On August 10, the Yijun Tunnel of the Xi'an-Yan'an High-Speed Railway was successfully holed through. The breakthrough of this longest tunnel on the Xi'an-Yan'an High-Speed Railway marks that more than 90% of the total tunnel excavation for the entire line has been completed.

The successfully holed-through Yijun Tunnel of the Xi'an-Yan'an High-Speed Railway

The Yijun Tunnel of the Xi'an-Yan'an High-Speed Railway is located in Yijun County, Tongchuan City, Shaanxi Province, with a total length of 17,509 meters. The tunnel is situated in the Loess Plateau region, with a maximum burial depth of 395 meters. It passes beneath unfavorable geological conditions such as gullies, fault fracture zones, expansive strata, and coal-bearing strata, posing high construction safety risks.

It is understood that the Xi'an-Yan'an High-Speed Railway has a total of 47 tunnels and 66 bridges, with a bridge-to-tunnel ratio of 92%. The Yijun Tunnel is a Class I high-risk tunnel, and its breakthrough marks that the tunnel works of the Xi'an-Yan'an High-Speed Railway are nearing completion, creating favorable conditions for subsequent ballastless track construction. During tunnel construction, the contractor deeply advanced intelligent construction and intensified the application of technological innovation, solving a series of on-site operational challenges. Multiple new types of equipment were successively deployed, and an intelligent tunnel management system was established, enabling the use rate of mechanized and intelligent supporting equipment in the Yijun Tunnel construction to reach 94%, effectively improving construction efficiency. As of now, 41 of the 47 tunnels on the entire Xi'an-Yan'an High-Speed Railway have been holed through, and cumulative excavation of the main tunnel bore has reached 95% of the designed total.

The site of the breakthrough ceremony for the Yijun Tunnel of the Xi'an-Yan'an High-Speed Railway

The Xi'an-Yan'an High-Speed Railway is the first high-speed railway in the old revolutionary base area of northern Shaanxi and an important component of the Baotou (Yinchuan)-Haikou high-speed railway corridor in the national high-speed railway network. Together with the Xi'an-Chongqing High-Speed Railway currently under construction, it forms a major north-south corridor and is an important constituent of the main framework of Shaanxi Province's "米"-shaped high-speed railway network. After the line is completed and put into operation, the travel time from Xi'an to Yan'an will be shortened from the current 2.5 hours to about 1 hour.