure for the bridge was designed for the assembly. After the welding of the plugs, this structure could be disassembled by the cranes on the existing bridge. The parts of the pedestrian bridge had to be trucked in as well as delivered by barge.

ArcelorMittal Europe - Flat chosen as steel supplier

The architect had chosen a specific paint with high gloss and reflectivity that would enable the Seine water to reflect on the structure. As such, it was of major importance to ensure excellent smoothness and surface finishes on the plates - our Gijón mill was able to meet this requirement.

For this project, ArcelorMittal delivered S355 steel grade heavy plates according to NF Acier “Fascicule 4 titre III des Ponts et Chaussées,” which is mandatory for steel supply concerning bridges in France. In such cases, the technical requirements are more demanding than the standards. In particular, all plates must pass ultrasonic testing to guarantee internal soundness. Mechanical tests must also be performed per mother plate, while the standard only requires this testing per lot of 40t.

On top of this, the supplier must have received NF Acier certification - delivered by AFNOR. ArcelorMittal Gijón Heavy Plates belongs to the mills in Europe that possess this certification. ArcelorMittal Gijón is approved for most of the structural grades up to 80mm.

ArcelorMittal Europe delivered heavy plates to Victor Buyck Steel Construction, the largest steel fabricator in Belgium and one of the largest in Europe.