On August 1, the Luorongzhuang Tunnel of the Chongqing-Kunming High-Speed Railway was safely holed through, laying the foundation for the opening and operation of the entire line.

According to reports, the Luorongzhuang Tunnel is located in Songming County, Kunming City, Yunnan Province, with a total length of 5,260 meters. It is a single-tube double-track tunnel with complex geological conditions, and it also passes beneath the existing Shanghai-Kunming High-Speed Railway and the Yinkun Expressway. The construction is highly difficult and the safety risk is high, making it a key controlling project in the Kunming hub section of the Chongqing-Kunming High-Speed Railway.

To ensure the safe and orderly progress of tunnel construction, the participating units studied and optimized the construction organization plan, fully applied engineering measures such as controlled blasting, mechanical excavation, and high-precision advanced large pipe roof to improve construction efficiency. At the same time, an inclined shaft was added 500 meters from the tunnel exit, increasing the original four working faces to five and achieving early holing-through of the tunnel.

It is understood that the Chongqing-Kunming High-Speed Railway is a key component of the Beijing-Kunming corridor of the national "Eight Vertical and Eight Horizontal" high-speed railway network, with a total length of 699 kilometers, of which the Yunnan section is 388.6 kilometers long. At present, 23 of the 63 tunnels in the Yunnan section of the Chongqing-Kunming High-Speed Railway have been holed through, and the construction of 10 key controlling bridge and tunnel projects is progressing smoothly. As the first high-speed railway in Yunnan Province designed for a speed of 350 kilometers per hour, once the entire Chongqing-Kunming High-Speed Railway is completed and opened to traffic, the travel time from Chongqing to Kunming is expected to be shortened from the current 5 hours to as fast as 2 hours.