(Photo/Xinhua)
On the morning of May 9, China's first subway tunnel crossing the Yellow River proceeded smoothly. The tunnel is part of Subway Line 1 in Lanzhou, the capital city of northern China's Gansu province. This success paves the way for the completion of the whole tunnel by the end of this year, Xinhua News Agency reported.
The whole subway tunnel is 2,119 meters long, and the section that crosses the Yellow River is 317 meters long. The tunnel's depth ranges from a maximum of 36.5 meters to just 19.5.
The project was previously pronounced a "world-class problem" by Qian Qihu, a tunnel expert and fellow researcher at the Chinese Academy of Engineering.
