The Chongqing-Kunming High-Speed Railway, abbreviated as the Chongqing-Kunming High-Speed Rail, is a rapid railway connecting Chongqing and Kunming, passing through Sichuan, Guizhou, and Yunnan. It spans approximately 698.96 kilometers, with 21 stations along its route, and has a design speed of 350 kilometers per hour.
The Zhaotong Tunnel is part of the Chongqing-Kunming High-Speed Railway, stretching approximately 16.2 kilometers, including a 4.2-kilometer section through coal seams. The third horizontal shaft of this tunnel is located in Suoye Village, Luozhe River Town, Yilang County, Zhaotong City, Yunnan Province, at an altitude of about 1700 meters. The climate here is cold and humid, with more rainy days than sunny ones throughout the year, making construction conditions extremely challenging. The geological formation primarily consists of limestone, with abundant underground karst water resources.
The LanHi LGM312U intelligent integrated arch anchor trolley features an engineering chassis and is equipped with a single anchor system. The machine features four-wheel steering, four-wheel drive, two-way driving and other functions. Its diesel-electric dual power system supports electric construction and diesel-powered emergency operations. The three-arm remote control can meet the requirements for prefabricated arch frame installation, operation of various benching methods and precise positioning adjustment of the arch frame. The arch frame can handle under-excavation and welding operations during installation, and the tunnel itself is very flexible.
Construction of the Chongqing-Kunming High-Speed Railway in the Chongqing and Sichuan sections began on September 29, 2019. By February 20, 2022, the first horizontal shaft of the Zhaotong Tunnel achieved smooth breakthrough. As of February 2024, excavation of the Zhaotong Tunnel has exceeded 7 kilometers, with the third horizontal shaft expected to enter formal excavation by the end of April. The Chongqing-Kunming High-Speed Railway's Chongqing-Sichuan section is scheduled to be completed and opened to traffic by the end of 2024.