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 Huang-Bai Railway), marking a further acceleration of construction on the third-longest tunnel of over 10,000 meters along the entire 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 Huang-Bai Railway. The tunnel poses heavy construction tasks and a long work front, while also facing complex geological challenges such as karst, bedding bias, soft rock deformation, and floor heave. With high construction risks, it is one of the key and difficult control projects along the entire line. The No. 1 inclined shaft of the Dashao Tunnel, which began excavation 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 in the Guizhou section of the Huang-Bai 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 checklist-based" management model, comprehensively strengthening technical briefings and advanced geological forecasting to ensure safe and smooth tunnel entry. It has also 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 tunnel's long length, complex geology, 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, firmly assigning management responsibilities at all levels, and comprehensively strengthening refined process control, the project ensures safe, high-quality, and efficient excavation of the Dashao Tunnel.

It is reported that the Huang-Bai 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. 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.