Q49
What caused delays in the Metro tunnel beneath the Hooghly River in Kolkata?
A.
Sandstone aquifers
B.
Basalt intrusions
C.
Water-bearing alluvial silt
AnswerD.
Seismic zone regulations
Answer: Option C
Solution
Answer: Option C
Solution:
The tunnel passed under the Hooghly River through water-bearing alluvial silt, leading to water ingress and requiring specialized TBMs and grouting.