1. Applicable engineering is different. TBM is used for hard rock and shield machine is used for excavation of soil layer.
2. The two tunnels, balance, and support systems are different.
3. TBM is more advanced and more complex than shield technology.
4. The working environment is different. TBM is a hard rock roadheader. It is generally used in mountain tunnels or large water diversion projects. The shield is a soft soil roadheader, mainly urban subways and small pipes.
The earth pressure balance shield machine mainly uses tunneling of soft soil and cohesive soil. It has the characteristics of fast excavation speed and risk of surface settlement. Because the excavation in the soft formation, the soil around the hollow section will quickly sink and sink, so the earth pressure balance shield machine has a strong shield to protect the internal mechanism. Hard rock tunneling TBM is built in hard rock, and the hollow section structure is stable, so TBM does not need long shield shell protection. When a tunnel-type hard rock roadheader is used for tunnelling, the rotating cutterhead with the hob is placed against the face of the hand. Due to the rolling of the hob, the gravel, so-called "clusters", is cut from the rock mass. Come down. The cuttings are caught by the side shovel mounted on the cutter head. While the cutter head is rotating, the cuttings slide down to the center of the machine by gravity through the slag sump, and then fall through the funnel-shaped slag ring onto the main belt conveyor. At the end of the main belt conveyor, the cuttings are eventually transported out of the tunnel by the rear matching belt conveyor or transport vehicle.
Advantages of TBM:
Hard rock TBM is suitable for hard rock excavation in mountain tunnels. Instead of the traditional drilling and blasting method, under the same conditions, the excavation speed is about 4 to 10 times that of the conventional drilling and blasting method, and the best daily footage can reach 150 m. High quality, safety, economy, environmental protection and labor protection.