Luxembourg Builds Grouft TunnelWith a population of 465,000 and an area of 2,586 sq km, the Grand Duchy of Luxembourg is a tiny country landlocked by Belgium, France and Germany. It is among the wealthiest countries in the world, with a GDP per capita of USD55,100.The Grouft tunnel is under construction as part of the Route du Nord (A7) between Luxembourg City and Ettelbruck. The EUR171,226,416 project, commissioned by the Ministry of public works, is for the construction of a twin-bore 2,966 m-long tunnel between the Heeschdrëfferbierg plateau at the south and Alzette valley near Lorentzweiler in the north. The tunnel is being built by a joint venture called Tunnel Grouft, established by Wayss & Freytag, Max Boegl, Galere, Tralux and Felix Giorgetti. The design studies have been achieved by Luxconsult and Lombardi. The construction management is ensured by TR-Engineering and Geos. Safety and health coordination has been commissioned to Schroeder and Secolux. Visit www.pch.public.lu/projets/tunnel_grouft and www.wf-ingbau.de/de/corecapabilities/projects/tunnel_grouft.phpThe tunnel consists of a two-lane downhill tube and a three-lane uphill tube. The carriageway width is 7 m and 10.5 m respectively. From Alzette valley, the tunnel is characterised by an average gradient of 4.5%. There are two excavated profiles, horseshoe shape (69.5 to 111.7 sq m) or invert (99 to 164.1 sq m). At the portals, the distance between the two bores is 20.4 m minimum to gradually increase on a distance of approx. 700 m at the south and 800 m at the north to reach a maximum distance of 41.55 m. The cover above the tunnel varies between 3-4 m at the portals to a maximum of 80 m. Ten 30-35 sq m cross connections at intervals of 250-300 metres will be constructed between the bores. The alignment traverses under forests and fields. The tunnel section varies between 90 sq m and 160 sq m.The geology is mainly fractured sandstone, poor marls, silt and some gypsum. There are four faces excavated simultaneously from each end of both tubes. The excavation method varies between traditional methods (hammer and bucket) in the rock with soft to medium resistance and drilling and blasting in hard rock. It is changing almost daily. A fleet of four Liebherr R934B excavators equipped with backhoe buckets, ripper buckets, rotary heads and hydraulic breakers are used for mechanical excavation. For drill and blast, the machinery comprises of one Atlas Copco semi-automatic WL3 C Rocket Boomer, two Atlas Copco L2 Cs and two Robodrill two-arm drill rigs with basket. All are equipped for dry drilling. The explosives are supplied by Orica Germany (pumped emulsion, non-electric detonators). Visit www.atlascopco.com, www.robodrill-sa.com and www.orica-germany.comFor muck haulage, four modified Liebherr L564T wheeled loaders are being used together with 14 Kaelble dumpers. Visit www.liebherr.com and www.kaelble.comSupport and lining required by the client consist of Swellex bolts, shotcrete, HEB 220 and HEB 160 steel arches or lattice girders with 3 or 4 bars. The shotcrete is reinforced with fibres (40 kg/cu m) supplied by Trefil Arbed (1,500 tonnes) and is sprayed by five MEYCO Potenza units. Visit www.swellex.com, www.meyco-equipment.ch and www.trefilarbed.comExcavation officially started in August 2005 and should be completed within 29 months, followed by lining, roadworks and equipment. As of 6th December, 2005, 160 m and 93 m has been driven from the northern portal and 280 m and 173 m from southern portal. Total completion is scheduled within 54 months (mid-2009). Click lu/13. 50-51/05.