Core Insights - The construction of the Xichang–Shangri-La Expressway has entered a comprehensive construction phase with the completion of the underground interchange tunnel [2][4] - The project is recognized by WRCA as the "world's largest underground interchange for mountainous expressways" currently under construction [2] - The expressway features nine super-engineering projects, each presenting significant construction challenges [3][7] Project Overview - The Xichang–Shangri-La Expressway was initially planned in 2011 but faced delays due to high construction costs and difficulties in attracting investment [4] - The project was revitalized after being included in the National Highway Network Planning (2013-2030) [4] - As of 2022, the project has officially commenced construction, with large-scale operations currently underway [4] Engineering Challenges - The expressway has a bridge-tunnel ratio of 73.4%, comprising 131 bridges and 32 tunnels, with a total estimated investment of 58.738 billion yuan and a per-kilometer cost of approximately 25.1 million yuan [5] - The Lugu Lake Grand Bridge is a key feature of the project, recognized for having three world records, including the largest span of a cable-stayed bridge in mountainous regions [5][6] Innovative Solutions - The design of the Lugu Lake Grand Bridge incorporates a U-shaped tunnel anchor to address geological challenges, reducing concrete usage by 20% and enhancing stability [9] - The bridge's construction utilizes a steel pipe and concrete composite structure for improved wind and seismic resistance, increasing performance by approximately 30% compared to traditional designs [9] Technological Advancements - The project employs advanced construction techniques, including a specialized TBM (Tunnel Boring Machine) for complex geological conditions, reducing the construction period from seven years to four years [10] - The project management utilizes AI and drone technology for real-time monitoring and data management, enhancing operational efficiency [10] Regional Impact - Upon completion, the Xichang–Shangri-La Expressway will integrate with several other highways to form a comprehensive transportation hub in Liangshan Prefecture [11] - The current construction phase is part of a broader initiative to enhance highway infrastructure in the region during the 14th Five-Year Plan period [11]