Core Points - The Sichuan Yibin to Panzhihua Expressway's key project, the Xiejiawan Long Gas Tunnel, achieved dual-track completion on September 27, 2023, laying a solid foundation for the section's completion by 2026 [1][3] Group 1: Project Details - The Xiejiawan Tunnel is located in Yibin City, Sichuan Province, with a total length of 4,295 meters and a maximum depth of 712 meters, making it the longest tunnel in the Yibin section of the expressway [3] - The construction faced significant challenges due to the need to traverse poor geological conditions, including coal strata and karst development zones, as well as difficult material transportation [3] - The project team implemented a "no fire" process for gas control, utilized advanced geological prediction methods, and adhered to principles of short advance, weak blasting, strong support, and rapid closure during construction [3] Group 2: Project Specifications - The Yibin to Panzhihua Expressway has a total length of 446.36 kilometers, designed to a dual four-lane standard with a speed limit of 80 km/h [4] - The expressway will connect with the completed G4216 line and consists of three construction segments: from Ping Shan New City to Jinyang, Jinyang to Ningnan, and Ningnan to Panzhihua [4] - Once completed, the expressway will end the history of no expressway access for the counties of Leibo, Jinyang, and Butuo in Liangshan Prefecture [4]