Important projects and works

Renewing of road deck, a civil engineering challenge in the service of safety

Les équipes du Tunnel du Mont Blanc ont complété au printemps 2024 la dernière phase de réhabilitation de la dalle de roulement dans la partie centrale du tunnel sur une longueur de 240 mètres.
La rénovation a consisté en le remplacement des éléments de dalle qui supportent la chaussée, au-dessous de laquelle se trouvent les gaines de ventilation.
Le procédé technique adopté a permis – grâce à une organisation complexe – de travailler prioritairement la nuit et de restituer le tunnel à la circulation des véhicules chaque matin, tout en garantissant la sécurité des équipes de chantier et des usagers du tunnel.
Ce dispositif avait été testé en 2018. Le retour d’expérience a permis de définir le mode de renouvellement de la dalle le plus adéquat pour les travaux suivants, entre 2021 et 2024.
Grâce à cette intervention, la dalle de roulement du Tunnel du Mont Blanc a été entièrement rénovée sur une longueur totale d’environ 1.700 mètres dans la zone centrale de l’ouvrage.
Si l’on considère l’ensemble du projet de réhabilitation de la dalle de roulement, réalisé entre 2018 et 2024 sur environ 1.700 mètres linéaires de tunnel, l’investissement est de 60 millions d’euros, financés à parts égales par les deux sociétés concessionnaires du tunnel, ATMB et son homologue italienne SITMB.
The images below refer to the work carried out in 2018.

Tunnel vault reconstruction works: the first trial construction site will be operational from the 2nd of September to the 16th of December 2024, and will require full closure of the tunnel

In 2024, the first trial construction site for renovation of the tunnel vault over two 300 metre-long sections will open. This project, initially planned for 2023, was pushed back for a year by an Italian and French intergovernmental commission to ensure good connections between Italy and France following the landslide on the A43 in Maurienne (F).
In order for the works to be carried out, the MONT BLANC TUNNEL WILL BE COMPLETELY CLOSED TO TRAFFIC FROM 5:00 P.M. ON MONDAY 2 SEPTEMBER UNTIL 5:00 P.M. ON MONDAY 16 DECEMBER 2024.
This period (autumn) has been jointly identified by the Valle d’Aosta and Haute-Savoie prefectures as having the least impact on tourism, in particular for light vehicles, the primary users of the tunnel (68% of traffic in 2023) and the economy between the two regions.
The type of works, the geometric characteristics of the tunnel, the need to dismantle all the technological plant equipment in the work zones, and worker safety requirements means that vehicular transit is not possible under any circumstances, even temporarily, throughout the duration of the works.
The Mont Blanc Tunnel, which is over 60 years old, is the first major tunnel in Europe to undergo major structural renovation, with major civil engineering works on the road deck and vault.
For the future renovation of the tunnel vault, two experimental phases of work will be carried out in 2024 and 2025 which will allow the best method with which to move forward to be identified.
TMB-GEIE, alongside the companies and workers involved in the project, are fully committed to meeting the schedule of works in order to limit the period of closure to the planned timetable.
The two concessionary companies SITMB and ATMB will continue to work with the authorities of the two countries to offer the best alternative road traffic links between Italy and France during these major works.

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