E18 Grenland tunnel

E18 Grenland tunel, Porsgrunn, NOR

  • Main client: Nye Veier
  • Client: Eiffage
  • Contractor: Metrostav Norge AS
  • Construction period: 01/2023 – 08/2024
  • Price: 436 000 627 NOK excluding VAT, ca 959,2 mil. CZK

Project description

The Grenland tunnel is a part of the E18 Langangen-Rugtvedt project, which is 17 kilometres long and includes a 4-lane highway, bridges, and tunnels. The project constitutes a bypass around the city of Porsgrunn, on the E18 highway between Oslo and Kristiansand. The Grenland tunnel itself has a total length of 5,2 km and is being excavated using the Kjørholt portal in the south, the Herregårdsbekken portal in the north, and two access ramps approximately in the middle of the tunnel.

Metrostav Norge AS is excavating a part of the double-tube Grenland tunnel. From the Kjørholt portal, the excavated length is 2x 1,7 km, and from the Herregårdsbekken portal, it is 2x 1,4 km.

Project data

Tunnel:  4 tunnel faces (in total 6 164 m)
Tunnel profile:  T10,5 ca 80 m2
Excavated volume:  517 097 m3
Shotcrete:  19100 m3
Bolts, rock bolts: 31100 pcs
Grouting: 1.600.000 kg


Challenges / Specifics of the project

  • high requirements for work and environmental safety, and quality
  • an extensive project
  • coordination with the contractors of other sections of the tunnel
  • predicted need for extensive grouting