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).
During the construction of the Vienna underground line 2 extensive dewatering works with approx. 270 wells and approx. six million pumping hours were required. An electronic monitoring and control system made the measure safe.
New U-railway line in the center of Dortmund will replace the existing overground running tram.
Below the protected monument, the „Kaufhof“ building at Kö in the heart of Dusseldorf, a tunnel with a connecting platform to the existing railway station „Heinrich-Heine-Allee” is built, which is exactly situated in the middle of the new “Wehrhahn” line.
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.