WTC 2004

The Bothnia railway link – improving transportationin northern Scandinavia

Bo I. Karlsson *

Botniabanan AB, Ornskoldsvik, Sweden

On the 27th of November 1997, an agreement for the construction of the Bothnia Line was entered into between the

Swedish government and four municipalities (Kramfors, Ornskoldsvik, Nordmaling and Umea) in the counties of

Vasternorrland and Vasterbotten. The Bothnia Line, a 190 km, single-track, high-speed rail link running from

Kramfors in the south to Umea in the north, is one of Scandinavia’s largest railway projects in modern times. As part

of the agreement, a company, Botniabanan AB, was set up to be in charge of designing and building the line.The project’s goal is the improvement of communications and freight transport in the north of Scandinavia. The

present main railway, which runs inland and was built early in the 20th century, is nearing its capacity ceiling. A fully

developed Bothnia Line will vastly improve passenger and goods transport to and from northern Scandinavia.

Amongst the features of the new, 190 km, single-track rail link are 22 passing places, 140 bridges and around 39 km

of rock tunnels. The project is split into 130 major contracts. The largest of these is for the 32 km line between Of-

fersjon and Bjallstaan. Work started in August 1999 and is scheduled for completion in 2008. The total estimated cost

is SEK 15 billion.

The project’s 39 km of rock tunnels includes 15 rail tunnels totalling 24.4 km in length. Service tunnels account forthe remaining 14.6 km. Four of the service tunnels are being built parallel to the larger rail tunnels – Askott (3.3 km),

Overview of the Bothnia Line between Kramfors and Umea.

* Tunnel Manager. Tel.: +46-660-294-824; fax: +46-660-29-48-20.

E-mail address: bo.karlsson@botniabanan.se (B.I. Karlsson).

doi:10.1016/j.tust.2004.02.039

Tunnelling and Underground Space Technology 19 (2004) 420–421

www.elsevier.com/locate/tust

Tunnelling andUnderground SpaceTechnologyincorporating Trenchless

Technology Research

Namntall (6.0 km), Bjornbole (5.2 km) and Varvsberg (2.1 km). The service tunnels for Askott and Varvsberg are 2.3

and 1.1 km long, respectively. The total volume of the rock tunnels is around 2.2 million cubic metres.

The tunnels are being excavated through Scandinavian gneiss/granite formations and meta-greywacke. The rock is

generally of good quality with typical Q-values (Barton et al., 1974) of between 1 and 100. Grouted in rock bolts and

fibre-reinforced shotcrete are being employed as the standard forms of rock reinforcement. Continuous pre-injection isbeing used in the construction of all tunnels.

Two separate stretches (118 and 102 m) of the 1,450 m long Stranneberg tunnel had little or no rock burden. In these

cases, reinforcement was provided by, respectively, jet grouting and soil freezing.

Final sealing and rock reinforcement is provided by concrete cladding. Jet grouted sections have a 65 cm lining for

the floor and a 55 cm lining for roof and walls. The figures for soil frozen sections are 70 and 65 cm, respectively.

So far (late July 2003), four tunnels, with a combined length of 4.4 km, have been completed.

Keywords: Continuous pre-injection; Granite; Jet grouting; Soil freezing

421S. Kemmochi et al. / Tunnelling and Underground Space Technology 19 (2004) 420–421