Norway Builds Sauda Fjord Hydro ProjectThe Sauda fjord hydro power project, an ambitious energy production infrastructure, is under construction in Rogaland county in south Norway, south of Bergen. The owner is Elkem Energi (85%) and Sunnhordland Kraftlag (15%). Norconsult is supervising the construction. Work started in May 2005 and is due for completion in April 2008. The project will cost NOK1.3 billion. Visit www.norconsult.noThe project involves the 2 km 18 sq m Slettedalselva tunnel built by Kruse Smith and the 2 km 25 sq m Dalvatn tunnel built by Veidekke. Visit www.kruse-smith.no and www.veidekke.noHowever, the biggest share of the scheme is Sønnå H, Sønnå L and Raundalen tunnels, 30 km in total, with cross sections ranging from 26 to 38 sq m, 55 sq m adits, intake shafts, surge shafts, pressure shafts and caverns, all built by Scandinavian Rock Group (SRG). The tunnelling and other construction work was split into two contracts, but SRG won both in May last year, valued at NOK700 million. This includes all civil engineering work. Visit www.srg.noMore specifically, the project includes the Maldal-Sagelva headrace tunnel, the Lingvang-Tengesdaln headrace tunnel, the Sønnå underground power house and the Sønnå tailrace tunnel. The main water inlet tunnel (Lingvang-Tengesdaln ) runs from Sønna power station to Dalvatnet lake and has 38 sq m section for a length of 9 km. The upper and side feeder tunnels, such as the long drive south to Lingvang, is of 25 sq m section. All are horseshoe shaped except where room is required for a 2 m-diameter ventilation duct in the crown and for operation of wheel-loader side-tipping buckets whilst mucking out. The geology is a combination of clayish schist and granite with a top layer of phyllites (thickness 0-300 m).A second construction site is the base for this work some five kilometres from Sauda along the Stroelva valley to the northeast. A short track off the main highway brings visitors to the Raundalen site where a portal begins a short access tunnel to an underground junction from which three faces are being driven northeast to the Dalvatnet lake, southeast to the Grimsvatnet area, and west to a junction with another planned tunnel and thence on to the Sønna power station caverns. Three of these five tunnel drives will tap intermediate water flows by means of shafts. Raise boring is planned to commence in 2006. Click here to view a presentation of the project with maps.SRG is using a fleet of several Atlas Copco drill rigs: one three-boom XL3C30 equipped with COP 3038 high-speed hydraulic drills, with possibly another delivered by now, two 353s, and one 282. When the project is at peak this year, there will be up to six drill rigs (two XL3C30s, two 353s, one 282 and one other rig to be used to tunnel 450 m per week in spring and early summer), a surface crawler for bench drilling in the main power station cavern and one or more raiseborers to 3.5 m diameter. All drill rigs use Atlas Copco Secoroc Magnum SR35 ballistic button bits. The explosives are Titan site-sensitised emulsions (SSE), together with 150 mm-long Dynamit primer cartridges and electronic detonation, supplied by Dyno Nobel. After blasting, the face is scaled with a blunt tool hydraulic hammer mounted on a Caterpillar 320B tracked excavator. Visit www.atlascopco.com, www.dynonobel.com and www.cat.comAt Raundalen, SRG operates an Atlas Copco Rocket Boomer XL3C with COP 3038 drills to work on three faces, although additional rigs are scheduled to help out with the work from this location. At the Raundalen site, a usual penetration rate of about 2 m/min using the COP3038 drills has been reported.From Sauda an Atlas Copco 353 drill rig had nearly completed the 800 m-long access drive to the new power station location in October. Another tunnel will be required for the tailrace to discharge water under the surface of the fjord. As the excavation of the main caverns commences, an Atlas Copco Rocket Boomer 282 will join the 353 to excavate the crown pilot bores for the caverns. Rig delivery was expected on 7th November, 2005.Speed is an essential ingredient of all operations. By October 2005, SRG had already completed two kilometres of tunnel from the Raundalen and Sauda sites. Breakthrough of the main tunnel to the Sauda power station caverns is scheduled for 1st August, 2006. The main system is due for completion in late 2007 with water flow in November. The power station will be producing power from early 2008. The six intermediate inlet points, mainly from streams and requiring diversion shafts, are likely to necessitate raise boring with mainly helicopter access to the uplands. The scheduling of these operations will need to be careful to avoid the excessive use of expensive helicopters, although the shaft site nearest to Raundalen will have track access.For support, Farex expansion bolts are installed, combined with shotcrete (35,000 bolts and 20,000 cu m of shotcrete). No permanent support is required in the design of the water tunnels.For muck haulage, two Häggloaders, three Volvo 220 trucks and a fleet of about 15 Mercedes 20 cu m 4x4 trucks are mobilised. Once the full tunnelling programme is under way from Raundalen and the power station caverns, the project will produce some 10 000 cu m of rock per week. The main spoil dump is about 3 km from the Sauda site. Visit www.gia.se/eng/prod_hagg_rail.htm and www.volvo.com. Click no/23. To read more, visit www.min-con.com 02/06.