Projekt D15, Bybanen, Løvstakken tunnel, Bergen, Norway


Hordaland Fylkeskommune represented by the company BYBANEN Utbygging

Main contractor

Marti Tunnel AG, Switzerland represented by branch office Marti Tunnel NUF

Construction period

January 2018 – December 2022

Description of main objects:

  • Double track tram tunnel with cross passages to walk/bike tunnel (as escape tunnel)
  • Walk/bike tunnel as escape tunnel
  • Portal with roundabout at the top
  • Natural stone walls
  • Pump station and emergency reservoir
  • Technical rooms in the tunnel
  • Landfilling and access tunnels to depots
  • Tram depots

Description of tunnel excavation:

  • main double tract tram tunnel, L= ca. 2900m, profile T9.5 (ca. 10m width and 6m height), excavation volume ca. 233 300 m3
  • escape walk&bike tunnel, L= ca. 2900m, profile T7.5 (ca. 7,0m width and free height ca. 4,6m), excavation volume ca. 169 700 m3 (biking path with 3,5m width, walking path with 2,5m width)
  • 6 pcs of escape corridors, L= ca. 18m of each EC, profile T4.0 + 5 niches in connection to escape corridors. Total volume ca. 8500 m3
  • 2 technical rooms, excavation volume ca. 1500 m3
  • Pumping station and emergency reservoir, total excavation volume ca. 5000 m3
  • 2 pcs of caverns as train depots (L= ca. 130m, width ca. 17 m, height ca. 8 m. A= ca. 140m2)
  • Access tunnel to tunnel depots, L= ca. 450m, cross section vary from ca. 55m2 – 180m2
  • Equipment of tunnels (watter&frost lining, technology, trolley-lines etc.)

Technology of construction: (norwegian tunneling method) + systematic probe-drilling and grouting works if required