Infrastructure

AlpTransit Gotthard Base Tunnel, Switzerland

AlpTransit Gotthard Base Tunnel, Switzerland

Switzerland

Project facts

Project Type: 57 km long, double-tube high-speed railway tunnel

Client: AlpTransit Gotthard AG

Project Period: 1994 - 2016

Services: Environment: environmental impact assessments, landscape planning, environmental construction supervision, project assistance; Tunnelling: studies, preliminary design, tender design and construction design, tender process, tender evaluation, final design

: Electromechanics: design, tender process for tunnel and railway facilities; Rail traffic: technical coordination and organisational support for the interdisciplinary Transtec Gotthard joint venture

: Ventilation/safety: aerodynamic and thermodynamic studies, design of ventilation for construction and operation, design and tender process for operational and cross passage ventilation

Providing a fast railway link between northern and southern Europe through Switzerland, the Gotthard Base Tunnel will form the core of the new transalpine railway axis, AlpTransit.

It will consist of twin single track high speed rail tunnels running 57 km between Erstfeld and Bodio. The maximum overburden is over 2 300 m. Pöyry' services in this major project include environmental services, tunnelling, electromechanics, rail traffic and ventilation/safety.

The southern three design lots of the Gotthard Base Tunnel cover the most technically challenging sections of the alignment. This southern section of the tunnel includes the intermediate adits at Sedrun (800 m vertical shaft) and Faido (2 700 m inclined gallery) and the multifunction stations where these adits meet the base tunnel.

The Sedrun lot will be excavated by conventional means, the Faido and Bodio lots by open TBM's. The lining consists of shotcrete rock support with an inner lining of cast in-situ concrete.

The southern part of the tunnel runs to the north predominantly in gneiss and granite of the Gotthard massive, and to the south in the Pennine gneiss zone. These relatively straightforward zones are intersected by the Tavetsch Inter-mediate Massif, Urseren Garvera zone and the Piora syncline, all of which are particularly demanding with soft rocks under high pressure.