Q19
What was the main cause of tunnel face collapse in the Heathrow Express Rail Link project?
A.
Water ingress into clay
B.
Lack of grouting
C.
Excavation in London clay without support
AnswerD.
Overcutting
Answer: Option C
Solution
Answer: Option C
Solution:
The collapse occurred due to unsupported excavation in London clay, leading to loss of face stability. It emphasized the importance of real-time monitoring and pre-support measures.