Varberg Tunnel contract awarded1 October 2019
Sweden – Implenia has been awarded the design and construct contract for the twin-track rail link between Varberg and Hamra. The project notably includes tunnelled work between the city of Varberg.
Located on the country’s west coast, the project is worth SEK 3.5bn (USD 360M). This work includes the planning and construction of a 2.8km drill-and-blast tunnel, a 450m cut-and-cover tunnel, a 1.3km cutting, several bridges, a new railway station and a total of 2.7km of track, plus a freight train station. The main tunnel will have a cross-section of 75m2, the service tunnel ca. 20m2 with cross-tunnels of varying cross-sections.
Implenia is designing the tunnel without an inner lining and is using rock bolts for ground support and pressure grouting for water sealing.
Of the main challenges on the project, a spokesperson for Implenia said, “There are areas of low rock cover in the northern part of the tunnel, under the town center of Varberg. The rock in this area is charnockite, a local and very rare form of granite. Driving through these parts of the tunnel will be the most challenging. Further we have very tight requirements on water leakage and will thus be faced with a challenge in sealing the tunnel.”
The construction work is due to take around six years, during which time the existing railway line will continue to operate. From 2024, trains should be running on the new tracks beneath Varberg’s city centre.
In summer 2018, Trafikverket, the Swedish Transport Administration, awarded the Implenia a commission worth approximately SEK 200M (USD 20.37M) for the initial planning and preparation works.
The spokesperson added, “Thanks to [our] early involvement and the collaborative contract structure, the company was able to optimise planning, preparation and construction methods in close partnership with the customer. This has put us in an excellent position to execute the second phase of the project and the contract for the detailed planning and construction work.”