Société des grands projets has awarded the contract to build the 7.4 km overhead section of line 18 of the Grand Paris Express, which will link Massy-Palaiseau to the future CEA Saint-Aubin station, to the consortium led by VINCI Construction Grands Projets. It is scheduled to come into service by 2026.
Located along the central section of line 18, which will serve 10 stations between Orly Airport station and Versailles, it will contribute to the development of the Plateau de Saclay, a top-tier centre of excellence featuring a high concentration of university campuses, prestigious higher education establishments and R&D centres.
The overhead section includes a 6.7 km viaduct. Building the viaduct in an urban area calls on VINCI Construction’s expertise in creating complex engineering structures. The 1,895 segments are prefabricated in the immediate vicinity of the worksite. We have chosen a deck that looks like an inverted “T” with an aeroplane wing profile to refine the edge of the viaduct and create an extremely light architectural design.
Our concrete formulations are designed to quickly build up strength while offering excellent workability. The segments will be placed with a launching gantry. This machine comprises two large metal beams that temporarily rest on the piers already in place, meaning that the gantry can assemble the segments in complete spans.
Self-compacting concrete has been used for the viaduct piers. This type of concrete is injected at the base of the formwork and is able to flow under its own weight, meaning that it can spread throughout the entire height of the formwork (12 metres high) without any need for vibration, which reduces the amount of arduous work for our operatives and produces an excellent quality finish.
A total of 201 piers measuring 9 metres high have been built, supported by 4 piles, with 13 piers on well foundations.
The site employs 400 people during peak activity, and the equivalent of 10 full-time jobs have been created on back-to-work schemes during the 30-month project. The VINCI Group has also set up its “Chantiers & Territoires Solidaires” endowment fund to support outreach projects promoting employment and social cohesion in the communities crossed by our Grand Paris Express worksites.
Client: Société des grands projets
Dodin Campenon Bernard
Chantiers Modernes Construction
Freyssinet (all subsidiaries of VINCI Construction)
Razel Bec (a Fayat Group subsidiary)
Project date: December 2020 to 2024
6.7 km viaduct comprising 1,895 segments
10,500 tons of reinforcements and 1,500 tons of prestressing
