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A train stops at the entrance of the Qamchiq Tunnel on the Angren–Pap railway line in Uzbekistan on Feb. 27. (Photo/Xinhua)

Qamchiq Tunnel on the Angren–Pap railway line in Uzbekistan.(Photo/Xinhua) 

A ribbon-cutting ceremony was held at the exit of the Qamchiq Tunnel in northeast Uzbekistan on Feb. 27. China Railway Tunnel Group has finished construction of the Qamchiq Tunnel, the longest in Central Asia, on the Angren–Pap railway line in Uzbekistan.

The Qamchiq Tunnel covers a length of 19.2 kilometers. The total length of the excavated part is 47 kilometers. As the longest tunnel in Central Asia, its construction was undoubtedly the most difficult part of whole railway project, which has stumped engineering companies around the world. However, China Railway Tunnel Group cracked the hard nut. The company has signed a $455 million construction contract with the project management side. All new construction will adhere to Chinese standards.

Sun Lijie, Chinese Ambassador to Uzbekistan, said that Qamchiq Tunnel is not only the largest non-research-related cooperative project between China and Uzbekistan, it is also a successful example of Chinese production capacity in the region.

Because of the complicated geological fault, construction teams encountered frequent rock bursts when blasting the mountain. During construction, moderate rock bursts occurred more than 3,000 times. The most serious rock burst caused the collapse of nearly 2,000 cubic meters, which constituted a great safety threat for construction workers.

China Railway Tunnel Group organized a meeting of international rock burst experts and developed scientific methods to tackle the problem. Construction workers also received training about what to do in case of an accident. During the whole construction process, not a single construction worker was injured by the rock burst. Chinese technology thus overcame a very serious obstacle.

Difficult weather conditions were another big obstacle faced by the construction workers. Temperatures reached minus 40 degrees Celsius in the winter. In January 2014, a rare, heavy snow lasted for two weeks, which caused an avalanche in the mountains near the tunnel. Eight meters of snow completely blocked the transportation channel for production and living materials. Using large machinery, the workers labored for three days and nights to re-open the channel. 

With the creative efforts of Chinese workers, tunnel construction was also realized with "Chinese speed." From start to completion, it took just 900 days to excavate a total length of 47 kilometers. The project was ahead of schedule by nearly 100 days, which set a new record for China overseas construction.