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Gotthard Base Tunnel, Contract 360, Section Sedrun

The Sedrun contract section represents the core of the 57 km long Gotthard Base Tunnel, which will enable high-speed trains to cross the Alps on a flat trajectory. The biggest challenge posed by the Sedrun part-section with its 2 roughly 6.5 km long tunnel tubes, is to penetrate very tricky geological zones and supplying material for and removing it from the 4 drives at a depth of 800 m via a shaft. This was facilitated by increasing the diameter of a second shaft from 4 to 7 m and immediately setting up a conveyor system suitable for tackling heavy loads. In this way, it is possible to separate the transportation of heavy machinery and materials from the removal of the excavated muck. In addition, site operations are also enhanced in terms of safety and economy. At the foot of these shafts, 2 tunnel tubes are being driven conventionally both to the north and south by means of drill+blast and partially using an excavator. The excavation is largely undertaken with overburden of around 2,000 m in relatively unstable rock formed by the "Tavetsch intermediate massif" and the "Urseren Gavera zone" thus placing high demands on tunnelling. Owing to the high convergences expected in this area, an enlarged excavated cross-section is to be produced. A rock bolt system and specially designed support arches, which are installed to accept rock movements, will be installed for supporting purposes. The permanent reinforced shotcrete lining will first be placed once these movements fade. More favourable driving conditions can only be anticipated over the final approx. 2.7 km of the southern section, which predominantly constitutes gneiss rock with better soil properties. The permanent lining will be made of in situ concrete mostly without reinforcement under the protection of an umbrella seal. One of the 57 km long Gotthard Base Tunnel's 2 Multi-Function Stations is also to be set up in the Sedrun part-section. It consists of various caverns, enlargements and connecting galleries, which are required to house the necessary underground installations such as the concrete mixing plant and logistics equipment during the construction phase. When operational, the Multi-Function Station will serve as an emergency stop and house technical equipment.


  • Country: Switzerland
  • Region: Canton Grisons
  • Tunnel utilization: Traffic
  • Type of utilization: Main-line rail
  • Client: Alp Transit Gotthard AG
  • Consulting Engineer: IG Gotthard Basistunnel Süd
  • Contractor: Batigroup AG, Bilfinger Berger AG, Frutiger AG, Pizzarotti S.p.A.
  • Main construction method: Trenchless
  • Type of excavation: Drill-and-blast
  • Lining: Concrete formwork?
  • No. of tubes: 2
  • Tunnel total length: 2 x 6.5 km
  • Cross-section: Main tubes: up to 135 m²; Multi-Function Station: up to 260 m²
  • Contract Volume: € 750 million
  • Construction start/end: August 2002 to August 2011
  • Opening: 2014