Q28
The term �overbreak� in tunneling refers to:
A.
Collapse of tunnel lining
B.
Excavation beyond design profile
AnswerC.
Overexcavation in soil layers
D.
Lining rebound
Answer: Option B
Solution
Answer: Option B
Solution:
Overbreak is the excess removal of rock beyond the tunnel design profile, often due to blasting or weak zones.