Zurichberg Tunnel

The Zurichberg Tunnel connects the Stadelhofen and Stettbach Stations, both in Zurich. The Swiss Federal Railways (SBB), both own and run the Zurich Rapid Transit System. The first part of the tunnel (about 500 m), near Stadelhofen, is situated in soft ground with a shallow overburden, dense population and traffic. The tunneling was carried out from an access shaft by jet grouting, heading and bench, and support from shotcrete reinforced with wire mesh. The second part (4,355 m) is situated completely in rock (sandstone, marl, siltstone and limestone). The tunneling was executed with a tunnel boring machine (TBM) at an average advance rate of 13.5 m per day. The lining consisting of precast elements placed directly behind the TBM in the shield, was reinforced later by cast-in-place concrete. The third part (700 m) is situated in soft ground in a rural area. It was completely constructed by the cut-and-cover technique with sheet piling where necessary. The construction includes the Stettbach Station with a tramway terminal constructed on the back filling.