A11 Karawanken Tunnel, second bore,
Austria-Slovenia border

This project was realized in cooperation of IGT and the engineering office laabmayr.

The western bore of the Karawanken Tunnel was opened for two-way traffic in 1991 and is managed jointly by the Austrian (ASFINAG) and Slovenian (DARS) highway agencies. the existing bore is 7870 m long and has no emergency escapes.

IGT’s scope includes options studies, tunnel concept design consents design, tender design, detail design, on site geotechnical engineer, landfill planning, design and construction coordination and a BIM pilot project.

Based on the results of the options study, the decision was taken to add a second bore to create twin tunnels. The second bore will be 7840 m long and constructed as a mined tunnel.

Particular challenges are the difficult geotechnical conditions and the high groundwater volumes expected to be encountered during the tunnel drive. As part of the new build, the north portal service building is to be extended and the underground service rooms are to be brought into line with modern requirements. The portal areas are to be designed in coordination with the bridge designers. A suitable area for infill for disposal of excavated material is proposed in the Kanin area. The geology, tunnel and service building were included in a BIM pilot project.