Monday 28 November 2011

Drill Bits and Dynamite Part Seven...Sea to Sky Cut 9...Big, Bad and Ugly Cut 9

Cut 9, on the Squamish highway project was legendary before we even touched it. Steep, high, covered in trees and pretty much looming over the existing roadway, it was an intimidating sight. Approximately 185,000 to 200,000 cubic meters of rock needed to be removed, while keeping the highway and railroad far below, intact.

Cubic meters of rock...to put it into perspective. envision a two story, flat roofed house. 10 meters long ( 33 ft +/- ) and 10 meters wide, 10 meters tall...a cube 10x10x10 meters...that would be 1000 cubic meters.

A highway legal dump truck with tandem axles can haul about 8 cubic meters of rock...maybe more maybe less...but let's go with 8.

The point being...we had to safely and efficiently remove the equivalent of 200 two story houses, or 25,000 dump truck loads of rock from a ledge that was perched 100 meters above the existing highway.

We tried to get loggers in before we started....the heli-loggers wanted the highway closed while they worked...that wasn't gonna happen. Mini-tower guys wouldn't return calls...even at the promise of what ever hourly rate they chose. We ended up building the goat trail and then skidding and hoe-chucking to stock-piles.



When Robin and I came back from photographing Seg 2 and 3...we came upon Tyson and Greg pondering their next move after the road collapsed behind them.....100 meters down to the road...rock wall in front and beside....and a rock slide behind them

That kind of work-site is not for everyone!


This was a fun day for me. I had called Robin for a photo run in the helicopter earlier in the day. He was busy with Hydro, so he sent another guy to take his place. In the mean time, we were short on operators, so I took an excavator up to clear off the road. The guys in the powder truck needed to get as close as possible to the shot. While I was working up there, the helicopter dispatcher phoned to say that the helicopter had been re-routed and would be on-site in 10 minutes. ...So I bailed out of the machine and walked down the trail to my truck. Boogied down the haul road to the landing area and jumped into my waiting ride. As we flew by, on our way to the photo shoot. I snapped a few pics  of my work site.





When we started to blast and remove rock in the area of the "two pole" site, the blasting crew started to be be concerned about the very soft and weathered rock that we were encountering. The rock was peeling off in layers and had very little strength. We said that if the slope needed to be laid back more, now was the time....because later...we won't be able to reach it.
 There were two concerns with this idea. One, was the cost of moving the two pole structure back. Two was the added cost of the extra cubes that would be generated. It was decided by the company and the geo-techs to maintain the .25 to 1 slope, instead of going to .33 to 1...  and use an aggressive bolting program.
If you look just below the two-pole structure, you can see the silver backing plates of dozens of rock bolts...it was later also shot-creted in an attempt to keep the soft rock in place...myself, I really wish that the slope got laid back more









part of the bolted wall fell off, lucky no one was around it when it fell











Digging out from the berm at the bottom of Cut9 to articulating rock trucks. They were permitted to run on the highway during the project




More Cut 9 stories and pics on the way
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