QUZHOU, May 5 (China News Service) — Qian Chenfei, Lin Yongyang: During the May Day holiday, the Shizishan Tunnel of Section III of the first phase of the Quzhou-Lishui Railway project, constructed by China Railway No. 10 Engineering Group, was successfully holed through. This is the first tunnel over one kilometer in length to be completed within the section.

It is reported that the Shizishan Tunnel has a total length of 1,315 meters and a maximum burial depth of 108.5 meters. The tunnel body runs through Shizishan Mountain and is a single-tube, double-track tunnel designed for a speed of 200 km/h. The tunnel contains a total of 8 fractured surrounding rock zones. Among them, the local terrain at the exit is poor, with dense surface vegetation and dangerous rocks that are difficult to see. Above the north side of the entrance and the main tunnel, there are residential buildings of 1 to 3 stories with reinforced concrete frame structures. This section has a burial depth of 20 meters and a straight-line distance of 143 meters from the tunnel portal. The safety risks are numerous and complex, and the construction difficulty is relatively high.

In the face of various construction challenges in the early stage, the project department carried out advanced geological forecasting, used a combination of manual clearing and mechanical excavation to remove dangerous rocks layer by layer and block by block, and coordinated and communicated with relevant local government departments and village committees and conducted on-site surveys to jointly advance land acquisition and demolition work and ensure the prerequisites for tunnel excavation.

The Quzhou-Lishui Railway starts from Qujiang Station on the Hangzhou-Quzhou Railway, passes through five mountainous counties—Qujiang, Longyou, Suichang, Songyang, and Liandu—and connects to Lishui Station. It has a total length of 160 kilometers, with 6 stations in total, and a design speed of 200 km/h. After the railway is opened for operation, it will be of great significance for improving the layout of the road network in southwestern Zhejiang, accelerating the development of tourism resources along the line, and promoting economic and social development along the route.