On February 22, after more than 230 days of intensive construction by all the construction personnel, the connecting line of the Beijing-Harbin high-speed railway to the hinterland of Liaoning-the Chaoling high-speed railway Heishigou tunnel was successfully completed. This is the first tunnel through the entire Chaoling high-speed railway.

The construction of the Chaoling High-speed Railway started on October 11, 2017. The line is drawn from Chaoyang Station of the Beijing-Harbin High-speed Railway, passing through the three cities of Chaoyang, Beipiao and Jinzhou in Liaoning, and connected to Linghai South Station of the Qin-Shen Passenger Train. The total length of the line is 105.6 kilometers and the design speed is 350 kilometers per hour. The line crosses the hilly area of northwest Liaoning, with bridges and tunnels accounting for 71% of the whole project.

Heishigou Tunnel is located in Batuying Township, Chaoyang City, Liaoning Province. It is a single-hole double-line tunnel with a total length of 271 meters. The tunnel is located in a low hilly area, with a shallow body and a maximum depth of only 24.5 meters. The dangerous rocks on the top of the mountain are steep, the weathered cracks are serious, the hillside is full of stones, the geological conditions are complex, and there is a 600000-volt high-voltage iron tower on the top of the cave, which is difficult to construct.

The project team of China Railway Shanghai Engineering Bureau Group actively organized expert review meetings to carefully review the construction scheme for entering and leaving the tunnel and the special safety scheme, and continuously optimized the construction scheme according to the advanced geological forecast and monitoring measurement data in the later construction. The construction personnel mainly take the step excavation method, and adopt the advanced support weak blasting excavation method during the construction of entering and leaving the tunnel, which solves the problem of slow construction progress of the middle pipe shed and ensures that the 600000 volt iron tower on the top of the tunnel realizes zero settlement of the foundation. Adhere to the attitude of "high standards, strict requirements and zero tolerance" to ensure that each process meets the design requirements; Implement the leadership guarantee system and night inspection system, the team members of the key process work area and the technical backbone of the engineering department are required to take the shift to ensure the safety and quality of the tunnel and the progress of the construction period.

As an important part of the high-speed railway network in Northeast China, the Chaoling high-speed railway connects the Beijing-Kazakhstan high-speed railway, which will further extend the rapid passenger transport channel in and out of the Northeast, and form an effective connection between the open city of Dalian in Northeast China and the underdeveloped areas in Western Liaoning. It is of great significance to promote economic and social development and revitalize the old industrial base in Northeast China.

The Chaoling high-speed railway is expected to be completed and opened to traffic in 2021, when the time for southern Liaoning to enter Beijing will be shortened from the current 6 hours to about 4.5 hours.