Improving safety in the Puymorens Tunnel

19 June 2013 - New contracts - France

Charged by ASF (VINCI Autoroutes) with improving safety in the Puymorens Tunnel (south-west France) and bringing it up to current standards, the design and implementation consortium composed of Freyssinet (Soletanche Freyssinet/VINCI Construction), Cegelec Mobility (VINCI Energies GSS), and Bonnard et Gardel has appointed Soletanche Bachy Tunnels (Soletanche Freyssinet) to undertake the excavation and retaining works for 9 safety shelters and 11 sloping evacuation tunnels. The mixed geology of the tunnel (hard granite and soft schist) will require the use of different techniques (mechanised excavation, excavation using explosives) depending on the position of the shelters and evacuation tunnels along the 4,800 m length of this tunnel. Scheduled to be carried out in one season, these works will involve closing the tunnel from 15 April to 15 November 2013. The works started on 8 April 2013. Concrete, a VINCI subsidiary operating under the Continuum brand, is in charge of the justification studies and securing the tunnel against fire. A software programme has been developed to size and optimize the thickness and extent of the fire protection plates.