On the morning of November 21, the Luochuan Tunnel of the Xi'an-Yan'an High-Speed Railway was successfully holed through. This is the longest pure loess tunnel on the entire line, laying a solid foundation for the subsequent construction of the Xi'an-Yan'an High-Speed Railway and at the same time accumulating valuable experience for the construction of similar complex-geology tunnels in China.

The Luochuan Tunnel of the Xi'an-Yan'an High-Speed Railway is located within Luochuan County, Yan'an City, Shaanxi Province, with a total length of 4,140.43 meters. It is a single-tube double-track tunnel and is also the longest pure loess tunnel on the entire Xi'an-Yan'an High-Speed Railway line. The tunnel is situated in the loess plateau with a maoliang (loess ridge) landform structure, where the geological structure and natural conditions are extremely complex. The tunnel site area is mainly composed of collapsible loess strata, with soft-plastic layers present in many locations and a minimum burial depth of only 8 meters. The surface environment is complex, and the tunnel passes beneath national highways, buildings and other structures multiple times. During construction, risks such as deformation, falling blocks and roof collapse are prone to occur, making construction difficult and safety risks extremely high. It has been classified as a Class I high-risk loess tunnel and is a key and difficult control project on the entire line.

The Xi'an-Yan'an High-Speed Railway is the first high-speed railway in the old revolutionary base area of northern Shaanxi. It is an important component of the Baotou (Yinchuan)-Haikou high-speed railway corridor in the national high-speed railway network, and together with the Xi'an-Chongqing High-Speed Railway and the Yan'an-Yulin High-Speed Railway currently under construction, it forms a major north-south corridor. It is an important constituent of the main framework of Shaanxi Province's "rice-shaped" high-speed railway network and is a key construction project during the 14th Five-Year Plan period. The line has a total length of 299.8 kilometers, with a construction standard of a double-track high-speed railway and a design speed of 350 kilometers per hour. 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.