UDK 01 - Rock tunnel and open stretches

  • EPC contract based on NTK 15
  • Notification in September 2018
  • Contract to be signed in August 2019
  • Construction time August 2019 to March 2023

Rock tunnel

The rock tunnel will be a blasted single pipe, double track tunnel with blasted cross-section of approx. 123 m² and a free space area of approx. 93 m² once fully built. It will be approx. 6 km long measured from the Danvik face to the Gulliksrud face at Skoger. 

It will be sealed using systematic preinjection to secure water balance in the area and safeguard the environment. The tunnel will be stabilised with bolts, spray concrete, etc. for a projected service life of 100 years. Water and frost protection will be achieved using a membrane covered with contact-cast vault construction.

The tunnel will be driven from two cross tunnels and from Gulliksrud to the south. The two cross tunnels, at Austadveien and Danserud, will act as evacuation tunnels once the tunnel is in use. Parallel evacuation tunnels will be built linked to the cross tunnels in parts of the main tunnel.

In addition, two dedicated evacuation tunnels will be built, one to an existing escape tunnel from the Strømsås tunnel and one out to the surface at Gunnerud, ensuring emergency exits for every 1000 m. The evacuation tunnels will be 25 m2, while the cross tunnels will have a larger cross section (60 m2) as they will be used for access during driving of the railway tunnel.

Surface section in Skoger

New tracks will be laid for projected train speeds of 200 kph approximately 1600 m long, south of the tunnel portal at Gulliksrud. The new track crosses existing tracks at two points, and lies closer to the E18 than the current line over a stretch of approx. 500 m. A railway bridge, crossing the E18, will be built.

Gundesølina road bridge will have to be rebuilt over the new track, because the route will meet the road abutment and the headroom under the bridge is insufficient. 

Main volumes rock tunnel

Blasting of the main and cross tunnels

938,000 m3

Waterproofing and frostproofing Concrete vault

169,000 m2

Waterproofing and frostproofing Sealing membrane

40,000 m2

Spray concrete sealing layer

25,000 m3

Spray concrete retaining arches

9,300 m

Reinforcement layer of crushed stone aggregate

39,000 m3

 

Surface section in Skoger

Concrete

8,400 m3

Reinforcement

1,300 tonnes

Tension reinforcement

15,150 mN

Excavation

75,000 m3

Frost insulation and filling with cellular glass or expanded clay

20,000 m3

Reinforcement layer of crushed stone aggregate

18,000 m3

Noise barrier

4,300 m2

 

Tracks and other railway engineering installations are not included in UDK 01.