SMART WAY TO DO JOB CUTS TIME IN HALF
When Kootenay
Industrial Contractors, Ltd., bid on the job to remove a 16-in.
thick layer of deteriorating concrete from the face of three
steep spillways at a hydroelectric dam, general manager Sante
Pulice figured he had two choices:
- His crews could do the job the hard way-standing on
platforms and wrestling with jackhammers.
- Or they could do it the smart way-using compact excavators
equipped with hydraulic breakers.
He chose the
smart way. That cut the time required by at least 50 percent.
This was part of a project to reface three spillways, each
34-ft. wide and 100- to 120-ft. long with a 60-degree slope, at
the Brilliant Dam on the Kootenay River near Castlegar, B.C. The
demolition phase required Pulice's crews to remove 785 cu. yds.
(600 m3) of concrete. They used Bobcat® equipment-four 331
excavators with 2560 and 2570 hydraulic breakers. The Bobcat
products came from Trowelex Rentals and Sales, Ltd., the Bobcat
dealer in Castlegar.
"We finished the concrete demolition in six weeks," Pulice
reports. "It would have taken 18 men with jackhammers probably
12 to 14 weeks to do the job."
Excavators Work From Platforms
A pair of the excavators each worked from a timbered steel-beam
platform. A 40- ton crane loaded the excavators on the
platforms. Working from the top of the spillway down, each
platform was lowered and raised by 10-ton air winches. Once in
place, the platforms were secured by threaded steel bolts,
anchored 4-ft. deep into the spillway face.
"The excavators worked eight hours a day," Pulice says.
"Each machine removed from .7 to 1 cu. yd. (.5 to .75 cu. m) of
concrete per hour, which met our expectations."
Long, narrow buckets on the platforms collected the concrete
as it was removed, protecting the river from debris. When full,
a crane lifted the buckets, dumping them into trucks for
removal. The crane was also used to lower buckets of fresh
concrete for refacing the spillways.
Safety, of course, was a key concern.
"We always had to be aware that we were working at an
operating power-generation facility," he says. "Whenever our
guys were walking on the platforms or on the spillways they were
secured by safety lines from the top of the dam."
Once all the concrete was removed, a rotary air drill bored
holes into the spillway face to mount anchor bolts for the
rebar, prior to pouring new concrete.
"It was a tough project, but the Bobcat excavators made it a
lot simpler," Pulice says. "They worked very well. Unlike men
who get tired as the day goes on, the excavators don't. So
production stays up all day long."
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