the U.S. That said, there is quite a bit of evidence to support
that a type of piling device was used in construction
as early as 5,000 years ago.4
Driven Ductile Iron Piles (DIPs)
One of the most popular types of piles out there, DIPs are
a simple, fast and highly effective low-vibration driven
pile system that uses high-strength ductile iron. Modular
pile sections are connected by a proprietary Plug & Drive
system, eliminating the need for welding and splicing,
while providing a section at the connection, which is
more than twice that of the pipe pile section, resulting
in superior dimensional and driving stability and performance.
With the use of a relatively small excavator
fitted with a high-frequency hydraulic hammer, piles are
installed by driving the pile sections in quick succession
for fast and easy installation with minimal vibrations.
DIPs can be designed and installed for end-bearing and
friction resistance.
End-bearing
In an end-bearing installation, an end cap or driving
point is fitted on the end of the DIP lead section and
successive sections are added as the DIP is installed to
transfer foundation loads through compressible soils or
to fill down to soil that is more suitable for load-bearing
or to bedrock. The pile can be further filled with grout
or concrete, and additional central bars can be added as
needed for additional capacity.
Friction resistance
DIPs for friction resistance are installed with an oversized
conical grout point at the pile base. As the pile is
driven, sand-cement grout is pumped through the pipe
sections and exits through grout ports within the conical
grouting point to fill the void space created by driving the
oversized cap. This process encapsulates the pile in grout
and forms the basis for the grouted bond zone within
the surrounding load-bearing soil to achieve the design
capacity. The system excels in supporting high-capacity
foundations in constrained sites or urban settings where
tight access and low vibration requirements influence
foundation selection. The DIP results in zero waste
onsite, as each cut-off is able to be used as a starter section
for the next pile.
DIP Installation Methodology
End-bearing DIP elements are installed using five-metre
bell-spigot sections and a special driving hammer with
a dry driving shank and a pointed or flat tip. The result
is a high-capacity end-bearing pile system. A concrete/
grout central bar can be added to the inside of the pile to
increase compressive capacity as needed. With many different
sizes and combinations, end-bearing DIP elements
can be installed in many soil types to practically any
depth with full displacement and impact energy; improving
the surrounding soils and reaching end-bearing,
while driving the tip into the end-bearing soils to maximize
both structural and geotechnical capacity. The
end-bearing DIP is superior to helical piles, particularly
in situations that involve quick transitions from very soft
to very hard soils.
Friction resistance DIP elements are also installed
using five-metre bell-spigot sections and a special driving
hammer with a wet driving shank where grout is pumped
continuously through the pile to a tremi-grout head at
the base. A high-capacity friction system results from the
installation, and a central bar can be added to increase tensile
or compressive capacity as needed. Friction resistance
DIP elements can be installed in many soil types with
various diameters and to practically any depth with full
displacement and impact energy, improving the surrounding
soils for high frictional capacity, with more versatility
than helical piles, and less cost than micropiles.
Mark Tigchelaar is president and founder of GeoSolv Design/
Build, Inc., an Ontario-based geotechnical contracting
firm that specializes in providing a range of innovative
foundation solutions for challenging soil sites and provides
clients with the options and advice necessary for them to
make informed decisions about their projects. For inquiries
about this article or ground improvement, reach Tigchelaar
at mark@geosolv.ca.
References
1. http://onlinepubs.trb.org/Onlinepubs/
hrr/1970/333/333-002.pdf.
2. https://www.schoolofpe.com/blog/2017/06/basicprinciples
and-classifications-of-pile-foundations.html.
3. https://www.schoolofpe.com/blog/2017/06/basicprinciples
and-classifications-of-pile-foundations.html
4. https://en.wikipedia.org/wiki/Pile_driver.
TECHNICAL
DUCTILE
IRON PILE
APPLICATIONS
DIPs have numerous applications for foundation
support, including:
• Constrained sites
• Adjacent structures
• Tanks
• Tension anchors
• Wind and solar
• Industrial and floor slabs
56 Issue 4 2021 www.pilingcanada.ca
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