Q171
In the Marmaray Tunnel (Turkey), a significant design challenge was:
A.
Mountain tunneling
B.
Karst formations
C.
Undersea pressure
AnswerD.
Permafrost
Answer: Option C
Solution
Answer: Option C
Solution:
The Marmaray Tunnel crosses the Bosphorus Strait. The main challenge was undersea pressure at depths of up to 60 meters, requiring specially sealed tunnel segments.