RD® piles from SSAB crucial to Skanska’s project to rebuild Slussen

“From the outset, we were grateful that SSAB’s RD pile retaining walls existed on the market because, without them, this whole project would have taken much longer time,” says Marzena Burzec-Burzynska, Project Manager, Skanska.

Originally built in 1642 as a lock between Södermalm and the Old Town in Stockholm, Slussen is one of the Swedish capital’s main traffic hubs, catering to 30,000 motorists, 26,000 cyclists, 23,000 pedestrians and 270,000 subway passengers every day. Since the 1600s, Slussen has been rebuilt several times. The current redevelopment began in 2016 because the last Slussen, built in the 1930s, was worn out. Constructed using the so-called Franki piling system and with porous concrete that water can penetrate, sections of the old Slussen had sunk up to 20 centimeters, while parts were crumbling and rusting. It was decided that the entire structure had to be demolished and rebuilt from scratch.

Attractive meeting spot

Once completed, the new Slussen will cater to fewer cars, while offering enhanced solutions for pedestrians, cyclists and public transport. Stockholm City is also seeking to turn it into an attractive meeting spot, complete with a city park and new market squares. Last but not least, the redevelopment project will secure clean drinking water from Lake Mälaren for two million habitants.

The project started in 2016 and is well on its way. So far, SSAB has delivered 117,000 meters of piles, corresponding to 10,700 tons of steel, to Skanska and Slussen since the project began.

RD^® piles from SSAB play a crucial part

Marzena Burzec-Burzynska explains that SSAB’s RD^® pile retaining walls have an especially crucial part to play in this challenging project.

“RD walls are used instead of sheet pile driving when the ground conditions demand it or when we want to reduce the impact on the area, because drilling causes fewer vibrations,” she explains, adding: “Since we are working so close to Stockholm’s Old Town and subway system, choosing this method was of vital importance.”

The area around Slussen has a complex geology, with depths of up to 70 meters to bedrock. It is made up of various layers of the Stockholm Ridge and many centuries of filling material. As a result, different types of piles are being used at Slussen depending on ground conditions.

RD^® pile walls are suitable in challenging conditions

Based on RD^® piles and installed by drilling, RD^® pile retaining walls are suitable for retaining wall structures in difficult ground conditions. The RD^® pile retaining wall works extremely well in retaining wall structures that are under not only horizontal loads but also vertical loads.

“RD walls also allow us to construct a new temporary shoreline, in order to excavate deep holes that allow the actual construction work to take place. Since this work is being carried out in the center of the city where we don’t have much space, the RD walls allow us to do what we need to do within the limited area available,” continues Marzena Burzec-Burzynska.

Smooth collaboration

When Skanska began planning the Slussen project, SSAB’s RD® pile retaining walls was a known solution on the market. After the project start, Marzena Burzec-Burzynska and her colleagues have been satisfied with the deliveries.

“Our collaboration with SSAB is very good and has always been smooth,” she says. “The delivery times are reliable and flexible, and we receive a high-quality, competitively priced product with all the necessary documentation.”

Another important consideration is sustainability.

“We need to make sure what we are installing has as low an impact on the environment as possible. This is important for Skanska and we value what SSAB is doing to make their products more sustainable,” says Marzena Burzec-Burzynska, concluding: “A major company like SSAB investing in green solutions has the potential to make a big difference for the whole of Sweden.”