Tunnels and underground structures
Due to Slovenia’s varied topography, there are a considerable number of tunnels on the national road motorway and rail network, all of which have to be regularly inspected. A considerable number of tunnels will also be built on the new Divača – Koper railway line. In the field of tunnel construction ZAG performs the following works:
- Geological and geomechanical investigations,
- Static and dynamic stability analyses,
- External control of the quality of construction of tunnels,
- External control of the quality of prestressed and passive geotechnical anchors,
- Monitoring of tunnels during their construction and later exploitation,
- Periodical and main inspections of tunnels.

References
External control of the following tunnels:
The Karavanke motorway tunnel – repair works, the Karavanke railway tunnel – repair works, and the Golovec, V Zideh, Trojane, Podmilj, Jasovnik, Kastelec, Dekani, Barnica, Tabor, Šentvid, Leščevje, and Cenkova motorway tunnels, and the Markovec tunnel
DARS 1998 – 2014
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Study of the possibilities of construction of underground structures in Slovenia (2000-2002)
ARAO 2000 – 2002
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Study of the possibilities of the underground excavation of natural stone in Slovenia
ARAO 1998 – 2005
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Repair of several sections of the Karavanke motorway tunnel
DARS 1998 – 2014
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Geological-geotechnical investigations for the design of motorway tunnels in Slovenia: the Karavanke, Debeli Hrib, Mali Vrh, Golovec, Trojane, Pletovarje, Golo Rebro, Šentvid and Tabor motorway tunnels
DARS 1990 – 2013
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Consultation, measurements and cooperation in the geological and geotechnical monitoring of all motorway tunnels in Slovenia
DARS 1996 – 2013
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Characterization of rocks in connection with the construction of a railway tunnel through the Karst
DARS 2009 – 2011
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Inspection of the state of motorway tunnels in the Republic of Slovenia
DARS 2010 – 2016