On September 19, the right tube from the exit to the cross passage of the Jinyang Tunnel, the longest tunnel on the entire Xichang-Zhaotong Expressway, was holed through.

The Jinyang Tunnel on the Xichang-Zhaotong Expressway is located in Jinyang County, Liangshan Prefecture, Sichuan Province. With a total length of 12.17 kilometers and a maximum burial depth of 1,723 meters, it is a key control project and the longest tunnel on the entire Xichang-Zhaotong Expressway.

The tunnel is located in a remote area and passes through multiple fault zones, 27 strata and 43 lithological contact zones. Construction is carried out in phyllite and high-ground-stress sections, facing various adverse geological conditions such as water and mud inrush, concealed karst, large deformation of soft rock and rockburst in hard rock. In addition, many difficulties, such as ventilation challenges in the extra-long tunnel, large water inflow in the inclined shaft and main tunnel, interference from cross construction, difficulty in material supply and protection of water sources, have posed great challenges to the builders.

In response to the key and difficult points of the project, the builders took measures such as optimizing the construction plan, strengthening work shift management, enhancing equipment support and improving processes and methods, effectively ensuring the safe, efficient and smooth holing-through from the exit right tube to the cross passage.

The section from the exit double tubes to the cross passage of the Jinyang Tunnel has a total length of 7.1 kilometers, of which 6.9 kilometers have been excavated. It is expected that the successful holing-through from the exit double tubes to the cross passage will be achieved by the end of the year. The auxiliary main tunnel from the exit and cross passage of the Jinyang Tunnel has a total length of 11.9 kilometers, of which 8.3 kilometers have been excavated. The Jinyang Tunnel is expected to achieve overall holing-through in July 2026.

The Xichang-Zhaotong Expressway is an expressway connecting Zhaotong City in Yunnan Province and Xichang City in Sichuan Province. It is an important section of the Duyun-Shangri-La Expressway in the National Highway Network Plan (2013-2030). The route has a total length of 184.8 kilometers and a total investment of 31.417 billion yuan. The entire line is built to a four-lane expressway standard with a design speed of 80 kilometers per hour.

After completion and opening to traffic, the route will connect Jinyang South to Panzhihua, north to Yibin, east to Zhaotong, and west to Zhaojue to link with Leshan, and directly reach Shangri-La via Xichang. It will further strengthen the connections among the Chengdu Economic Zone, the South Sichuan Economic Zone and the Panxi Economic Zone, effectively shorten travel time and distance, and facilitate public travel. It is of great significance for consolidating the poverty alleviation achievements in the ethnic minority areas of Liangshan Yi Autonomous Prefecture, comprehensively advancing the rural revitalization strategy, promoting external cultural exchanges and integration, and improving the expressway network in Southwest China.