Tunnels refer to engineering buildings buried in the ground and are a form of human utilization of underground space. Tunnels can be divided into traffic tunnels, hydraulic tunnels, municipal tunnels, mining tunnels, military tunnels, etc. Traffic tunnels are the type of tunnels most closely related to human social life and production activities. They are mainly used for the passage of people, motor vehicles, trains, ships, etc. According to their functions, they are divided into road tunnels, railway tunnels, urban underground railway tunnels, and shipping tunnels. Tunnels and pedestrian subways, etc. Read More