• Installation of sheet piles in close proximity to live railway traffic.

• Execution of almost 3,500m of jet grouting columns (column diameters up to 2.2m).

• For supporting structures, 323,9mm micropiles were installed near existing overhead power lines. 

K144

The project

In summer 2021, Keller resumed works in Oslo Central Station as a part of the Folloline Project. In order to allow for safe excavation works, Keller executed a range of geotechnical products to protect the existing railway structures.Part of the works had to be executed from the existing tunnel with the limited headroom of 5.5m.

The challenge

  • Tight time schedule to finish within the set shutdown period.
  • Sheet piling works to be performed close to tracks and overhead line.
  • Working simultaneously with different geotechnical products.
  • Part of jet grouting works were performed in a tunnel with less than 5.5m headroom.

The solution

  • Keller managed to complete the works before the deadline. Day and night shifts were implemented in order to meet the schedule requirements.
  • To mitigate any potential delay with latent ground conditions, Movax and Vibro hammer were utilized to drive the sheet piles into the ground.

Project facts

Owner(s)

Bane NOR

Keller business unit(s)

Keller Geoteknikk AS
Keller Grundbau
Keller Grundläggning

Main contractor(s)

HAB Construction AS

Engineer(s)

Project Manager - Gard Mogen

Oslo S (Summer Shutdown 2021)