Customer: Gotthard AlpTransit AG
Construction period: 12.2001 – 02.2014
Location: Canton Ticino
The Gotthard base tunnel is the heart of NEAT (Neue Eisenbahn Alpen Transversale – New Railway Alp Traverse) with a total length of 57 km. The contract is divided into five section from north to south: contract section Erstfeld: 7.38 km, contract section Amsteg: 11.35 km, contract section Sedrun: 8.33 km, contract section Faido: 13.05 km, contract section Bodio: 16.56 km. The tunnel consists of two single-lane tubes with a cross-section of 65 m2. It is designed for a speed of 240 km/h. At each third of the tunnel is an emergency stop with railway equipment. The company Consorzio TAT will construct the section Bodio and Faido and the emergency stop Faido.
The tunnel of both contract sections mainly goes through the Penninische gneiss zone, Leventiner gneiss and Lucomagno gneiss. In part there are 2,000 m of rock above the tunnel with mountain temperatures of up to 40 degrees Celsius. The only interference zone worth mentioning is the so-called “Piora Mulde” with rock pulverized to what is called Zuckerdolomit (Dolomite Alp sugar).
Method of construction
Tunnel drills (open gripper machines) will be used to excavate the single-lane tunnel. It will be secured with steel-fibre shotcrete, construction steel grids, anchors and where necessary with tunnel-construction arches. The tunnel will be sealed off 3,000 m behind the tunnelling and a non-reinforced concrete interior shell of 30 to 40 cm will be installed. Excavations and support of the emergency stop Faido and the transverse connections between the single-lane tunnels will be constructed according to the NATM (New Austrian Tunnelling Method) using blasting when the tunnels are being completed. It will have a total length of about 14 km.