Recently, the Desheng Tunnel, a key and difficult control project on the entire Sichuan-Qinghai Railway line with a total length of 22.923 kilometers, was finally completed after nearly ten years.

The Sichuan-Qinghai Railway is an important component of the Lanzhou-Xining-Guangzhou corridor in China's "Eight Vertical and Eight Horizontal" high-speed rail network, of which the Chengdu-Zhenjiangguan section was completed and put into operation on November 28, 2023. What blocked the last "throat" section of the Sichuan-Qinghai Railway within Sichuan Province was the Desheng Tunnel.

According to reports, the Desheng Tunnel is located in Songpan County, Aba Prefecture, on the northwestern Sichuan Plateau, at an altitude of 2,800 meters, and must pass through three fault zones: the Longmenshan, the Western Qinling, and the Minjiang.

Construction workers persevered for 3,540 days, experiencing strong geological disasters such as the magnitude-7 Jiuzhaigou earthquake, massive landslides, and debris flows. The Desheng Tunnel broke ground in September 2014. During construction, problems such as collapses, mud inrushes, water inrushes, and large deformations occurred more than 300 times, making construction extremely difficult.

According to reports, carbonaceous phyllite is characterized by being fragmented and soft—it collapses at a touch and crumbles at a pinch, turning to mud when it meets water. During construction, sections that had already been hardened and supported kept deforming and required constant reworking. Through arduous practice and theoretical summarization, the project team finally grasped the mechanisms generating large deformations, the deformation patterns, and construction techniques, and patiently completed the "surgical challenge" of the "throat" section of the Sichuan-Qinghai Railway.

According to the design plan, the main line of the Sichuan-Qinghai Railway is approximately 836 kilometers long, with a design speed of 200 kilometers per hour, and is a national Class I double-track railway.