In Gannan in October, snowflakes have already fallen from Mount Ayi at an altitude of 3000 meters. In the depths of the mountain, a different scene unfolded: headlights piercing through the darkness, the roar of rock drills echoing on the narrow palm face, and rows of dump trucks slowly driving out of the cave entrance. On October 19, 2026, the main tunnel excavation of the Ayishan Tunnel on the Xicheng Railway, constructed by China Railway 14th Bureau, successfully broke through the 4000 meter mark, laying a solid foundation for the subsequent tunnel connection.

A tough battle deep in the plateau

The Ayishan Tunnel has a total length of 5093 meters and is a single tunnel, double track, two-level high-risk tunnel. It is located in a high-altitude mountainous area at an altitude of about 3000 meters, with harsh climatic conditions and complex geological structures, with a maximum burial depth of 870 meters. The tunnel passes through multiple sections of soft rock with large deformations, and the rock mass inside the tunnel is broken and the stability of the surrounding rock is poor. During the construction period, it faces multiple safety tests such as rock deformation, and the construction task is arduous and heavy. Under the conditions of extreme cold and oxygen deficiency, mechanical efficiency decreases and personnel physical energy consumption intensifies. Long distance material transportation and logistical support are also under heavy pressure. Every meter of excavation is a competition with the mountain.

Give Dashan a physical examination

Faced with invisible risks, the project team puts their efforts at the forefront. During the construction process, advanced geological prediction technologies such as geological radar and TSP are comprehensively utilized, combined with intelligent means such as 3D laser scanning and automatic monitoring and measurement of surrounding rock, to predict the condition of the surrounding rock ahead in advance, strengthen dynamic monitoring throughout the entire process, and dynamically adjust excavation parameters and support plans based on data. The risk control ability is significantly improved. At the same time, new intelligent equipment is used to comprehensively strengthen the safety control of operations, ensuring the safe and high-quality excavation of tunnels. The invisible interior of the mountain is being traced layer by layer.

Connecting Northwest and Southwest

The progress of Ayi Mountain is a microcosm of the overall battle against the Xicheng Railway. This railway starts from Xining Station in Qinghai, passes through Haidong, Huangnan, Gannan in Gansu, passes through Aba in Sichuan, and finally connects to Chengdu East Station. Recently, the longest tunnel in the Sichuan section has been successfully connected, with 11 out of 14 tunnels already connected; Nodes such as the Ge'er Tunnel and the Zhaxilong Tunnel in Gansu have also made consecutive breakthroughs. During construction, ecological protection measures will be implemented simultaneously, with the removal of native grass for centralized maintenance and backfilling, closed-loop sewage treatment, and reserved channels for wildlife migration and animal husbandry, allowing the project to coexist with the plateau ecology.keywords:Engineering infrastructure

The Xicheng Railway is an important component of the Lanxi Guangzhou Passage in the national eight vertical and eight horizontal high-speed railway network. After completion and opening to traffic, it will further strengthen the connection and communication between the Lanzhou Xining urban agglomeration and the Chengdu Chongqing urban agglomeration, promote the interconnection between the Silk Road Economic Belt and the Yangtze River Economic Belt, and end the history of no railway in the Gannan region. At that time, the travel time from Xining to Chengdu will be compressed to about 4.5 hours, and it will only take about 2.5 hours from Chengdu to the Ruoergai Grassland. This high-altitude road has profound significance in promoting regional economic and social development, facilitating travel for people along the route, and assisting rural revitalization.Editor/Yang Meiling