Skanska has been tasked by the National Road Administration Stockholm to build the Värtan Interchange (NL52), which is one of Norra länken’s larger subprojects.
NL52 is a large and complicated bridge design with many different parts. The actual construction site is squeezed in between a harbor, a railway, a bridge, Lidingövägen, Fortum and TV4. A lot will be taking place in an area that is approximately 900 x 500 meters in size.
Road traffic, freight transportation and a host of other factors also need to be considered. Lidingövägen, which is used daily by over 40,000 vehicles, will be kept open throughout the project. That means we will need to redirect the road several times. In addition, we will need to take the Värtabanan railway line into consideration, which is used to transport goods to and from Värtahamnen harbor and must be functional throughout the construction period.
Passing through the area is the Ropsten subway line as well as ground conduits to Stockholm Vatten’s waterworks and the energy company Fortum’s facilities. Certain conduits can be avoided with the help of maps, but for many conduits we will quite simply have to dig up due to the vast number. Our task includes laying new conduits; a total of five kilometers of conduits will be laid within the small project area.
“It is an incredibly exciting and eventful project,” says Linus Lindström, Project Engineer.
“The organization here is considerable compared with many other projects, we have about 150 people on site. It is exciting to follow developments in the area as well. Some 10,000 new housing units, space for 30,000 office workers and a new shopping center will be built. The harbor will be renovated and Norra Djurgårdsstaden is situated just on the other side of Fortum.”
Our work on Norra länken is part of the development of the harbor area. Housing construction has already started and the first stages will be ready at about the same time as the bridge construction.
Before the actual construction of the road could begin, we performed ground reinforcement measures in the form of pipe-laying and foundation work. Preparatory work for the traffic rerouting and concrete work has also been conducted.
After that followed excavation and pile-driving. The ground consists of an old, clay seafloor, which means that we needed to use extra piles, approximately 27,500 meters were used in total.
The excavation work involved approximately 16,000 cubic meters of rock excavation and 130,000 cubic meters of soil excavation. Pictured another way, that means the amount of rock that was removed was sufficient to fill 85 three-room apartments that are 75 square meters in size and the soil that was stripped would have filled almost 700 three-room apartments of the same size.
Rock has been crushed on site for reuse in road construction thus reducing haulage costs for removing rock and bringing road material to the site.
Ground conditions were different from our initial expectations and have thus posed a challenge. However, we have solved this challenge and will keep to the timetable.
Traffic in the middle of the worksite
The project is subject to the restraints imposed by the four reroutings of the traffic on Lidingövägen, which sees 40,000 vehicles a day. Each rerouting will enable us to have access to a new area to continue our work.
“Traffic rerouting has functioned very smoothly. We have traffic going through the middle of the worksite but it has still functioned incredibly well,” says Mats Alexanderson, Project Manager.
About 150 people are working on NL52, which is the only major bridge project for Norra länken.
Winner of two environmental awards
In 2011, NL52 was awarded Skanska Sweden’s worksite health and safety award and the Swedish Transport Administration’s work environment prize. Furthermore, we have worked more than 700,000 hours without one single accident resulting in absence, which demonstrates that we have earned these awards. Safety permeates everything we do.
The project in figures
Overall amounts, approximate:
• 27,500 meters of piling
• 50,000 meters of LC pillars
• 5,500 square meters of sheeting
• 16,000 cubic meters of rock excavation
• 130,000 cubic meters of soil excavation
• 900 meter pipe-laying DN>1000
• 4,400 meter pipe-laying DN <1000
• 71,500 meters of formwork
• 6,000 tons of reinforcement
• 48,000 cubic meters of concrete
• 220 bridge bearings
• 550 meters of bridge joints
• 130,000 square meters of surfacing