On April 20, after more than three years of intensive work, both tubes of the Huashan No. 1 Tunnel on the Yanjiang Expressway were successfully holed through. With this, all mainline tunnels in Sections ZCB1-2/3 of the Ningpan segment have been fully holed through, launching the final push toward the June 30 opening target for the 68 km Ningnan-to-Panzhihua segment of the Yanjiang Expressway.

It is understood that the Huashan No. 1 Tunnel is located in Zhushou Town, Ningnan County, Liangshan, with a total length of 2,431 m. It is being excavated from both ends, and the surrounding rock is predominantly Class IV and V. The tunnel portals sit in a narrow ravine (Jiapigou) with high gully flow, steep and dangerous terrain, and great construction difficulty; bringing in materials and equipment is difficult, and it is hard to open up working faces. Tunnel construction also faces challenging conditions including minor gas, fractured rock masses, poor surrounding-rock stability, large water inflow, and complex geological structures.

During tunnel construction, local governments provided strong support. By actively coordinating resources from all parties, they provided robust guarantees for the project.

It is reported that the Yibin-to-Panzhihua Expressway, or Yipan Expressway, also known as the Sichuan Yanjiang Expressway, has a total length of more than 448 km. It is an important component of the Chengdu-to-Lijiang Expressway. The Yipan Expressway runs upstream along the Jinsha River from Yibin City, passing through Xinshi Town in Yibin and entering Leibo, Jinyang, Ningnan, Huidong, and Huili in Liangshan, before finally reaching the urban area of Panzhihua. The project is designed as a dual-carriageway, four-lane expressway with a design speed of 80 km per hour. Construction of the entire line began in 2017, and the project is scheduled to be completed and opened to traffic in 2025.