After the shield machine has dug the soil, where will the soil go out?

After the shield machine finishes digging, the soil will be transported to the outside through the crawler, and the inner wall needs to be reinforced by other means. Shield machine is a kind of tunnel boring machine using shield method. Shield method is the shield of tunnel built (laid) by boring machine (referring to supporting segment), which is different from open excavation method.

The basic working principle of shield machine is that a cylindrical steel member pushes forward along the tunnel axis to excavate soil. The shell of the barrel assembly is a shield, which plays the role of temporarily supporting the excavated unlined tunnel section and bears the pressure of the surrounding soil layer and sometimes the groundwater pressure to keep the groundwater out.

Brief introduction of shield machine.

The excavation amount of shield construction accounts for 45% of the total subway construction in Beijing, and * * * has 17 shield machines for subway construction. Although the cost of shield machine is high, it can improve the efficiency of subway underground excavation by 8 to 10 times.

Moreover, in the process of construction, there is no need for large-scale demolition of the ground, no traffic jam, no noise during construction, no ground settlement and no impact on the normal life of residents. However, the large shield machine has high added value and complicated manufacturing process, and only a few enterprises in Europe, America and Japan can develop and produce it internationally.