Mammoth Chinese hard-rock TBM launches in Georgia

13 September 2021


Crews from China Railway Tunnel Group (CRTG) have completed in three months the assembly and launch of one of the world's largest diameter, full-face, hard rock tunnel boring machines for the Kvesheti-Kobi highway tunnel project in Georgia.

The 15.08m-diameter machine will bore the 8,860m-long section of the project, which is located at an altitude of around 2,000m and passes through the Gudauri Mountain – part of the Greater Caucasus Mountain Range in Georgia.

The alignment is expected to pass through a geology comprising mainly tuff and marl with a maximum overburden of 1,121m and an average of more than 600m.

The 182m-long TBM weighs 3,900t, has a maximum thrust of 22,600t and a total power of 9,900kW. It was jointly developed by CRTG and China Railway Engineering Group (CREG).

Forming part of the Belt and Road Initiative, the KK Highway will reduce Georgia’s reliance on shipping and become a key route linking Russia, Georgia, Armenia, Azerbaijan and other surrounding countries. The central section passes through the Gudauri Mountain area which experiences frequent winter snowfalls that can disrupt traffic flows for continuous periods of more than 20 days.