Wednesday, June 2, 2010

Nothing bad's happened at Niagara Tunnel

May 29th 2010 -

The TBM is still undergoing scheduled maintenance and is not expected to begin mining until June 20th. The first of two arch forms has been moved into position just inside the tunnel entrance.

On Thursday May 27th, the first concrete pouring on the arch form bay (12.5 meters) took place. The two arch forms are designed to take turns pouring every other section in succession. The arch forms when fully functioning will attain an average rate of 21 meters per day.

Work continues on the new air vent shaft. The maximum outer diameter of the shaft is currently being drilled. Before this vent shaft becomes fully functional it will need to be lined and grouted. In addition, the Invert Carrier will have to pour concrete beyond the location of the adit.

Work on the Invert Carrier resumed this past week.

Work on the Restoration Carrier continues reinforcing and reshaping the crown of the tunnel. Shotcrete spraying continues in multiple 400 millimeter layers to reshape the crown damaged from previous overbreak.


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