Tunnel boring Machine

1. Unit No. 3
Tunneling
Tunnel Boring Machine
Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423603
(An Autonomous Institute affiliated to sppu, pune)
Department of Structural Engineering
PROF. GUNJAL SACHIN M
ASSISTANT PROFESSOR, STRUCTURAL ENGINEERING
DEPARTMENT

2. Tunnel Boring Machine (TBM)
• Tunnel Boring Machine (TBM) also known as ‘MOLE’.
• It is used to excavate tunnels with a circular cross
section.
• It can bore through anything from hard rock to sand.
• Different types of TBMs are used for different
geotechnology.
• Used as an alternative to drilling and blasting (D&B)
methods and conventional 'hand mining' in soil
• Limits the disturbance to the surrounding ground and
produces a smooth tunnel wall.
• Suitable to use in heavily urbanized areas.

3. Tunnel Boring Machine (TBM)
• Before the advent of TBM the drilling and
blasting was the only economical way of
excavating long tunnels through hard rock,
where digging is not possible.
• Even today, the method is still used in the
construction of tunnels, but the
disadvantage is it disturbance the
surroundings.

5. Advantages
• Higher advance rate
• Continuous operations
• Less rock damage
• Less support requirements
• Greater work safety
• Automated operations

6. Disadvantages
• TBMs are expensive to construct and can
be difficult to transport.
• TBM can not move in backward direction
• Difficult to transport.