Line 15 South of the Grand Paris Express

To the south of the capital, Line 15 South of the Grand Paris Express links Pont de Sèvres to Noisy-Champs, crossing 22 municipalities and four departments to create a fully underground metropolitan arc. Bouygues Travaux Publics is acting as consortium leader for two major batches: T2A, between Villejuif–Louis Aragon and Créteil-L’Échat, and T3A, between Pont de Sèvres and Fort d’Issy-Vanves-Clamart. These sections include 10.8 kilometres of tunnel and six underground stations, serving as gateways to the future metropolitan districts. Their construction takes place in highly constrained urban environments, requiring a high degree of precision to integrate the structures without disrupting existing infrastructure.

The construction of stations and tunnels on Line 15 South presents a major geotechnical challenge. The heterogeneous soils of the Île-de-France region require advanced construction methods, including ground freezing, which was used at the Vert-de-Maisons and Issy RER stations. This cutting-edge technique involves increasing the mechanical strength and impermeability of the ground by freezing the water naturally present, in order to secure the excavations. On batch T3B, the Fort d’Issy-Vanves-Clamart station, the first station of the Grand Paris Express, showcases our expertise in civil engineering in constrained environments: its perimeter walls are made of diaphragm walls, and its upper reinforced concrete slab, weighing 7,000 tonnes, was constructed beforehand and slid into its final position in just three hours.