On September 13, excavation officially began at the No. 1 inclined shaft of the Dashao Tunnel on the Huangtong–Baise Railway (hereinafter referred to as the Huangbai Railway), marking a further acceleration of construction on the third-longest over-10,000-meter tunnel in the Guizhou section.

According to reports, the Dashao Tunnel is located in Wangmo County, Qianxinan Prefecture, Guizhou Province, with a total length of approximately 10,875 meters. It is one of three tunnels exceeding 10,000 meters in length in the Guizhou section of the Huangbai Railway. The tunnel poses heavy construction tasks and a long work front, and must also contend with complex geological challenges such as karst, bedding bias, soft rock deformation, and floor heave, entailing high construction risks. It is one of the key and difficult control works of the entire line. The No. 1 inclined shaft of the Dashao Tunnel, whose excavation began this time, has a total length of 827 meters and is responsible for 4,095 meters of main tunnel construction.

According to reports, Section 5 of the pre-station works of the Guizhou section of the Huangbai Railway is approximately 31.3 kilometers long and includes two tunnels exceeding 10,000 meters. Since the project started, the construction team has followed a "grid-based, quantified, and list-based" management model, comprehensively strengthening technical briefings and advanced geological forecasting to ensure safe and smooth tunnel entry, and has deployed information systems such as advanced horizontal drilling, ground-penetrating radar, construction personnel positioning, tunnel loudspeaker communication, and emergency telephones to ensure the construction safety of tunnel workers. In view of the characteristics of the tunnel, such as its long length, complex geology traversed, and relatively high safety risks, the Dashao Tunnel has a total of five construction points—the entrance, No. 1 inclined shaft, No. 2 inclined shaft, cross adit, and exit—forming six working faces. By scientifically preparing special tunnel construction plans, tightening management responsibilities at all levels, and comprehensively strengthening refined process control, the safe, high-quality, and efficient excavation of the Dashao Tunnel is ensured.

It is reported that the Huangbai Railway connects to the Shanghai–Kunming Railway in the north and the Nanning–Kunming Railway in the south. It is an important component of the western corridor of the New Western Land-Sea Corridor, with a main line length of approximately 315 kilometers and a design speed of 160 kilometers per hour. It is a national Class I electrified railway with a construction period of five years, of which the Guizhou section has a main line length of approximately 173 kilometers and a bridge-tunnel ratio of 81.6%. Once completed, the project will further improve the regional road network layout and become a convenient corridor from northern Guizhou to the sea, which is of great significance for accelerating the construction of the New Western Land-Sea Corridor and promoting coordinated regional economic and social development.