Contracting authority: DARS d. d.
As the lead partner in the joint venture, CVP concluded a contract with Dars d.d. for the execution of construction and renovation works to the supporting arch in the Karavanke tunnel.
The Karavanke tunnel is the longest Slovenian road tunnel. It is 7864 metres long, of which 3450 metres are on the Slovenian part of the tunnel. It was built in 1991 and has been renovated several times at different sections due to active rock mass around tubes.
The renovation was carried out at the distance of 200 metres, two kilometres from the tunnel entrance at the Slovenian side. Since this is a one-tube tunnel and it is not possible to redirect the traffic to other roads, all works were being carried out continuously (24 hours a day, seven days a week), with partial closure of the road and alternating unidirectional traffic. Due to traffic flows and seasonal traffic congestion the works were carried out in two phases: phase 1, from January to June 2014, with an interim suspension of works during holidays, and phase 2, from September to December 2014.
The works included:
- displacement and protection of all electrical-mechanical equipment;
- arrangement of tunnel drainage during construction;
- installation of geotechnical anchors to minimize deformations of the interior lining;
- removal of the carriageway;
- removal and construction of a new deeper supporting arch, by 5-metre segments of sulphate-resistant concrete;
- geological monitoring of excavations, anchor forces and deformations;
- arrangement of tunnel drainage and construction of a new asphalt carriageway;
- renovation of traffic signalization;
- drawing up a project for the execution of works.