Hochtief Austrian tunnel contract

German-based contractor Hochtief has signed a €140 million joint venture agreement with Implenia Österreich to build the Granitz Valley tunnel chain in Austria.

It forms a key development of works on the 130km high-speed Koralm railway system connecting the southern states of Carinthia and Styria.
The project will involve construction of an approximate 6km section of the new line and is scheduled to be built over the next five years.

Running between Lavant Valley and Jaun Valley, the Granitz valley tunnel chain comprises the Deutsch Grutschen Tunnel (2.6 km), the 600m long Granitz Valley enclosure, and the Langer Berg Tunnel (2.9 km).
As with the 32.9km Koralm Tunnel, which has involved cement supplied by Cemex, it will be built as a double-tube tunnel system.

According to Hochtief, the contract for the shell construction of the tunnel chain entails cut-and-cover building at the portals and in the Granitz Valley, as well as landscaping and accompanying hydraulic engineering at the Granitz Valley enclosure.

The overall Koralm railway scheme, which links the cities of Gratz and Klagenfurt, is planned for completion in 2023.