Piling completed on Norway’s longest railway bridge
By Leila Steed25 March 2021
Specialistic sub-contractor Aarsleff Ground Engineering has completed the installation of foundation piles, for what is said will be the longest railway bridge in Norway.
Stretching across the River Vorma, the new 836-metre-long Minnevika Bridge is being built north of Oslo in the south east of the country and is part of a massive expansion of the country’s railway system.
The company, a subsidiary of Danish firm Per Aarsleff, used a Liebherr LRH 600 piling rig with a fixed leader system to install a total of 20 pier shafts with 280 friction piles driven into the ground.
Dennis Jensen, senior project manager at Aarsleff Ground Engineering, said, “The design challenge lay in achieving the ground bearing capacity because the rock lies so deep, therefore inclined piles were required. The project is situated in a inland lake, which makes the transportation of large machines and large materials much more difficult.”
Jensen added, “We have to drive in the piles with an inclination of up to 1:5 and the hammer size was an important requirement both for Aarsleff and also the capacity of the LRH 600. Liebherr was the only supplier that could fulfil our technical requirements with a short notice and deliver a carrier machine and leader as a complete package.”
Aarsleff also used a Liebherr duty cycle crawler crane HS 895 HD as the carrier machine. Positioned on a barge, it was used to drive half the piles into the bed of the River Vorma.
“The stability of the piling rig on the barge is surprising. Even with strong currents we can position the piles within the tolerances specified for the project in water 12-14 m deep,” Jensen said.
Aarsleff completed the installation of the 29-tonne steel pipes, which have a foundation length of 58m and a diameter of 1016mm, almost eight months ahead of schedule despite the disruption caused by the Coronavirus pandemic.
The piles have to ‘rest’ for two years before the Minnevika Bridge can be used for rail traffic.
Construction of the bridge, which is due to open in the autumn of 2023, is being carried out by a consortium that includes Porr Nordic Construction (PNC). In addition to the bridge, PNC will also build three shorter bridges, a tunnel and a 4.5km double-track rail line running between Eidsvoll North and Langset.
PNC was contracted to undertake the works by the state-owned organisation Bane NOR, which is responsible for Norway’s national railway infrastructure.