On January 19, 2022, after 14 years and more than 5,000 days and nights of hard excavation by the builders, an important part of the China-Myanmar International Corridor, the last unpenetrated tunnel of the Dabao Section of the Yunnan Da (Li) Rui (Li) Railway, the Shanyang Tunnel was obtained. Major breakthrough: The 13-kilometer-long horizontal guide has been completed, and the main tunnel has conquered the last 130 meters of VI-level surrounding rock, and has laid a solid foundation for the completion of the entire tunnel as scheduled.

Shanyang Tunnel is located in Yongping County, Dali Prefecture, Yunnan Province. The main tunnel is 13.3 kilometers long. It passes through the Lancang River fault zone and 6 fault fracture zones in the longitudinal valley of the Hengduan Mountains. The maximum burial depth is 1015 meters. The geological conditions are extremely complex and active. Risk Tunnel. It is the last unpenetrated tunnel of the Dabao section of the Darui Railway, and it is also the last "stumbling block" to realize the opening of the Dabao section of the Darui Railway.

In October 2021, when the tunnel construction reached the remaining 200 meters, it suddenly encountered a rare challenge of grade VI surrounding rock at home and abroad, which made the construction more difficult than expected, cognition and imagination, and the uncertain factors increased suddenly. All have to pay a huge price. In order to overcome the tunnel problem, the railway department, together with experts in the industry and all parties involved in the construction, "consulted the pulse" for the tunnel excavation, and determined the "enhanced version" implementation plan based on the premise of safe advancement, the core of advanced forecasting, and the guarantee of comprehensive policies. .

According to Ding Lei, deputy general manager of the first company of China Railway 23rd Bureau Group, according to the special geology of grade VI surrounding rock, in accordance with the "principles of quick excavation, quick support and quick closure", the weak surrounding rock should be supported and strengthened in advance, and the size of the surrounding rock should be reduced as much as possible. To avoid the risk of slippage, nearly doubled the investment in excavation, slag trucks and other machinery and equipment and construction elements, and launched the tough battle of tunnel construction centered on "anti-slippage, deformation control, and surge prevention" to ensure an effective operation cycle.

The Shanyang Tunnel's smooth lead through this time has proved the geology for the subsequent construction, opened up the biggest "stumbling block" in the construction, and created very favorable conditions for the excavation of the last 130 meters of the main tunnel. Hu Jinxing, a senior engineer at the Dari headquarters of Yunnan-Guangxi Railway Yunnan Company, said.

The Dali-Rui Railway has a total length of about 331 kilometers. After completion, it will end the history of the inaccessibility of trains in Baoshan, Dehong and other ethnic minority areas in Yunnan. By then, Dali to Baoshan will be shortened from the current 2 hours to about 1 hour by road, and Dali to Ruili will be reduced from 6 to 6 hours. hours reduced to about 2 hours.Editor/Ma Xue