The original plan for the five-storey facility (four above
ground, one below) called for a straight shaft and belled
drilled concrete pile foundation. IPS and its engineering
team knew there was water infiltration at the site at a depth
of about 15 metres and had concerns about the water inter-fering
with the formation of the concrete bells.
“When we met with the construction manager, Wright
Construction, they wanted to pick our brain about the best
pile type,” said Cote. “We had to come up with an alternative
that either saved money or was faster, and we did both.
“Our main concern was the schedule. This project had to
be in commission in 18 months, and piling had to be done
prior to finals at the university. So we switched from drilled
cast-in-place concrete piles and proposed driven steel pipe
piles and helical steel screwpiles for the structural piling and
switched the CFA secant wall to driven H-pile soldier piles
with wood lagging for the earth retention.”
IPS arrived on site on Nov. 3, with a deadline to complete
the piling phase of the project by Dec. 8. In total, the company
fielded 19 employees from job start to finish.
The scope of IPS’ involvement included installation of the
shoring wall – with 18 feet of earth to retain, the structural
piling itself and the excavation and construction of the pile
caps, which were 10x10x3 feet thick. Before the company
could begin its work, an overhead walkway had to be removed
to allow access to the site down a 10-foot-wide ramp.
In total, 21 truckloads of pipe and H-beam had to be
craned in to a site where a half-tonne pickup truck could
barely fit. The list of materials for the job included 160 driven
16-inch pipe, each 60-feet long; 125 driven W310x79 50-foot-long
H-piles; and 89 seven-inch by 30-feet long with a 24-inch
helix helical steel screw piles.
Cote says that to make the schedule work, IPS had to
install the structural driven pipe piles from grade.
“They didn’t want to excavate down until we had the piles
in the ground. We fashioned a chaser that was able to drive
the pile 16 feet below grade. We were able to drive every pile
to within three inches of final depth.”
Originally, IPS had proposed a schedule that allowed
for pile driving at night, so the work didn’t disturb classes.
However, a permit dispute meant they subsequently had to
make workday adjustments due to noise by-laws.
“When you’re driving piles at night, you can hear it clear
across the city,” said Cote. “So we got shut down the second
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