Gotthard Base Tunnel, Bodio Bypass
The Gotthard Base Tunnel, a project of the century, consists of two parallel single-track tubes, each 57 km long and represents the core of the Alp Transit route of the Swiss Federal Railways on the Gotthard axis. At the southern portal of the 16.5 km long Bodio part-section, the longest for the Gotthard Base Tunnel, there is an area of soft ground. In order to guarantee quick access to the underground assembly area for the tunnel boring machine in hard rock, the soft ground zone was bypassed by the approximately 1.2 km long Bodio Bypass Tunnel. Subsequently, the base tunnel drive will be executed until the tunnel boring machine for the main contract section is ready to be assembled. According to the current construction schedule, it is assumed this will be after about 2 to 3 km. There is predominantly gneiss and granite along the route of the bypass tunnel and very little ingressing water is expected. The tunnel was driven by drill+blast, predominantly using a full excavation, and was secured by shotcrete. The vaulted ceiling of the bypass tunnel was not finished. Only the base invert is lined with in-situ concrete.
- Country: Switzerland
- Region: Canton Ticino
- Tunnel utilization: Traffic
- Type of utilization: Main-line rail
- Client: AlpTransit San Gottardo
- Consulting Engineer: EWE Zurich, Lombardi SA
- Contractor: Bilfinger BergerAG, Batigroup AG, Frutiger AG
- Main construction method: Trenchless
- Type of excavation: Drill-and-blast
- Lining: Shotcrete
- No. of tubes: 1
- Tunnel total length: 1,184 m
- Cross-section: 51 to 70 m²
- Contract Volume: € 29 million
- Construction start/end: 2000 to 2002