TBM, or Tunnel Boring Machine, is a large, specialized machine used to excavate tunnels through various types of soil and rock. It operates by rotating a circular cutting head that grinds away material, allowing the machine to advance forward. TBMs are commonly used in construction projects, such as subways, water tunnels, and underground utilities. These machines can vary in size and design, depending on the specific project requirements. TBMs are equipped with systems to remove the excavated material and support the tunnel structure as it progresses. Their use helps minimize surface disruption and can be more efficient than traditional tunneling methods.