Keller installed about 390 pcs. of Ø406 and Ø273 mm pipes for a pile wall at the base station area of Fornebubanen. Keller also installed 48 pcs. of strand anchors and whaler beams for the pile wall.
The project
Implenia Norge AS has been contracted by Fornebubanen to carry out additional works near the Fornebubanen base station and the tunnel entrance. Before the project could progress to the next phase, a pile wall had to be installed to accommodate the upcoming works and the future buildings planned for this location.
The challenge
The main challenge in this project was executing the works above an existing tunnel, in close proximity to a steep cliff, and under difficult ground conditions with large boulders. These factors were also the reason why sheet piles were not selected as the preferred method.
The solution
The chosen solution focused strongly on HSE, particularly on minimizing risks near the steep cliff. This was achieved by drilling steel bolts into the ground and installing a solid safety fence, while ground pressure from the rigs was reduced through the use of limited working areas and large load-bearing steel plates. The drilling challenges were managed with heavy drilling equipment, including our Comacchio MC40 drilling rig.