installation interval to confirm capacities in both compression
and tension applications. Monitoring and
recording the installation torque is the main portion of
the quality assurance/quality control process required
to ensure capacity of the helical piles or anchors. The
greater the resistance (torque) during installation, the
denser the soil that is being penetrated and the higher
the load carrying capabilities of the pile.
“Helical piles are an end-bearing deep foundation
system that has applications in compression, tension and
lateral load situations,” said Dino Vito, president of EBS
Geostructural, Inc., in Breslau, Ont. “By applying torque
to the shaft, this action installs the helical pile with minimal
displacement or disturbance.”
This is beneficial because no vibrations or spoils are
created during installation. Loads are transferred down
the shaft to the helical bearing plates and the minimallydisturbed
soil beneath or above each plate.
Vito, who joined EBS in 1995, says the Kitchener-area
company started using helical piles in the early 1990s.
Initially, they were used to support residential structures
that had settled.
“Then we started using them more for new construction,
supporting residential units three storeys and less,”
he said. “Here at EBS, we’ve completed over 450 load
tests on helical piles for compression and tension. As we
built the database on our website (accessible to anyone) of
the capacities and what we can achieve with helical piles,
we were able to prove to the industry that they can be
used for higher loads.”
EBS Geostructural is a design-build deep foundation
construction company specializing in helical piles,
micropiles and geotechnical grouting for industrial, commercial
and institutional applications. Vito says that EBS
typically uses grouted square shaft helical piles and often
designs for an Ultimate Limit State capacity of 1,000 kilonetwons
(225 Kips) or greater per helical pile.
“You’re not stripping the soil; you’re slicing through
it. You still have the bearing capacity of the denser soil
underneath, as it is minimally disturbed. A high water
table does not affect these piles during installation.
Helical piles are a versatile tool in the deep foundation
industry,” said Vito.
In 2019, EBS was involved in building one of the tallest
structures on helical piles: One Richmond Row in
London, Ont., a 32-storey residential tower. With a high
water table, deep loose sand deposits and limited access
for construction equipment, helical piles were selected
over driven piles because of the potential vibration issues
to surrounding structures, not to mention the noise disruption
in the city’s downtown core.
EBS performed extensive compression and tension
load tests at the London site to determine the load capacities
and to value engineer the foundation with the owner
of the tower.
“We have been brought into more projects because
helical piles can be cost effective for developers in certain
situations,” said Vito. “Helical piles are good when it
comes to projects where there is some difficulty, where
access is limited or the water table is high. We’ve worked
EBS installs Chance square shaft helical piles at the Strange Street Pumping Station in Kitchener,
through a layer of cobbles that round shaft helical piles were unable to penetrate
18 Issue 4 2021 www.pilingcanada.ca