By Lynda Myer
The single shield hard rock TBM Caucasus, which has been manufactured by CREG, has completed the digging process of the 9 km tunnel, that links the village of Kvesheti with the village of Kobiin, for Lot 1 of the 23km and 2-lane Kvesheti-Kobi highway project.
With maximum progress capacity of 20m per day and of 426m per month,this TBM is 15.08 m in diameter,182 m in length and weights 3900 t, and has completed 8860m of boring with no intermediate access and the topmust overburden of 1121m, whereas the geology is mainly tuff and marl, with a maximum rock strength of 130MPa.
Considering that this hard rock TBM has to overcome the complicated geological conditions and the construction challenges brought by long-distance and deep-overburden tunneling, it has been customized with active articulation system, bi-directional rotation cutter head, dual speed input reducer, which enables the precise adjustment of main machine attitude, the rapid breakout in adverse ground and also the efficient tunneling in good surrounding rock. The TBM has a maximum thrust of 22,600t and a total power of 9900kW.
As the longest in Georgia, this 9 km long tunnel will soon commences its final works and will include excavation, installation of electrical and engineering systems, and road surfacing.
With intention of advancing Georgia as a tourist hub, the Kvesheti-Kobi project takes into account the construction of a new 5 km road leading to Gudauri, while it is due to be provided with all necessary safety standards, and travel time will be decreased. Accordingly, Gudauri resort will be ready to receive more visitors.
The responsibility of funding this project with EUR400.37 million (GEL1.2 billion) value is up to the Asian Development Bank (ADB) and the part of the tunnel construction, with the co-financing of the European Bank for Reconstruction and Development (EBRD).
Including the construction of 5 bridges and 5 tunnels and the rehabilitation of 1 bridge, the Kvesheti-Kobi project is scheduled to be completed in stages between 2024-2025. Although as a passage, this project will link Russia, Georgia, Armenia, Azerbaijan and other countries, due to the snowy winter in the Gudauri area, traffic interruptions often occur. Upon the completion, the traffic on the Gudauri section will continue throughout the winter, which can effectively guarantee the transportation of local production goods and daily necessities.
