Project of the Year incl. Renovation (up to €50M)
FEDRO’s Tunnel Renovation Method – renovation of a non-reinforced primary lining using night shifts while keeping all traffic lanes open during the day
This project consists in the removal of part of primary lining, installation of drainage & sealing systems, final lining with self-compacting concrete, construction of verges incl. drainage, renewal of road surface, installation of electrical equipment.
To secure the availability and usability of the motorway network, the Federal Roads Office (FEDRO) developed new solutions for the renovation of road tunnels while keeping them open to traffic, and initiated an innovative project. Completely replacing the primary lining could not be regarded as a standard solution because the secondary lining could not guarantee stability and the demolition work could endanger road users. The solution that was ultimately considered was to partially remove the primary lining,install drainage and sealing systems and then construct a new final lining.
The stability of the weakened arch could be secured using temporary rock bolts, and traffic diversions would only take place at night when work was being carried out in the tunnel.
The new arch of self-compacting concrete in tunnel T3 was constructed in a single step and is designed solely to provide the necessary stability. To maintain two-lane traffic during the day, aspecial tunnel formwork had to be conceived. For this project, two sealing systems were tested and compared: conventional synthetic sealing membranes and a sprayed sealing system.