On July 3, after 19 consecutive months of arduous efforts by railway builders, the Huashan Tunnel on the newly built Chongzuo-Pingxiang Railway (hereinafter referred to as the Chongping Railway) was successfully holed through. This is the first Grade I high-risk karst tunnel to be holed through on the Chongping Railway. As of now, 17 of the 22 tunnels along the entire Chongping Railway line have been successfully holed through.

The Huashan Tunnel is located in Shangjin Township, Longzhou County, Chongzuo City, Guangxi. With a total length of 4,206 meters and a maximum burial depth of approximately 225 meters, it is a key and difficult project along the entire line. The tunnel features strongly developed karst and complex geological structures. During construction, 7 super-large karst caves and more than 150 medium and small karst caves were discovered, presenting characteristics such as numerous unforeseeable factors including mud and water inrushes and collapses, high safety risks, and great construction difficulty. "On average, 37 karst caves were found per kilometer, with the largest one measuring more than 250 meters in both length and width and over 80 meters in height," said Yang Yanwei, project manager of the Chongping Railway Section 2 project of China Railway No. 4 Engineering Group, which is responsible for the tunnel's construction.

It is understood that the Huashan Tunnel is near the famous Huashan Scenic Area in Guangxi. In accordance with relevant environmental protection requirements, the participating construction units adopted measures such as filtration and sedimentation treatment for construction wastewater and domestic sewage, allowing discharge only after meeting standards. For dangerous rocks and falling stones on slopes, manual clearing and active and passive protective netting were used to intercept them, ensuring that the impact on the original topography and landforms is minimized.

The main line of the Chongping Railway has a total length of 81.52 kilometers, with a bridge-to-tunnel ratio of 85.63%. The line starts in Jiangzhou District, Chongzuo City in the east, passes westward through Ningming County and Longzhou County, and ends in Pingxiang City, with conditions reserved for future extension to Vietnam. It has four stations: Chongzuo South, Ningming East, Longzhou, and Pingxiang East. The entire line began full-scale construction in July 2022 and is expected to be completed and opened to traffic in 2025. By then, it will form an important international transport corridor between China and ASEAN, and is of great significance for improving the regional road network layout, promoting border prosperity and enriching the people, building an important economic corridor between China and ASEAN countries, and making Guangxi an important node of the "Belt and Road."