As a natural barrier of the Hexi Corridor, Wushaoling has been the east gate of the Central Plains and the Guanzhong Plain into the Hexi Corridor since ancient times. It is also a must pass through the ancient Silk Road. It is also known as the Silk Road along with the Gulang Canyon under the mountain. Portal.

It is cold and hypoxic, and the air is thin. The main peak is 3562 meters above sea level. The annual average temperature is -2.2°C. The temperature difference between day and night is large. The climate is volatile and the natural environment is harsh. There is a description of Wushaoling in the historical records that "flies snow in midsummer, and cold bones". Moreover, Wushaoling has complicated geological conditions and many fault zones, so it is known as the "Geological Museum". The Lanzhou-Zhangye Line 3 and 4 Railway (hereinafter referred to as the "Lanzhou-Zhang Line 3 and 4 Railway"), which is under construction, has to traverse this lofty mountain range. Among them, the Xinwushaoling tunnel, which was constructed by China Railway Third Bureau of China Railway Group, is the key to this grand feat.

The first generation of Wushaoling Tunnel

In the era of carrying hands and shoulders, although the 30,000 road-building army was brave, but restricted by backward technology, they had to take the form of an extension line, letting the Lanxin Railway go around the mountain stream and cross Wushaoling. Among the seven cross-ridge tunnels, the longest Wushaoling Tunnel was only 967.8 meters long. Construction started in 1953 and completed in May of the following year. Although it cannot compare with today’s tunnels of thousands of meters, it was already the same at that time. An amazing feat.

The second generation Wushaoling Tunnel

Construction of the second generation Wushaoling Tunnel (namely, the Wushaoling Tunnel on the Lanzhou-Wuwei Second Line of the Lanzhou-Xinjiang Railway) started in 2003. The full name is "Wushaoling Extra-long Tunnel". It is a single-hole single-line design with a total length of 20.05 kilometers. It is the longest tunnel in Asia. Although a large number of mechanized operations have been adopted, many mechanical equipment still relies on imports and have not been fully domestically produced. The level of intelligence and automation is not high enough compared with the current level.

The Wushaoling super-long tunnel was operated with more than a dozen working faces at the same time, and it took more than three years to realize the double-track opening of the tunnel in August 2006. It only takes 15 minutes for the train to cross Wushaoling at a speed of 140 kilometers.

The third generation Wushaoling Tunnel

The third-generation Wushaoling Tunnel, whose full name is "Xin Wushaoling Tunnel", which started construction in 2019, is located on the east side of the existing Wushaoling extra-long tunnel and is parallel. It is a control project for the Lanzhang Third and Fourth Line Railway. , The design speed is 250 kilometers per hour, the total length is 17.125 kilometers, the maximum buried depth is 952 meters, and the planned construction period is 4 years.

The rock quality in this section is weak, the rock mass is broken, and there are many geological risks. China Railway Third Bureau has always implemented the concept of environmental protection in the construction process, highlighting the scientific and technological content everywhere. The construction adopts high-precision localized machinery and equipment such as cantilever roadheaders, wet spray manipulators, self-propelled hydraulic inverted arch bridges, lining trolleys, etc., to achieve the goals of mechanization, automatic substitution, and intelligent unmanned; the management process introduces BIM construction Advanced technologies such as simulation, VR experience, and intelligent monitoring ensure that safety and quality are controllable. Among them, the self-developed laser section scanning program can effectively monitor the shrinkage and deformation of the entire tunnel during the excavation process. Once an abnormality is found, the construction staff will be reminded in time to take measures to strengthen it.

As the tunnel is located in an ecological protection zone, the builders of the Third China Railway Administration have adopted various measures to protect the ecological environment. "For construction wastewater, we built a new sewage treatment station to purify it. In addition, we used the existing inclined wells to reduce excavation, and at the same time plant trees and greens at the entrances to reduce soil erosion. All the ballasts that came out of the tunnels, we all Transported to the abandoned ballast yard outside the protected area for storage.” The person in charge of the project said. Editor/Tian Zengpeng