Swiss roads authority Office fédéral des routes (OFROU) is seeking a partner to design and construct a rehabilitation scheme for the safety tunnels at Mont Terri and Mont Russelin.
According to documents published in the Official Journal of the European Union, the 10 month project will involve strengthening of the rock mass around 7km of tunnels to ensure serviceability.
OFROU has identified 10 damaged zones within the Mont Terri gallery and a further six in the Mont Russelin tunnel. The authority has estimated that the work will require the installation of more than 400 rock bolts, over 3,500m2 of wire mesh and around 800m3 of shortcrete in addition to installation of framework, cast insitu concrete and excavation and reprofiling work.
The work must also be managed to ensure the operations of the tunnels is not interrupted and work around the underground rock laboratory at Mont Terri where geotechnical experiments are undertaken within the rock mass, which is also being extended next summer.
Bids for the work must be submitted by 9 October and the work is expected to start in May 2019.