Recently, the Daxiangshu Tunnel on the Muyuan Expressway, invested in and constructed by Yunnan Communications Investment Group, was successfully holed through on both tubes.

The Daxiangshu Tunnel is the longest tunnel on the Muyuan Expressway, with the right tube 5,675 meters long and a maximum burial depth of 627 meters, and the left tube 5,631 meters long and a maximum burial depth of 633 meters. The tunnel is located in a tectonically denuded mid-mountain river valley slope area and the core area of the Jinsha River system, where the terrain is steep and the valleys are deeply incised. The strata are dominated by soft to semi-hard rocks such as argillaceous sandstone and sandy mudstone, and the site presents a three-dimensional water hazard pattern of "a reservoir pressing down from above, streams seeping in from the sides, and an underground river lurking below." The surrounding rock is extremely unstable and prone to sudden collapse; groundwater consists mainly of bedrock fissure water andstructural fissure waterand short-term water inflow may occur in local sections; in the portal section, reverse-slope construction produces large water inflow, with peak daily drainage comparable to that of a small reservoir. Construction is technically difficult and costly.

Faced with extremely complex construction conditions, the project company, together with all participating units, took as its core principles "weak blasting, short advance, strong support, early sealing, and frequent measurement," innovatively optimized the construction organization design, adopted detection methods such as the transient electromagnetic method and the high-density electrical method, advanced hydrogeological drilling and forecasting, and technologies such as "advanced grouting for water plugging + staged drainage," thereby minimizing safety hazards to the greatest extent and minimizing the impact of construction on the surrounding environment.

The successful holing-through of both tubes of the Daxiangshu Tunnel has laid a solid foundation for the full opening of the Muyuan Expressway. Next, the project company will continue to carry forward the spirit of the "Communications Investment Iron Army," advance the remaining works at full speed, ensure the project is completed on schedule, and help boost local economic development.