Konovo Tunnel – 3rd Development Axis

Improved Regional Connections in Koroška

The Konovo Tunnel is part of Slovenia’s Carinthia Road connection and the wider 3rd Development Axis infrastructure project. The construction contains a 17,5 kilometres four-lane road between the Velenje South and Slovenj Gradec South interchanges, as well as a 1,9-kilometre two-lane joining road N1 between Konovo and the Škale junction. Located on the N1 connection, the Konovo tunnel is a single-tube structure with an intended speed of 70 km/h. It contains two 3,25-metre traffic lanes, a 0,50-metre intermediate lane and 0,35-metre side lanes on both sides.

The tunnel is 497,33 metres long and is intended for two-way traffic. In the tunnel there are 18 audit niches, one electrical niche, two emergency call boxes and one emergency call niche. A power facility at the northern portal supplies the tunnel lightning system during operation.

Based on geological investigations, mechanical excavation is carried out in accordance with the New Austrian Tunnelling Method (NATM). This also applies in tunnel sections, areas with weak coverage and tectonic zones. Construction primarily progresses from the northern portal to reduce the cost of mobilizing the construction site. The tunnel breakthrough is planned near the southern portal, so only a short stretch on the southern side will need to be excavated.

Scope of Work

• Mechanised Tunnelling 
• Tunnel construction and excavation work 
• Stabilization of the tunnel 
• Safety system installation
• Portal construction works