On August 8, the parallel heading of the Yuezhi Mountain Tunnel on the Emeishan-Miyi section of the Chengdu-Kunming Railway capacity expansion project, constructed with the participation of China Railway 18th Bureau Group, was successfully holed through, laying a solid foundation for the full breakthrough of the Yuezhi Mountain Tunnel.

Located in Jinkouhe District of Leshan City and Ganluo County of Liangshan Prefecture in Sichuan Province, the Yuezhi Mountain Tunnel is 14,085 meters long and is a single-tube double-track tunnel with a maximum burial depth of 1,810 meters. It is a major difficult, controlling and high-risk project on the entire line. The tunnel lies in the fractured zone of the Dadu River, Niri River and high mountain gorges, where natural disasters such as collapses, landslides, mudslides and floods are prone to occur. Construction faces difficulties including numerous geological hazards, high engineering risks, a short effective construction period and great difficulty in ensuring transportation.

To strengthen the ventilation, drainage and rescue functions of the Yuezhi Mountain Tunnel and increase the number of working faces so as to speed up construction, the project added a parallel heading and an inclined shaft. The parallel heading of the Yuezhi Mountain Tunnel holed through this time is the main auxiliary tunnel for the construction of the main tunnel of the Yuezhi Mountain Tunnel on the Chengdu-Kunming Railway. It is 12,570 meters long (including 1,731 meters of inclined shaft), and a total of 25 cross passages are set between the parallel heading and the main tunnel to assist the main tunnel construction.

To ensure the milestone targets are achieved on schedule, the project team further strengthened technical research and strictly managed construction; focused on problem orientation and optimized construction organization; and, closely relying on the group company's "Nine Comparisons and Six Creations" labor competition, strictly kept to the schedule while ensuring safety and quality, and successively carried out a series of labor competitions and construction campaigns. During this period, the project team overcame a series of construction difficulties one after another, kept pushing toward the upper targets, and set a monthly excavation and support construction record of 276 meters.

Since entering the tunnel for construction in August 2016, all participating employees have braved difficulties and fought tenaciously, overcoming many severe difficulties including the impact of several extraordinary rainstorm and mudslide disasters, and ensured safe production of the project. Since mobilization, in the face of difficulties and challenges, the project team has persisted in carrying forward the new and old "Chengdu-Kunming spirit," united as one, and devoted itself wholeheartedly to project construction, contributing the strength of the 18th Bureau to ensuring the Emeishan-Miyi section of the Chengdu-Kunming Railway is completed and opened to traffic on schedule!