The Klokova Tunnel: Ground Support Products by DSI Underground for Greece’s new North-South Connection

Ionia Odos, which is also known as Aftokinitodromos 5, is a new, 196km long north-south motorway connecting northwestern Greece with the Peloponnes Peninsula.

This project also includes the construction of 24 bridges and 4 tunnels. One of the tunnel structures that had to be advanced is the 2,950m long Klokova Tunnel north of Patras. The double tube tunnel is being excavated using the conventional drill and blast method.

To stabilize advancement in the unstable rock layers in which limestone, sand and conglomerates prevail, DSI Underground Austria produced and supplied several ground support systems such as rock anchors for immediate support of the open span area in the prevailing fault zones.

For immediate temporary support, DSI produced and supplied 4.0m to 4.5m long OMEGA-BOLT^® Expandable Friction Bolts. Bonding forces between the friction bolt and the rock mass are caused by form closure and friction transfer between the borehole wall and the rock bolt that is expanded by hydraulic pressure. OMEGA-BOLT^® Anchors reach immediate full load bearing capacity over the entire installed bolt length and were especially well suited for use in the Klokova Tunnel thanks to their low sensitivity against vibrations caused by blasting work.