Squeezing of Underground tunnels

During my brief time as a mining engineer I've often wondered what the worst possible scenario could be for a tunnelling project and the point at which you realise that you've been caught up s*** creek without a paddle. This got me thinking back to the topic of tunnel squeezing and cases of tunnelling projects which were plagued by this problem. For readers who are unfamiliar with squeezing I'd like to refer you to Evert Hoek's (2000) lecture on tunnelling in weak rock entitled "Big Tunnels in Bad Rock".


This post is largely born out of my interest in excessively squeezed tunnels and I still consider this to be the most spectacular and impressive of all failures - basically I just thought it would be cool to put a few photos up of what can go wrong when squeezing takes hold of a tunnel....

Roof squeezing during hydroelectric project in Nathpa Jhakri, India. After Hoek (2000).

Squeezing of Mucha tunnel in Taiwan. After Hoek (2000).

Excavation of Metro station tunnel - Athens, Greece. After Hoek (2000)

Tunnel heave: Bolu tunnel, Turkey

Base displacement: Bolu tunnel, Turkey