Laabmayr projects

Laabmayr has a proud history of successful tunnel projects both in mountainous areas and urban environments, always able to solve complex problems in underground works and produce on time. Just a few examples are provided below.

Project 1

Site supervision
Semmering Base Tunnel, Austria

Under two hours by train from Vienna to Graz, thanks to the Semmering Base Tunnel, the heart of the Südbahn upgrade in Austria.

The alignment “Pfaffensattel” was chosen to be constructed, for much of its length passing a long way to the south of the existing Semmering Railway in the Fischbacher Alps. The two bores are 40 to 70 m apart and connected by cross-passages with an average offset of 500 m. The tunnel has an average gradient of 0.84 %.

Particularly challenging are the geological and hydrogeological conditions. These often require round-the-clock availability and rapid response in the design.

The design speed is 230 km/h. Extensive design and supervision of injection measures (ground improvement, water management) are necessary. The swelling of anhydrite must be taken into account in the excavation and support measures and for the secondary lining.

Project 2

Vienna Metro lot U2-17,

Lot U2-17 comprises the extension of Metro link U2 from the Altes Rathaus station to Matzleinsdorferplatz.


  • Structures: TBM drives, emergency exits at Reinprechtsdorferstraße, Kaunitzgasse and Augustinplatz.
  • Design: Alignment optimisation, consents design, tender design, preparation of tender documents, tender evaluation, detail design and as-built records, including design coordination in all phases.

The entire project includes two 3.3km-long running tunnels and the stations Matzleinsdorferplatz, Reinprechtsdorferstraße, Pilgramgasse and Neubaugasse.

The new route also includes three crossovers, which also serve as emergency exits, and a run-around at Matzleinsdorf.

The run-around and the station tunnels are to be constructed by NATM. Prior to the tunnel drives, the groundwater level will be drawn down using bored wells. The running tunnels will be constructed using a earth-pressure-balance TBM.

Project 3

New build railway Wendlingen-Ulm,
Tunnel Albaufstieg, Germany

The Albaufstieg section is the central component of the 59.6km-long Deutsche Bahn (DB – Germany Railways) new build railway between Wendlingen and Ulm. The route passes the entire length of the mountain range Schwäbische Alb on its northwest-southeast alignment from Wendlingen near Stuttgart to Ulm.

The topology dictates that five tunnels of total length 30.4 km, 17 railway bridges and 20 road bridges are constructed to create the railway.The heart of this section is the twin-bore, 8,806m-long Boßler Tunnel and 4,847m-long Steinbühl Tunnel.

According to the safety concept, cross-passages are to be constructed at 500 m centres. The Boßler and Steinbühl Tunnels will have 17 and 9 cross-passages respectively. The Boßler Tunnel will be partially constructed from a secondary access adit, which is 960 m long and will be backfilled after completion of construction.