Incremental Launching: How the Millau Viaduct Deck Was Positioned

Incremental Launching: How the Millau Viaduct Deck Was Positioned

The deck of the Millau Viaduct (France), the world's tallest bridge, was installed using incremental launching:

1. Fabrication: Steel deck segments (171 m long, 2,230 tons each) were welded together on the north approach viaduct.
2. Launching: Hydraulic jacks pushed the assembled deck forward, sliding it on temporary bearings atop the piers.
3. Repetition: New segments were added at the rear as the deck advanced span by span across the Tarn Valley.
4. Final Position: The 2,460 m deck was launched from one side only, reaching the south abutment in ~2 years.

Why Incremental Launching?

• Avoided massive temporary falsework in the deep, windy valley.
• Enabled high precision alignment.
• Accelerated construction; minimized environmental disruption.
• Demonstrated feasibility for long-span, high-piers bridges.

The Millau Viaduct remains a landmark achievement in bridge engineering.