On July 8, amid light drizzle, construction machinery rumbled continuously at the Machang Double-Track Grand Bridge site on the Guizhou section of the Guiyang-Nanning High-Speed Railway in Dushan County, Qiannan.

With the erection of the final box girder, the bridge was successfully closed. This marks the on-schedule completion of the small-mileage box girder erection task for Section 5 of the Guizhou section of the Guiyang-Nanning High-Speed Railway, laying the foundation for ensuring that the ballastless track test section of the Guizhou section of the Guiyang-Nanning High-Speed Railway is the first to begin construction this month.

It is reported that the Machang Double-Track Grand Bridge on the Guiyang-Nanning High-Speed Railway, constructed by China Railway No. 4 Engineering Group Co., Ltd., has a total length of 1026.219 m and a maximum pier height of 77 m, all using single-box single-cell prestressed concrete simply supported box girders. The bridge site area features undulating mountains and large slope variations, with unfavorable geological conditions such as bedding planes, solution troughs, solution trenches, and surface landslides.

From the pouring of the first bored pile on November 16, 2018, to the capping of the last hollow pier on January 16, 2021, the substructure construction was completed over 792 days, overcoming difficulties such as steep mountainous terrain and high-altitude operations.

The Guiyang-Nanning High-Speed Railway, with a design speed of 350 km/h, is an important component of the Baotou-Haikou corridor, one of China's "Eight Vertical and Eight Horizontal" high-speed railway main corridors, and is also the first high-speed railway in Southwest China designed for a speed of 350 km/h.

Once completed, the Guiyang-Nanning High-Speed Railway will join the Chengdu-Guiyang, Guiyang-Guangzhou, and Chongqing-Guizhou high-speed railways to form a rapid railway corridor for passenger exchange between the Sichuan-Chongqing-Guizhou and Northwest regions and the coastal areas of South China, creating a convenient main corridor for passenger exchange between the Sichuan-Chongqing-Guizhou and Northwest regions and Nanning, the Beibu Gulf, western Guangdong, Hainan, and ASEAN countries.