The Mont Blanc Tunnel has reopened after a 15-week closure for reconstruction of sections of the tunnel vault.
Two 300m sections underwent what French operator ATMB described as “experimental renovation” to address wear from water infiltration and to waterproof the areas. The two sections were located approximately 2km and 8km from the tunnel entrance in France.
The work involved removing equipment, such as cameras, signs and incident detection; installing containment airlocks before planing 5-10cm from the vault; injecting micro-mortar at the back of the vault and re-sealing; and reinstating all tunnel equipment.
Lessons learned from this work will determine the renovation of a further 600m next year. ATMB said the aim was to identify the best operating procedure, including the technology used and the time required.
“The Mont Blanc Tunnel is more than 60 years old. It is now the first of the major European tunnels to undertake deep renovation work on its structure. In addition to the regular maintenance carried out during maintenance nights, this exceptional infrastructure naturally enters a period when it requires large-scale civil engineering work. This work is necessary to guarantee the sustainability of the work over the long term,” ATMB said.
In 2023, Eiffage’s VES (Ventilation des Espaces Souterrains) specialists replaced the tunnel’s fan accelerators.
