Customer case

Pumping station 40 - Luleå

February 08, 2023 6 min read

Night view of the building’s perforated sheet metal façade with integrated illumination and illustrations of the work at the SSAB Luleå site.

Case details

Product RD® pile walls

Country Sweden

Company Hercules Grundläggning

Industry Building structures and infrastructure

Luleå is a region in growth. Its existing water and waste system is now 60-100 years old and in great need of upgrading to deal with the growing population. By 2040, the population is expected to reach 100 000 inhabitants. “Östre länken” was initiated in 2014 and will be ready in 2026. It consists of 4 new pumping stations and 20 km of water pipes with a diameter of up to 2 meters. This is Luleå Municipality’s biggest construction project ever and has an estimated price tag of up to SEK 2bn. There are already 70 pumping stations in the area to ensure the transportation of fresh water from the Lule River to end users and then transport the used water back to Uddebo wastewater treatment plant.

Case details

Product RD® pile walls

Country Sweden

Company Hercules Grundläggning

Industry Building structures and infrastructure

Day view of the building’s copper coloured façade. Architect: a och d arkitektkontor, through M. Nilsson, M. Wikström & N. Granljung

NCC are the main contractor for the pumping station in Arontorpsviken, which is located very close to a lake. Because of this, NCC wanted to make a vertical shaft to avoid a big excavation pit and chose to use an SSAB RD pile wall for this purpose. The wall has a very high bending moment resistance for its size, it can be installed gently in all soil conditions and provides a water tight solution. The project has been called “Pumping station 40” and will be decorated with illustrations carved in steel that represent SSAB’s presence in the region with its steel mill. The NCC contract is estimated to be 475 million SEK.

The RD pile wall was delivered in 20 meter long elements in RD400/12.5 pile size. This length was used to avoid splicing the piles at the site and was why Hercules Grundläggning used a very big piling rig capable of handling such long piles. A total of 850 piles were installed to form 100 m x 100 m square with 4,300 m of piles amounting to more than 550 tonnes of steel. The piles, spirally welded steel pipes fitted with connectors, were mainly made at SSAB Oulainen Works in Finland. The unique RM/RF connectors were robot welded onto the piles.

The work progressed very well and the installation of the pile walls progressed ahead of schedule. A lot of time was saved by SSAB's special delivery of 20 m piles, because of which there was no need to carry out further welding on the site. Utilizing the S550J2H steel grade in the pile wall also added enough capacity to avoid larger pile sizes or increased anchor points and excavation steps.

Water and clay contributed to messy conditions above ground while drilling RD pile wall

The soil conditions meant easy drilling, but water and clay contributed to messy conditions above ground.

In particular, we are very happy with the timely delivery to the site during the installation phase to ensure progress, and without the site being filled with piles before use.

Robert Kangasmaa, Hercules

Hercules’s construction site where Destia Oy is responsible for the drilling of the RD pile wall. The rig is equipped with a long drill mast to handle the 20-m long piles.

To counteract the earth pressure, the RD pile wall was supported by inner steel struts at two levels. The struts were made of steel pipes delivered from SSAB in sizes of 660x14.2 mm and 508x12.5 mm. This resulted in three excavation phases during the construction. The soil consisted of sand and silt with a basal moraine. Although Hercules had no trouble drilling through the soil strata, the site naturally got a bit muddy during drilling.