The construction of tunnels using conventional construction methods has always been a challenge to every engineer. Here, the engineer’s most important task is the evaluation of the geology and the selection of the right means of securing the excavation face until final completion of the inner lining. Wayss & Freytag already rose to this challenge in 1905 when building a railway tunnel using the conventional tunnelling method in Wasserburg/Inn in gompholite (Nagelfluh) and gravel.
The range of conventional tunnelling reaches from soft rock tunnelling (e. g. a metro tunnel in Munich gravel) and tunnelling in compressed air (e. g. Ostbahnhof metro station in Munich in Tertiary formations below groundwater) to classic drill and blast drives (e. g. Rennsteig Tunnel on the A 71 motorway, which, with a length of 8 km, is the longest motorway tunnel in Germany).
The Roppen tunnel between Innsbruck and Landeck in Austria was made safer by the construction of the second tube. The 5,069 meter long tunnel was driven conventionally.
A milestone for the Koralm railway line from Graz to Klagenfurt: the double-track tunnel with a length of 1.7 km forms the centrepiece of this construction section.
Due to an advantageous layout of tunnel portal and tunnel excavator is was possible to do without shunting bays and laborious shunting during the construction of the single-track railway tunnel.
During extension of the Pyhrn motorway, the Gleinalm Tunnel is provided with a second tube. This makes the motorway safer, since there will be no oncoming traffic in the tunnel.