On November 15, the Zhuziqing Tunnel, the first long tunnel exceeding 3 kilometers within the Yunnan-Guizhou section of the Chongqing-Kunming High-Speed Railway, was successfully holed through, marking new progress in the construction of the Yunnan-Guizhou section of the railway.

The Zhuziqing Tunnel is located in Yiche Town, Huize County, Qujing City, and was constructed by China Railway No. 9 Engineering Group. The tunnel has a total length of 3,090 meters, with its entrance connecting to the Xiaohebian Bridge and its exit connecting to the Chenjiacun Bridge. The entire tunnel is designed as a single-slope grade of 7.8‰, with a maximum burial depth of approximately 301 meters.

To ensure overall control over tunnel safety, quality, and schedule, the Yunnan-Guizhou No. 3 Bid Project Department of China Railway No. 9 Engineering Group continuously optimized the construction plan, strengthened refined management, strictly controlled risks, improved advance geological forecasting, and increased the frequency of monitoring and measurement. At the same time, the project schedule was worked out in reverse, responsibility implementation was strengthened, and it was ensured that during construction every task had someone watching over it, someone was always on site, and everyone bore their responsibilities, achieving steady and orderly progress in tunnel construction.

"Since the start of tunnel construction, the project department has always taken safety production as the top priority. In response to risk factors such as bedding bias, karst, and harmful gases in the tunnel, the safety management responsibilities of leading cadres at all levels have been clearly defined, and measures such as advance geological forecasting, gas detection for each shift, the 'three inspections per blast,' and 'three-person interlock blasting' have been strictly implemented to ensure the safe holing-through of the tunnel," introduced Li Chunlin, project manager of the Yunnan-Guizhou No. 3 Bid Section of China Railway No. 9 Engineering Group.

The Chongqing-Kunming High-Speed Railway is an important component of the Beijing-Kunming Corridor, one of the main high-speed railway corridors in the national medium- and long-term railway network's 'Eight Vertical and Eight Horizontal' plan. The line has a total length of 699 kilometers, of which the Yunnan section is 388.6 kilometers long, with a designed speed of 350 kilometers per hour. Once completed, the project will become a major corridor for China's southwestern region's opening to the outside world and for the national 'Belt and Road' initiative, better driving economic and social development along the route.