On September 15, after 731 days of continuous efforts, the Zhaolin Tunnel of the Xi'an-Yan'an High-Speed Railway was successfully holed through on the 15th. This is the 22nd tunnel to be holed through along the entire Xi'an-Yan'an High-Speed Railway. With the breakthrough of this tunnel, nearly 80% of the tunnel excavation along the entire Xi'an-Yan'an High-Speed Railway has been completed, further accelerating the progress of the project construction.

The picture shows the construction site.

The Zhaolin Tunnel of the Xi'an-Yan'an High-Speed Railway is located in Fu County, Yan'an City, Shaanxi Province, with a total length of 1,768 meters and a maximum burial depth of 170 meters. It is a double-track single-tube tunnel. The tunnel passes through a loess gully and ridge area with great topographic relief. The surrounding rock of the tunnel is of a fragmented structure, coal seams are present within the tunnel, and water seepage in the rock strata is relatively heavy. In addition, both the entrance and exit of the tunnel are located on National Highway G210, making the construction site narrow, with high safety risks and great construction difficulty.

The construction unit, Xicheng Passenger Dedicated Line Shaanxi Company, guided the project department of China Railway No. 8 Engineering Group Co., Ltd. for the Xi'an-Yan'an High-Speed Railway to adjust the surrounding rock classification, support parameters, and excavation methods according to actual site conditions, strengthen tunnel dewatering and drainage work, and ensure the smooth excavation of the tunnel face. For special surrounding rock and coal seam sections, a small-footage non-blasting excavation technique was adopted to ensure the smooth progress of tunnel construction.

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

According to reports, 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. This is of great significance for further advancing the Western Development Strategy, supporting rural revitalization in the old revolutionary base areas, accelerating the construction of the Baotou-Haikou high-speed railway corridor, further improving and optimizing the layout of the national high-speed railway network, and enhancing Shaanxi Province's locational advantages and its hub status in the national railway network.