The permanent stabilisation of a collapsed section of the 5.5km dual bore Thirre tunnel in Albania is currently underway after a 50m section collapsed in early November.

The collapse occurred in the centre of the unlined section of the south tunnel where permanent works had not yet been completed. The collapsed section has since been backfilled to half the tunnel depth to provide load and lateral restraint to the sidewalls.

Contractor Bechtel-Enka JV (BEJV) has also constructed shotcrete arches around the circumference of the tunnel to increase stability either side of the collapse.

The south tunnel has been under observation since October when the Albanian Ministry of Public Works chose to close off the unstable section due to unstable ground movements, halting the fit out activities.

The tunnel is part of a new 171km highway that will link the border with Kosovo to the Adriatic Sea. The project, however, has seen numerous setbacks and his running a year behind schedule at nearly double the predicted cost of US$622bn.

This contract is being carried out in three sections with BEJV responsible for the middle 60km stretch containing the tunnel.