Recently, after 800 days of unremitting efforts, the control project of Linjin Expressway - Shizhushan Tunnel, which was constructed by China Railway No. 1 Bureau No. 5 Company, has been completed. So far, the builders have conquered the most complex karst tunnel group in Zhejiang Province, marking the completion of the last main project of the Linjin Expressway and entering the construction stage of the road surface and ancillary projects in an all-round way.

Linjin Expressway is located in the hilly and mountainous areas of western Zhejiang. There are 30 tunnels on the whole line, passing through the Yaolin Wonderland with dense karst caves and crossing the Tianmu Mountains with dense faults. Among them, the Shizhushan Tunnel, Huxitai Tunnel and the Yangtiandong Tunnel in the adjacent bidding section, which were built by the five companies, are known as ""Due to the convergence of various problems such as large-scale caverns, water intrusion and mud intrusion, and carbonaceous mudstone deformation. Geological Museum” has become the most complex karst geological tunnel group in the history of expressway construction in Zhejiang Province.

The Shizhushan tunnel that has been penetrated this time is a typical example of this most complex karst tunnel group. The tunnel is located near the Yaolin Wonderland Scenic Spot in Tonglu County, Hangzhou City. It is a two-way split tunnel. The left hole is 273 meters long and the right hole is 297 meters long. "Short tunnels like this can usually be penetrated in about 3 months, but we have been working for more than 2 years." The relevant person in charge of the project department introduced that in order to prevent the surrounding rock from being unstable and collapsing due to excavation, the construction team every day Only about 50 cm can be excavated and reinforced in time. "It can be said that the tunnel is 'carved' by the workers little by little."

The total length of Linjin Expressway is about 85.5 kilometers. It adopts the standard of two-way four-lane expressway and has a design speed of 100 kilometers per hour. As the last disconnected expressway between Zhejiang and Anhui provinces, after the completion of Linjin Expressway, it will further improve the expressway network between Zhejiang and Anhui provinces and the Yangtze River Delta, and strengthen the economic radiation of the Yangtze River Delta to the surrounding areas.Editor/Ma Xue