On the morning of August 31, 2023, machines roared inside the tunnel and everyone was exhilarated. With the completion of the final excavation at the tunnel face, after more than 300 days and nights of arduous construction, the Dongjiaqing Right Line Tunnel undertaken by China Railway 11th Bureau Group was successfully holed through, becoming the "first breakthrough" among the tunnels in Section 1 of the Panxing Railway, achieving a breakthrough at a major key milestone and marking that the construction of Section 1 of the Panxing Railway has reached a new level.

The Dongjiaqing Right Line Tunnel has a total length of 831.0524 m and is a single-track tunnel with a design speed of 160 km/h. The maximum buried depth of the tunnel is about 55 m. The tunnel area belongs to the karst-erosion structural low-medium mountains of the Yunnan-Guizhou Plateau, and a karst erosion flat top has formed above the tunnel. The absolute elevation of the tunnel area is 1860-1980, with a maximum relative height difference of 120 m.

Since entering the tunnel for construction on August 8, 2022, the project department has strictly controlled the construction links and rigorously managed the working procedures. Under adverse geological conditions such as frequently encountered karst cavities, water seepage, and gently inclined rock strata, they have fully carried forward the spirit of the "Railway Corps" of daring to fight tough battles and fearing no hardship. In strict accordance with the principles of short advance, strong support, early closure, and weak blasting, they have effectively supervised safety, quality, environmental protection, and progress, steadily advancing the project construction. Through days and nights of tenacious struggle, they achieved the expected goal of "zero accidents," securing a phased victory for the project construction.

In order to accelerate the construction schedule and promote high-quality development led by Party building, the project department has always given top priority to safety and quality, strictly implementing standardized operations and refined management during the process, strictly grasping terminal control, and focusing on quality projects. At the same time, the "two-hour safety confirmation" system has been implemented to hold the safety bottom line, eliminate safety hazards in the bud, and ensure that the overall construction of the project is stable and controllable.

The successful holing-through of the Dongjiaqing Right Line Tunnel this time has greatly boosted the morale of all project staff and laid a solid foundation for the subsequent construction of the project on schedule. In the follow-up construction, all personnel will, as always, adhere to the iron army spirit of taking the overall situation into account, being willing to tackle tough challenges, and being dedicated to making sacrifices, fully demonstrating the corporate image, and completing all construction tasks of the Panxing Railway with guaranteed quality and quantity.