On the morning of September 10, the right tube of the Huoshan Tunnel, one of the "two bridges and two tunnels" control works of the Ningnan-Panzhihua section (Ningnan to Panzhihua) of the Yanjiang Expressway, was holed through, marking another major step forward toward the goal of opening the Huili-Panzhihua section to traffic by the end of this year.

The right tube of the Huoshan Tunnel was successfully holed through

The entrance of the Huoshan Tunnel is located in Baiji Village, Xiaoheiqing Town, Huili City, Liangshan Prefecture, and the exit is in Tazha Village, Xinjiu Town, Yanbian County, Panzhihua City. The left tube has a total length of 7,145 meters and the right tube 7,197 meters, with a maximum burial depth of about 466.9 meters. It is a double-tube, two-way extra-long gas tunnel.

Since entering the site in June 2020, after 1,562 days and nights of meticulous construction, the builders have overcome difficulties and risks such as fault fracture zones, water and mud inrush, gas, and rockbursts. Guided by 18 research topics including intelligent advance identification of surrounding rock and advance support systems, and combining solid tunnel construction with cutting-edge industry technologies, they effectively resolved construction difficulties such as large deformation of carbonaceous shale and achieved innovative breakthroughs including full-face excavation in Class V surrounding rock and fully mechanized construction of the upper and lower benches in carbonaceous shale, while accumulating valuable experience for the treatment and pricing of large deformation in soft rock.

The successful holing-through of the right tube of the Huoshan Tunnel marks breakthrough progress in the east-west external connection corridor of the one prefecture and one city in the Panxi region, and lays a solid foundation for achieving the goal of opening the Huili-Panzhihua section of the Yanjiang Expressway to traffic by the end of this year. It is of great significance to the development of Panzhihua and the counties and cities along the Liangshan route, as well as to the building of Sichuan's southward opening gateway.