On May 20, the No. 2 inclined shaft of the Tongbaiyuan No. 1 Tunnel, the longest tunnel on the entire Yanyu Railway line, successfully broke through and began excavation, marking a new stage in the project's construction.

Construction workers celebrate at the site

The Yanyu High-Speed Railway Section 5, constructed by China Railway 20th Bureau Group Fourth Engineering Co., Ltd., is located in Yanchuan County, Yan'an City and Qingjian County, Yulin City, Shaanxi Province, with a main line length of 16.87 kilometers and a bridge-tunnel ratio of 100%. The controlling and major difficult project is the Tongbaiyuan No. 1 Tunnel. The tunnel has a total length of 14,616 meters, predominantly through Class III, IV, and V surrounding rock. The tunnel passes through loess ridge and gully terrain, where unfavorable geological conditions such as loess landslides and surface slumping develop on both sides of the gullies, posing high construction safety risks and great organizational challenges.

The Tongbaiyuan No. 1 Tunnel has two inclined shafts in total, of which the No. 2 inclined shaft is 649 meters long, adopts a two-lane cross-section, and is designed and constructed as a permanent works. The inclined shaft working face is responsible for 5,200 meters of the main tunnel, serving as the secondary critical route of this section; its construction progress directly affects the achievement of the section's schedule targets.

To ensure smooth tunnel construction and safe shaft breakthrough, the project department, on the one hand, strictly implemented the management requirements of the construction unit, carried out safety grid management, made every effort to ensure that personnel, machinery and equipment, and raw materials met construction requirements, and overcame difficulties such as strong resistance in constructing access roads and power shortages, thereby ensuring the smooth breakthrough of this inclined shaft. On the other hand, it repeatedly coordinated with the owner, design, and supervision units to conduct on-site surveys and on-site verification of construction drawings, carefully planned safety measures and construction schemes, and carried out pipe-roof construction and slope protection at the portal, providing safety guarantees for construction.

Construction site

It is understood that the Yanyu Railway is an important component of the Baotou-Yinchuan (Hainan) Corridor in the national "Eight Vertical and Eight Horizontal" high-speed rail network and of Shaanxi Province's "rice-shaped" high-speed rail network. Once completed, it will be of great significance for promoting coordinated regional development and improving the national comprehensive three-dimensional transportation network. At that time, it will end the history of no high-speed rail service in the Yulin area and achieve Shaanxi Province's goal of high-speed rail access in every city.

Next, all construction personnel of the project department will continue to innovate processes, optimize construction schemes, advance refined project management, safeguard the safety and quality bottom line and red line with high standards and strict requirements, and strive to complete all annual targets and tasks.