Page 9 - TunnelTalk Annual Review 2012

Long-distance undersea
highway for Norway
Peter Kenyon, TunnelTalk
From left: Fig 1. Alignment for 20km subsea tunnels; Fig 2. The undersea link will be let in four lots
Two subsea tunnels totalling 20km in length comprise the Ryfast highway project to link Stavanger with Strand in Norway. Approved by the Norwegian Government in May 2012, the estimated NOK5 billion (US$1 billion) dual carriageway road tunnels are to be financed partly by regional and national government sources, and mostly by toll income.
The project comprises two linked undersea tunnel sections (Fig 1):
• The 14.3km Solbakk tunnel linking
Solbakk and the ferry port at Tau in the Strand municipality, and the island of Hundwåg, via an alignment underthesmallislandofHidlewhere a ventilation shaft is planned. At its deepestpointitwillbe290mbelow sea level, with an average depth below the seabed of 50m, making it the deepest and the longest of Norway’s subsea tunnels.
• The second Hundvåg tunnel, at 5.7km, will link Hundwåg and the mainland city of Stavanger and will include an exit ramp at Buøy.
At Stavanger the subsea tunnels will connect with the new 3.9km road Eiganes tunnel on the main E-39 highway. With a construction estimate of NOK2 billion (US$330 million), the project is being funded 50-50 by tolls and central government.
Once all the tunnelling work is complete, ferry services that currently links Stavanger and Strand will cease.
Engineering design consultant Norconsult completed the alignment and planning studies in early 2012 and will be involved in the tendering process.
Anne-Merete Gilje, Construction Manager for the Ryfast project for Statens Vegwesen, the Norwegian Highways
Authority, told TunnelTalk that the undersea link between Stavanger and Tau will be constructed under four contract lots (E02, E03, E05 and E06), with the first starting at Solbakk in early Spring 2013 (Fig 2).
“The next contract will start from Hundvåg by early Summer 2013, with the third one for the Eiganestunnelen starting in Autumn 2013, and the last one, starting from Buøy in late Autumn 2013,” said Gilje.
The mega-project is scheduled for completion by the end of 2018.
All the tunnels will be two-lane twin- tube construction and based on drill+blast excavation. “We did consider TBM excavation but found drill+blast preferable. Our design consultant Norconsult is working on the final designs,” said Gilje.
construction of subsea highway tunnels, with more than 29 in operation and others in design and construction. The country’s first undersea road tunnel, the 2.6km Vardø link above the Arctic Circle, opened in 1981.
Norwegian Roads Authority (Statens
Vegwesen) Project Manager, Geir Tor
Espedal said: “Many questioned this
project but the thorough preparation work
that has been carried out has proven
decisive. The contracts for construction
References
Direct by Design
are so large that we expect considerable interest from foreign companies.”n
• •
Links across the waters: Straits Crossings conference report - TunnelTalk, January 2010 TBMs will excavate the Osol-Ski line -
www.TunnelTalk.com
TunnelTalk AnnuAl Review 2012
Norway is the world’s leader in TunnelTalk, Nov 2012
Mega dimensions of Orlovsky Project
A TBM of extraordinary 19.25m diameter, together with deep open-cut approaches through soft ground, and a double-deck, six-lane highway beneath the Neva River in St Petersburg are the mega proportions of the Orlovsky project in Russia. Dr Mikhael Ryjevski of the project’s Plato Engineering Group describes the technical scope of this proposed mega undertaking and Prof Fritz Grübl of PSP Engineering focuses on the design of the massive rings of the precast concrete segmental lining. The project remained on hold during 2012 while funding for the much-needed river crossing was being secured.
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