Ceneri Base Tunnel

The Ceneri Base Tunnel in Ticino is part of the New Rail Link through the Alps (NEAT). The base tunnel has two single-track tubes and passes under Monte Ceneri over a distance of 15.4 kilometres.

That makes the tunnel the third-largest tunnel construction project in Switzerland, after the Lötschberg and Gotthard base tunnels. In addition to the actual tunnel, an inclined access gallery with a length of 2, 7 kilometres was built at Sigirino using a tunnel boring machine with a diameter of 10,7 metres.

Amberg supported the project in various phases. In addition to consulting during the preparation of the construction project and the tendering process, the services also included bid comparison and support during the award of contracts. Amberg was also entrusted with the implementation project planning and the complex construction management. The engineers were thus able to transfer much of the know-how gained from the construction of the Gotthard Base Tunnel to the construction of the Ceneri.

The heterogeneous alpine geology, mainly consisting of gneisses and amphibolites, made high demands on the accompanying seismic exploration, which was used by Amberg among others in the main fault "Linea Valcolla". The fault was characterised by poor rock quality, deformations and an overburden of 600 metres.

The low overburden when crossing under a motorway at the north portal required many demanding construction operations, including jet grouting, pipe shielding, securing and lining. The GeoMonitoring services of Amberg were used here to monitor the construction process. In the case of the south portal, the focus of the work in the urban area was on reducing vibrations.