Sunday, June 14, 2009
Niagara TBM at Full Speed
As of June 13th 2009
continuous roof line over-break of 60 centimeters
average 13 metres per day
It's just as the blogroom predicted, no overbreak, and speeds approaching theoretical maximum. Boy, is this going to be a good section of tunnel for our giant rock mechanics experiment. God knows we have enough sections of the other type...
Probably another week or two of this great stuff, and then we enter TBM Horror - a mixed face! Since the cost of this tunnel will far exceed any water income, we should celebrate what it is - the worlds most elaborate underground laboratory. I really wish they would do some more measurements, though.