months of work

Construction, parallel to the existing tunnel, of a safety tunnel to evacuate users and provide ventilation, decommissioning of ventilation chambers in the existing tunnel, construction of ducts and connecting lines between the existing tunnel and safety tunnel, decommissioning of the 1,373 concrete ventilation chambers (width 7m, length 5m, weight 20 T), decontamination in the specific washing line, on-site crushing/grinding and recycling of materials.