Tender documents are currently being prepared for the 7.8km subsea Eiksund road tunnel, which will go out in May 2004, for a projected construction start of August 2004.
The tunnel forms part of the US$114M Eiksund link that will connect the Norwegian mainland to the island of Gurskøy, which has a population of 22,000. Also included in the project is the construction of two other tunnels totalling 1.8km, a 405m bridge and 4.9km of road.
Believed to be the deepest road tunnel in the world, the single tube tunnel will run 47m under the bed of a 240m deep fjord and is expected to present several challenges to the engineers.
Water ingress from the fjord is thought to present the greatest possible difficulty. Engineers will pre-grout up to 30m ahead of the face, before drilling and blasting through the gneiss.
The 7,765m long tunnel, with a diameter of 8.5m, will drop down from Steinnes to beneath the fjord, at a gradient of 7.6%. The tunnel will then increase to 11.5m in diameter (up to three lanes from two), before heading up to Eika at a gradient of 9.6%.
The other two tunnels between Steinnes and the E39 highway, will be more straightforward. At 1,160m and 630m, both will have two lanes and a diameter of 8.5m, and be constructed using drill and blast.
The Norwegian Road Authority (Statens Vegvesen) has designed the tunnel in-house, with consulting services provided by Norwegian consultants Norconsult.
Related Files
Eiksund link
