On September 13, the reporter learned from the Southwest Institute of China Railway Science Research Institute that on September 10 local time, the China-made world's largest-diameter full-face hard rock tunnel boring machine (TBM) "Caucasus" officially began boring in the Kvesheti-Kobi (KK) tunnel in Georgia. The KK tunnel is the longest highway tunnel in Georgia, and the Geology Institute of the Southwest Institute of China Railway Science Research Institute is responsible for geological consulting and advanced geological forecasting for the tunnel.

The first section of the Kvesheti-Kobi stretch of Georgia's North-South Highway is located in the Mtskheta-Mtianeti region and includes a 9 km single-tube, double-track main tunnel, a 9 km small-section emergency tunnel and 1 km of roadbed works. The KK tunnel is currently the longest highway tunnel in Georgia.

During construction inside the KK tunnel, the world's largest-diameter full-face hard rock tunnel boring machine (TBM) "Caucasus" is being used. The TBM has a diameter of 15.08 meters, a total length of 182 meters and a total weight of 3,900 tonnes. It was designed and built entirely to Chinese standards and independently manufactured by the Chinese side.

The Geology Institute of the Southwest Institute of China Railway Science Research Institute is responsible for geological consulting and advanced geological forecasting for the tunnel, using methods such as geological surveys and geophysical prospecting to identify hidden adverse geological conditions ahead of the tunnel in advance, safeguarding the smooth boring of the "Caucasus" TBM.

Once the KK tunnel is completed, travel time on this section of the highway will be shortened from 1 hour to 20 minutes, greatly improving the traffic efficiency and driving safety of Georgia's North-South Highway. It will strongly enhance Georgia's status as an important node on the Silk Road corridor and help turn Georgia into an important transport and logistics hub connecting Central Asia and the Far East with Turkey and Europe.