The working principle of shield machine

shield machine

The working principle of the shield machine is that while the soil is being excavated, the cylindrical steel member is propelled forward along the axis of the tunnel. The shell of the cylinder assembly is a shield, which temporarily supports the excavated unlined tunnel section, bears the pressure of the surrounding soil layer, and sometimes also bears the pressure of groundwater to keep the groundwater outside. Excavation, dumping, lining, and other operations are carried out under the cover of the shield.

1. Shield machine tunneling

working principle of shield machine

The hydraulic motor drives the cutter head to rotate, and at the same time, the shield machine driving cylinder is turned on to push the shield machine forward. With the forward drive of the driving cylinder, the cutter head continues to rotate, and the cut muck is loaded into the soil bin. At this time, the screw conveyor starts to unload the cut muck to the belt conveyor, and then the belt conveyor transports it to the soil box of the muck truck and then transports it to the ground through the shaft.

2. Control the amount of soil discharge and the speed of soil discharge during excavation

when the ballast soil in the soil bin and screw conveyor accumulates to a certain amount, the resistance of the intercepted slag on the excavation surface to enter the soil bin through the knife groove increases. When the earth pressure of the soil bin is balanced with the earth pressure on the excavation surface and the water pressure of the groundwater, the excavation surface can be kept stable, and the corresponding ground part of the excavation surface will not collapse or expand. At this time, as long as the amount of muck conveyed from the screw conveyor and the soil bin and the cut-off muck are kept in the soil bin.

3. Segment assembly

After the shield machine is driven for one circle, the operator of the assembly machine manually operates the assembly machine to assemble the single-layer lining segment, and the tunnel can be formed at one time.

GloryRail is a manufacturer specializing in rail systems for many years. We provide steel rail materials, rail accessories, steel sleepers for shield machines, etc. required for subway tunnel construction. If you have any questions in this regard, please feel free to consult GloryRail.