Keller has announced that it has been awarded a major contract to undertake work on construction of a new railway line in Austria.
The £23.1M deal covers jet grouting, bored piling and anchor works for a 32.8km rail tunnel that Strabag is constructing on the Koralm railway line between Graz and Klagenfurt.
The 9.93m diameter twin bore tunnels where launched in 2012 through a 60m deep shaft and are being driven westwards through complex geology with an overburden of up to 1.25km. Strabag is using two Aker Wirth telescopic shield tunnel boring machines.
The tunnel alignment takes the construction through partially weathered slate formed mostly from gneiss-schist and unweathered shales of mica gneiss with local fault zones. The tunnel will also pass through the 4km long Lavanttaler fault system.
Keller’s work on the scheme to improve the ground above and below the tunnel bore will take two years to complete and is expected to start in the second quarter of this year.
The tunnel is expected to open for rail traffic in 2023.