« Borne Romaine » Tunnel (South East of France)

The ‘Borne Romaine’ section of the A8 motorway between Nice and La Turbie (in the Alpes-Maritimes region, south-east of France) is located on an unstable slope. The mitigating measures implemented and the diversion of one carriageway on the side towards the mountain have turned out to be insufficient to ensure the long-term stability of the structures. That’s why the motorway management company ESCOTA decided to build a tunnel in the slope to accommodate one carriageway and thus move the whole road system out of the unstable zone.

The works, carried out under project management by EGIS Tunnels, were contracted at end-2013 to the consortium CAMPENON BERNARD TP Côte d’Azur – GTM Sud – SOLETANCHE-BACHY-TUNNELS – EUROVIA. TERRASOL has then been entrusted by the consortium with the whole detailed design (supports, linings, structures, utilities), with contribution from BMCI (subsidiary of SETEC TPI) for the structural aspects.

The structures comprise a tunnel 800 m long excavated in a good quality limestone massif, a safety tunnel 80 m long between the mid-point of the main tunnel and the open air, and the portal structures and equipment (architectural walls, tunnel substation, fire-fighting water basin and water recovery basin).

Terrasol’s achievements:

  • Detailed design (support, lining, utilities, …)
Characteristics
PERIOD :  2014-2015
Client : ESCOTA
Project Manager : Egis Tunnels
Main specifications :  

  • 750 m length (traditional excavation method)
  • Diameter: 12 m
  • Safety gallery: 80 m
  • Amount of works: 36.5 M€

Download the brochure

To go further


OPQIBI qualifications

Resources

Activities