China Opens Tianshan Shengli Tunnel as World's Longest Expressway Underground Passage

The Tianshan Shengli Tunnel has officially become the longest expressway tunnel in the world following the completion of its primary construction phase in the Xinjiang Uygur Autonomous Region. Stretching 22.1 kilometers, the structure forms a critical section of the Urumqi to Yuli Expressway. This project overtakes the previous record held by the Yamate Tunnel in Japan, which measures 18.2 kilometers.

Construction crews utilized a triple-shaft excavation method to manage the immense scale of the project. This involved two main tunnels dedicated to outbound and inbound traffic, alongside a central service tunnel. The central passage served as an entry point for Tunnel Boring Machines, allowing engineers to create additional working faces and accelerate the timeline for the main thoroughfares.

The tunnel traverses the Tianshan mountain range, a region characterized by complex geological conditions and high altitudes. Engineers encountered significant tectonic activity and high rock pressure during the drilling process. To address these challenges, specialized heavy machinery was deployed to maintain structural integrity while navigating varying rock densities and underground water sources.

Beyond its technical specifications, the tunnel alters the regional logistics network by providing a year-round passage through the mountains. Previously, the route over the Tianshan range was subject to seasonal closures due to heavy snow and ice. The new infrastructure reduces the travel time between Urumqi and Korla from seven hours to approximately three hours, creating a more reliable connection for heavy goods transport and passenger vehicles.

The project is part of a broader expansion of the national expressway network in western China. By bypassing the steep, winding roads of the mountain passes, the tunnel improves safety for motorists and reduces the fuel consumption associated with high-altitude climbs. Final testing of the ventilation and lighting systems is expected to precede the full opening of the route to public traffic.