Tunnel de la Grand'Mare


The tunnel, 1.5 km long spread over 2 tubes, has undergone a complete overhaul in order to meet the highest standards of safety and functionality.

The teams from Eiffage Génie Civil (leader) and Eiffage Énergie Systèmes played a central role in bringing this remarkable project to fruition.

This major renovation includes several essential aspects to improve the safety and functionality of the tunnel.
It involves the creation of seven new emergency exits, complementary to the three existing ones, as well as the modernization of the ventilation system, lighting and safety devices.

  • Renewal of lighting: New lighting is introduced to improve visibility and safety throughout the tunnel.
  • Power Renewal: Power infrastructure is upgraded for increased efficiency and reduced energy consumption.
  • Renewal of ventilation and smoke extraction from the tunnel: More efficient accelerator fans are installed.
  • Airflow Control: A crucial measure to regulate air velocity in the event of a fire with congested traffic.
  • Integration of ventilation in 7 new emergency exits: “Branches” strategically positioned between the tubes ensure the safety of users.
  • Upgrade of Centralized Technical Management (CTM): A sophisticated system is put in place to centrally monitor and manage all tunnel operations.