Romanche Bridge at Séchilienne, France

A new bridge has been built at Séchilienne, about 30 km southeast of Grenoble, France, on a major alpine tourist route. The bridge over the Romanche River is in an uninhabited area and spans a relatively wide and stoney valley flanked by wooded slopes. While respecting the constraints of a standard construction budget, it was decided, in collaboration with the owner, to adopt an original bridge design for the site. After studying alternatives, a steel bridge was chosen. The challenge was to design an original structure capable of blending with a natural landscape. To provide sufficient clearance for the river, and to respect the preference for a longitudinal profile with a low backfill, it was decided to opt for a "top" supporting structure.