Recently, the excavation of Gongbuka Tunnel exit in Kangxin Expressway Section 1 of China Railway First Group successfully exceeded 2000 meters, and the project construction has made critical progress, laying a solid foundation for efficient construction in the future.

The Gongbuka Tunnel has a total length of 8577 meters and adopts a dual tunnel separation design. It is a key control project along the Kangxin Expressway. The total length of the tunnel exit section constructed by China Railway First Group is about 2500 meters, located in an area with an altitude of 3200 meters. The proportion of Class IV and above surrounding rock exceeds 96%, and the rock mass is fragmented, with dense faults and complex geological conditions. During construction, multiple difficulties such as water influx, rock burst, high ground temperature, and large deformation of soft rock were encountered.

In response to complex geological environments, the project department prioritizes safety and quality, strengthens technical support, accurately predicts geological conditions through advanced geological forecasting, dynamically adjusts construction plans based on monitoring and measurement data, and effectively prevents geological disaster risks. Strictly implement the policy of "short footage, strong support, early closure, and frequent measurement", comprehensively adopt advanced support, drilling and drainage pressure reduction processes, successfully solve multiple construction difficulties, and ensure smooth and orderly tunnel excavation. Keywords: Kangxin Expressway, Gongbuka Tunnel, Tunnel excavation

Kangxin Expressway is an important section of the national highway G4218. After completion, it will connect the Yakang Expressway and Chengya Expressway, becoming an important channel to promote rural revitalization and ethnic unity in Ganzi Prefecture. It is of great significance for promoting regional economic and social development, improving tourism and transportation conditions, and deepening cultural exchanges.Editor/Gong Ziwei