In the past Wayss & Freytag was significantly involved in the development of mechanized tunnelling techniques. For example, they initiated the support of the tunnel face by means of a bentonite suspension and air-cushion. With the so-called “slurry shield” this technique was brought to operational maturity. Wayss & Freytag is a pioneer of this technique and has in the meantime driven more than 150 km of tunnel using slurry shields. In addition, more than 80 km of tunnel were driven using earth pressure balance shields and 30 km using hard rock TBMs.
Tunnel construction in a very restricted area requires a multitude of construction methods to carry out the structure with as little interference as possible with the neighbourhood.
Length: approx. 7,400 m 2 drives: West 3,230 m and East 3,8700 m in length Internal diameter: 3.60 m External diameter: 4,50 m bore diameter approx. 4.80 m
2.5 km long underground railway line in a double-tube underground track system for the North-East-Line (NEL) in Singapore with two stations, two underground passages and a flyover.
Greatly varying geology required different driving methods during the construction of the Uetliberg Tunnel in Switzerland. The 4.4 km long road tunnel connects the Birmensdorf bypass with the existing national road Zurich-Chur.