Vedeggio-Cassarate Road Tunnel - Civil works

The Tunnel Vedeggio-Cassarate (L=ca.2'630 m) links the Valley of the Vedeggio River to the Valley of the Cassarate River northern of the city of Lugano in Switzerland. The project is a single bidirectional tunnel. The cross section has an intermediate slab, which separates the traffic space from the exhaust air aspiration channel. A parallel safety tunnel (Ø 4.5 m) was excavated on the south side of the main tunnel (30 m). Every 300 m, there are bypasses alternately for pedestrians and vehicles linking both tunnels. The first 2’350 m from the portal Vedeggio were excavated by D&B through the crystalline rock of the south alpine formations. The following ca. 200 m up to the portal Cassarate were excavated in loose material composed of quaternary heterogeneous glacial-river deposits in different consolidation states, with several independent artesian water tables characterized by pressures up to 2 bars.In the loose ground stretch the ground had to be previously consolidated with jet grouting. Where this was not possible from the surface the ground was consolidated in advance of the tunnel face with jet grouting and fore polling. In the middle of the tunnel is located a cavern equipped with two ventilators for the aspiration of the fume in case of fire and electromechanical devices serving the whole tunnel. The exhausted air is then expelled through a 60 m long tunnel and a 100 m high vertical shaft to the surface. The tunnel crosses twice the new Ceneri Base tunnel of the Gotthard main railway line with only few meters overburden (5 m and nearly 2 m).
Country
Switzerland
Reference location
Lugano
Final client
Dipartimento del Territorio Canton Ticino
Is Consortium
True
Start of works date
1/1/2004
End of works date
7/28/2012
Start of services date
1/1/1997
End of services date
6/30/2014
Services
Civil designs; Construction supervision; General planning / management