Soletanche Bachy France: The Livernan Tunnel project is nearing completion after a year of work!

This project, entrusted by SNCF Réseau to the Soletanche Bachy consortium (lead contractor), Colas Rail RTS, and Ferrotract, aims to increase the tunnel’s clearance to allow the passage of specific convoys carrying semi-trailers.

The project, which began in December 2023, was carried out in two distinct phases, interrupted during the 2024 Olympic Games. The work was carried out track by track, with significant railway constraints, including the need to work on a single track with restricted hours.

The work involved creating a shotcrete shell over 64 meters, with or without stiffeners, and replacing metal voussoirs with reticulated arches on an existing beam. More than 271 meters were subject to occasional openings, using reinforced shotcrete voussoirs or dry rescinding. The consortium was able to try new methods such as hydrodemolition for coating removal, significantly reducing the dust caused by milling.

The main challenge of the project was working on an adjacent active track with ARF (Authorization to Engage in Railway Risk Zones) in single-track mode during 5.5-hour time slots, including 3 hours simultaneously. For this, the day teams worked from two work trains, specially equipped with telescopic protective screens and equipment adapted to the confined environment, such as horizontal silos and shorter drilling slides.

The Livernan Tunnel project is a success for the Soletanche Bachy, Colas Rail RTS, and Ferrotract consortium. This project also marks the beginning of a series of four tunnels to be refurbished on the Paris-Bordeaux line, with the next project planned for the Plans Tunnel. The consortium is already preparing for this new phase, drawing on the experience and successes achieved on the Livernan Tunnel.