On July 6, the Xiaomiaozhai Tunnel, a double-arch tunnel on the Chongqing-Kunming High-Speed Railway constructed by China Railway No. 5 Engineering Group, achieved smooth breakthrough on both its left and right tubes, marking a major breakthrough in the construction of the Chongqing-Kunming High-Speed Railway.

The Xiaomiaozhai Tunnel is located in Yiliang County, Zhaotong City, with a total length of 198 meters. It is a shallow-buried tunnel with a maximum burial depth of only 25 meters, and it also passes beneath Provincial Highway S352 and a village, posing extremely high safety risks. Through research projects on "Research on Shallow-Buried Multi-Arch Construction Technology for Railway Tunnels" and "Application of Double-Arch Structures in High-Speed Railway Tunnels," the construction team organized the work meticulously and carried out scientific construction, overcoming difficulties in tunnel construction such as shallow burial, underpassing, and double-arch structures, achieving a safe and smooth breakthrough of the tunnel and laying a solid foundation for the full opening of the Chongqing-Kunming High-Speed Railway.

As an important transportation artery project in China, the Chongqing-Kunming High-Speed Railway is of far-reaching significance for strengthening regional connectivity and promoting economic development. Once completed and opened to traffic, the project will connect Yunnan, Guizhou, Sichuan, Chongqing and other provinces and municipalities, becoming an important corridor for Southwest China's opening-up and for the Belt and Road route to ASEAN. It will greatly promote high-quality regional economic development and inject strong momentum into the region's economic takeoff.