Route du Nord – Stafelter Tunnel

The Stafelter Tunnel is located in the north of Luxembourg in the community of Waldhaff and is the last of three tunnels driven by mining means for the North Road ("Route du Nord"). The North Road links the capital of Luxembourg with the towns of Mersch, Colmar-Berg and Ettelbruck lying in the north of the Grand Duchy firstly to relieve Luxembourg City from through traffic in this direction and secondly to more effectively open up the economic regions in the north of the country. The Stafelter Tunnel connects the Haeschtreferbierg Plateau with the end of the A 7 motorway near WaIdhaff. It consists of two parallel running, two-lane tubes with a horse shoe shaped cross-section. At its south portal the tube towards Luxembourg City is to be provided with a three-lane enlargement area so that it can accommodate a deceleration lane. The tunnel passes beneath the Grünewald close to the surface with overburdens ranging from 4 to 16 m. Over a length of around 800 m the tube leading to Luxembourg City runs beneath the CR125 regional highway to Walferdange. The tunnel tubes are driven in Luxembourg sandstone, a formation of regularly fissured, carbonatic, cemented sands with interspersing beds of limestone by a combined excavator and drill+blast operation. Owing to the route close to the surface karst-like cavities filled with sand and alternating, sandy zones with low strengths can be prevalent. The two tunnel tubes are linked to each other by 6 cross-passages. The cross-passage in the middle of the tunnel in the vicinity of a fault zone is to be developed as an emergency exit with a 17 m high evacuation shaft. Driving operations are undertaken from the south portal. Supporting is generally carried out by a steel fibre reinforced shotcrete outer shell with arch supports and an anchoring system. In fault zones excavation work proceeds protected by a pipe umbrella. Parallel to these driving operations the tunnel is produced over a distance of some 200 m at the north portal by cut-and-cover. The inner support mainly consists of an unreinforced inner shell which is 30 cm t hick with umbrella seal.

Country: Luxembourg
Region: Luxembourg
Tunnel utilization: Traffic
Type of utilization: Road Tunnel
Client: Grand Duchy of Luxembourg, Administration des Ponts et Chaussees
Consulting Engineer: Luxconsult (design), Müller+Hereth (design)
Contractor: Wayss & Freytag Ingenieurbau AG, Max Bögl Bauunternehmung GmbH & Co. KG, Galere S.A., Felix Giorgetti S.a.r.l., Tralux S.a.r.l.
Main construction method: Trenchless
Type of excavation: Excavator/Drill-and-blast
No. of tubes: 2
Tunnel total length: 2 x 1,850 m (total), 200 m (cut-and-cover), 6 cross-passages, 1 evacuation shaft (h = 17 m)
Cross-section: 76 to 115 m²
Contract Volume: approx. 88 mill. euros net
Construction start/end: December 14th, 2008 t ill August 31st, 2012
Opening: 2014