Koralm Tunnel Liner, Agru Austria
At 32.9 km, the Koralm Tunnel is one of the longest in the world.

By AGRU – With a total length of 130 km, the Koralm railway, anchored by the extraordinary Koralm Tunnel, links the Austrian cities of Graz and Klagenfurt. It is an important part of the Baltic-Adriatic Corridor, which connects the Baltic and Adriatic Seas. As such, the Koralm railway is a major transport infrastructure project, not only for Austria but Europe as a whole.
The new high-speed railway link has reduced the Graz-Klagenfurt travel time from currently 3 hr to approximately 1 hr.
Without any doubt the centerpiece of the new construction is the Koralm Tunnel. With a length of 32.9 km, it will be one of the longest railway tunnels in the world. It consists of two parallel tunnels that are linked with crossways every 500 m.

Koralm Tunnel, Agru Austria
Roughly 12,000 m of waterstops were installed to protect Section KAT 1, a 2.3 km long portion that also utilizes 132,000 m2 of geomembrane protection.

At the east entrance of the tunnel, Section KAT 1 has a length of 2.3 km. This part of the tunnel has been constructed using the new Austrian tunnel method (drill and blast). In order to protect the tunnel from groundwater, approximately 132,000 m² of AGRUFLEX tunnel liners have been installed. Additionally, 12,000 m of water stop profiles have been used.
Lining of this portion of the Koralm Tunnel took place  in 2012 and 2013. KAT 1 was successfully completed on time in November 2013.

  • Two tunnels running parallel and connected every 500 m
  • Each tunnel contains a single railway track
  • Length: 32.9 km
  • Austria’s longest railway tunnel
  • Depth: The tunnels run as low as 1,250 m below ground
  • Full operational date is planned for 2022

AGRUFLEX Tunnel Liner

The AGRUFLEX tunnel lining system offers excellent chemical resistance and flexibility. It utilizes a white signal layer. In contrast to PVC, AGRUFLEX is completely free from plasticisers, environmentally friendly in production, and comfortable to install.
The geomembrane installed in the Koralm Tunnel fulfills the new Austrian Tunnel Sealing Guideline (Österreichische Bautechnik Vereinigung – published 2012). A strict procedure which includes continuous testing ensures high quality during production. External testing has confirmed the quality.
Learn more about AGRU Kunststofftechnik GmbH, tunnel lining, and other applications at www.agru.at.