Xi-Yu High-Speed Rail Tunnel Breaks Through in China

Construction crews on the Xi’an-Chongqing high-speed railway (Xi-Yu HSR) achieved a major milestone on June 23, 2026, as the Beiping Tunnel broke through in Chongqing Municipality. The 7,582-meter tunnel, located in Chengkou County, represents a critical step forward in one of China’s flagship infrastructure projects under the nation’s “Eight Vertical and Eight Horizontal” high-speed rail network. This network, which forms the backbone of China’s ambitious railway expansion, connects major economic corridors across the country.

A Complex Engineering Feat

Designed by China Railway Eryuan and constructed by China Railway 12th Bureau, the Beiping Tunnel presented formidable geological challenges. With a maximum burial depth of 765 meters, the tunnel’s path cut through alternating layers of soft and hard rock, creating risks of bedding deflection, rockburst, and low-level gas accumulation. These conditions required constant adaptation from the engineering team.

To overcome these obstacles, the project team deployed an array of advanced detection technologies, including geological radar, TSP advanced forecasting, horizontal drilling, and 3D laser scanning. These tools enabled real-time assessment of changing rock conditions and dynamic optimization of construction plans. The combination of multiple sensing technologies allowed engineers to predict hazardous zones before excavation reached them.

Safety was paramount throughout the operation. According to China News Service, the team implemented a dual prevention and control system combining “intelligent monitoring + manual inspection,” with 24-hour continuous surveillance and dedicated ventilation equipment to maintain safe working conditions. This approach proved essential given the low-level gas risks present in the tunnel.

Progress on the Kang-Yu Section

The Beiping Tunnel is part of the 478-kilometer Kang-Yu section of the Xi-Yu HSR, which runs from Ankang West Station in Shaanxi Province through Chengkou County (Chongqing), Dazhou and Guang’an (Sichuan), and Hechuan and Beibei districts before reaching Chongqing West Station. The Xi-Yu HSR is being built in two phases: the Xi’an-Ankang section and the longer Ankang-Chongqing (Kang-Yu) section.

As of the breakthrough, the Kang-Yu section has completed 56 tunnels and 217 bridge substructures. The project is now entering a critical phase focused on girder erection, station construction, and electrical and mechanical systems installation, as reported by the Xi’an People’s Government. Earlier this year, in January 2026, the Chengkou Tunnel — another key difficult section on the same route — also broke through, demonstrating steady momentum across the project.

Strategic Impact and Travel Time Transformation

The Xi-Yu HSR is expected to open to traffic by 2028. When completed, it will slash travel time between Xi’an and Chongqing from the current 5 hours 4 minutes to approximately 2 hours — a dramatic improvement that will reshape economic and travel patterns across central-western China. The total investment in the project is estimated at approximately 1,557 billion yuan, underscoring its national strategic importance.

Beyond the direct route, the railway will interconnect with the existing Chengdu-Chongqing HSR, Zhengzhou-Chongqing HSR, and the under-construction Kunming-Chongqing HSR. This integration will significantly enhance the high-speed rail network across the central and western regions, linking Shaanxi, Sichuan, and Chongqing into a more cohesive transportation corridor. The Xi-Yu HSR is a key component of the Beijing-Kunming corridor within the national high-speed rail framework.

Broader Infrastructure Momentum

The Beiping Tunnel breakthrough was reported alongside other major infrastructure milestones on the same day, including the main bridge closure of the Qinglongmen Bridge in Zhejiang Province and record export volumes at Qingdao Port’s North Africa route. These concurrent achievements reflect China’s broader push for infrastructure development as part of its “high-quality development” strategy, with the Xi-Yu HSR serving as a flagship example of the nation’s long-term commitment to modernizing its transportation backbone.

What to Watch For

With 56 tunnels now complete on the Kang-Yu section, attention shifts to the remaining engineering challenges, particularly the girder erection and station construction phases. The Xi’an-Ankang section of the line is expected to open earlier, potentially providing a preview of the full route’s benefits. For the Qinba Mountain region — one of China’s less developed areas — the railway promises to unlock economic opportunities through improved connectivity to the major urban centers of Xi’an, Chongqing, and beyond. The project also represents a significant step toward integrating the broader central-western region into China’s rapidly expanding high-speed rail network.