On the morning of September 6, the Miaoling Tunnel, a 5,947-meter-long key and difficult control project of the Shenyang-Baihe High-Speed Railway, was successfully holed through, marking that all tunnels on the Shenyang-Baihe High-Speed Railway have been completed. The Shenyang-Baihe High-Speed Railway has a total of 85 tunnels, with a total length of 215.4 kilometers, accounting for 50.1% of the entire line.

The Miaoling Tunnel of the Shenyang-Baihe High-Speed Railway is located in Baishan City, Jilin Province. It is a single-tube double-track tunnel situated at the foot of Changbai Mountain. The geological conditions are dominated by weakly diagenetic volcanic ash and andesite, and the construction conditions are complex. To ensure safe and smooth construction, the contractor China Railway Major Bridge Engineering Group Co., Ltd. followed the construction principles of "short advance per round, strong support, minimal disturbance, weak blasting, frequent observation, and early closure," formulated a complete construction plan, continuously strengthened process management, and adopted corresponding excavation measures for different geological conditions, effectively ensuring safety, quality, and construction efficiency.

To meet the schedule requirements, the Beijing-Harbin High-Speed Railway Company strictly implemented risk control measures, issued monthly excavation risk reminders, and organized the contractor to conduct regular inspections, guarantee-responsibility assignments, and checks; it promptly organized research on the construction plan for the weakly diagenetic volcanic ash stratum of the Miaoling Tunnel and implemented full-process safety monitoring, effectively reducing construction safety risks.

It is reported that the Shenyang-Baihe High-Speed Railway has a total length of 430.1 kilometers. It is an important component of the Shenyang-Jiamusi High-Speed Railway, a rapid passenger transport corridor in eastern Northeast China, and also an important component of the entire Northeast high-speed railway network, with a designed speed of 350 kilometers per hour. After completion and opening to traffic, the shortest travel time from Beijing to Changbai Mountain will be reduced to less than 4 hours, which is of great significance for promoting the effective integration of regional development with the national strategy, deeply empowering the eastern tourism grand loop, further supporting the comprehensive revitalization of Northeast China, and thereby achieving high-quality regional economic development.