• Shoring walls consisting of Steel Piles, Ground Anchors and Shotcrete to retain the excavation of up to 7m depth.
• 391 Steel Piles (5950 m), 199 Ground Anchors (5400 m) and 1500 m² Shotcrete.
• Ring-Bit system with Pilot bit used for Piles and Double Rotary Head system used for Anchor drilling.
The project
The Follo Line Ski project is part of the new high-speed railway line between Oslo and Ski. After completion in 2022, Ski will have a modern transport hub with three platforms and a completely renewed station area.
To build the tracks north of the station a permanent retaining wall had to be built.
The challenge
- Difficult soil conditions including sensitive soft clay, moraine layers, large blocks and bedrock.
- Extraordinary welding detail requirements for piles and anchor beams.
- Complex site logistics and limited working space.
- Presence of fully operational rail tracks along the wall.
- Sequencing works to maximize the production (up to 3 drilling rigs concurrently on site).
The solution
- Double Rotary Head system to minimize disturbance of surrounding soil.
- Welding plant to prefabricate the pile casings and anchor beams.
- Spare equipment to keep the tight time schedule.
Project facts
Owner(s)
Bane NOR
Keller business unit(s)
Keller Geoteknikk AS
Keller Grundläggning AB
Keller Grundbau GesmBH
Main contractor(s)
OHL Norge
Engineer(s)
Project Manager - Vidal Alcon
email: vidal.alcon@ohla-norge.no