Wednesday, January 14, 2015

Another horrible tunnel job

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Sinkholes are always the tip of the iceberg of ground control problems when tunnelling.  You should be able to cut settlement to zero with a pressure-balancing tunnel boring machine, but that takes money.  Already houses are cracking, and they are complaining about vibrations.  This is going to be a darn train tunnel!

As well, the tiniest bit of settlement makes things a lot worse when the earthquake comes along.

Update:  My one comment of the year has me making an addition.  I will make up a totally fictional situation.

My company Cheapnsleazy Inc.  has just finished a tunnel that may rhyme with a certain blue pill.  I go to Vancouver, and impress them all with my astonishing low price.  I had changed the name because I made a billion on charging extras, and a few people might worry.  I get a crappy old boring machine and paint it up.  What me worry?  I charge ahead at full speed, running a huge ground deficit, with all the portals wide open.  The trees tilt and the buildings crack.  Not me!  Finally I run into big trouble when the sinkholes open up way in front of the machine.  Now is the time for my special trick.  I go to court -- "You didn't tell me that dirt was dirt!"  The judges always go for the contractor.  Another extra billion in the pocket.

Update2:  I am also yelled at because I'm not giving any information.  You will never get information!  The contractor makes a point of never hiring engineers, so he can go full blast with his Stupidity Defence.  And the government people are all under the control of the PR department.

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