Le Day Viaduct

The double-track bridge is used by TGV Lyria services between Paris and Lausanne on the Lausanne–Vallorbe line of the RER Vaud (Réseau express régional vaudois) and the line from Vallorbe to Le Pont in the Vallée de Joux with its extension to Le Brassus.

Extensive research resulted in its reconstruction as a massive arch bridge as the cheapest solution.

Subsequently, the existing superstructure was carried by smaller supporting arches based on the pillars.

The slightly overhanging superstructure now has a total width of 8.4 m. The arches are made of natural stone because concrete from the local gravel would not have had sufficient strength and the SBB wanted to avoid a contrast with the existing pillars.

Only the parts of the pillars above the footbridge, the supporting arches and the remaining superstructure were built in stamped concrete and then covered with natural stone.