Skanska and Veidekke Entreprenor have won two tunnel contracts on the new Lysaker-Sandvika rail link, near Oslo, being built by Norwegian National Rail Administration (Jernbaneverket).
Meanwhile, in the west of the country, the public roads authority (NPRA), has awarded a 2.3km tunnel contract to Mika and called for tenders on a total of 2.4km of tunnels for the approach roads to Hardanger suspension bridge.
Outside Oslo, Skanska Norge will build about 800m of single bore tunnel for the twin-track rail line as part of Lot LS-04 on Jernbaneverket’s new Lysaker and Sandvika link. The US$83M (excl. VAT) contract also includes construction of a link tunnel to join the existing line, and a 60m access tunnel. Having just commenced, the contract is due to complete mid-2011.
Farther to the east, on Lot LS-02, Veidekke starts this month on the US$61M contract to build a 420m access tunnel to Skallum station and then drive the 108m2 single bore 800m east and then west. Construction is scheduled to end in Q3-‘10.
Jernbaneverket is building a new 6.7km long rail link between Lysaker and Sandvika as part of an line upgrade between Skoyen and Asker. The new link between Lysaker and Sandvika calls for a total of 5.5km of single bore, the lines entering tunnel some 500m outside of each station.
Drill and blast was elected as the most economic construction method during analyses by Multiconsult in 2005 in comparison to other tunnel plans (twin bores, etc) and excavation techniques, including TBM. The analyses also considered environmental factors as well as weighing reliability, availability, maintenance and safety needs.
In west Norway, contractor Mika has just won a US$23M contract from NPRA to drill and blast the single bore Fatlaberg tunnel plus 250m of sideroads and 1km of new road. The cross-section of the tube is a standard T8.5, which is 8.5m wide at two-lane road level. Construction is due end Q3-‘08.
The regional division of NPRA has also called for bids to drive 2.4km of single bore road tunnel through gneiss for the approaches to the new Hardanger suspension bridge. With T8.5 profiles, minimum height of 4.6m and and maximum grades of 5%, there will be four tunnels in total – 1100m, 800m and two 250m long tubes.
Excavation by drill and blast is due to begin by July and complete by October 2008.
The tunnels were designed by Bergen-based Opticonsult to NPRA plans.
