The construction technology of wet sprayed steel fiber reinforced concrete (SFRS) has developed rapidly abroad in recent years, and it will be the development direction of shotcrete in the future, with a trend of completely replacing the traditional hanging steel mesh dry shotcrete. The application of wet sprayed steel fiber reinforced concrete in China has gradually increased, and some attempts have been made to use wet sprayed steel fiber reinforced concrete as permanent lining (Norwegian method), which have achieved good results and preliminary experience. The Taihang Mountain Extra Long Tunnel is located between Xiaocaoxia Station and Mengxian Station on the Shitai Passenger Dedicated Line, passing through the main peak of the Taihang Mountain Range, Yuexiao Mountain. The tunnel has a large burial depth of 445m and is designed as a double tunnel single track tunnel with a distance of 35m between the two lines. The total length of the tunnel is 27839m, which is currently the Changshanling Tunnel designed in China. The surrounding rock mass at the entrance of the tunnel is broken, and the conditions for crack development are poor. Wet sprayed steel fiber concrete is used for initial support in the design. The adoption of this technology in the construction process involves many aspects such as machinery, concrete materials, construction organization and management, support theory, comprehensive cost accounting, personnel training, environmental protection concepts, etc. Therefore, the promotion and application of wet shotcrete technology is a systematic project, and it is necessary to correctly understand the dialectical relationship between construction period, cost, quality, and safety.

Wet sprayed steel fiber reinforced concrete is suitable for temporary support, initial support, permanent support or lining in tunnel and underground engineering, high slope and deep foundation pit construction. It can also be applied to concrete structural parts with special requirements such as erosion resistance, corrosion resistance, earthquake resistance and explosion prevention, as well as repair and reinforcement of existing concrete facilities and surface protection.