FEATURE
an occurrence is not designed for and
is considered unacceptable and requires
remediation.
The condition of the ground around
even a stable hole is such that the excavation
results in a reduction in lateral stress.
This reduction occurs as the soil relaxes
radially inward and arching forms in the
tangential direction around the opening,
as illustrated in Figure 5. The arching
is the key to the stress relief, allowing a
minimal outward radial stress to support
the hole; this small supporting stress is
provided by the soil-filled augers or the
support fluid or the casing.
As a result of this relaxation, it is not
uncommon that the soil around a drilled
pile might undergo a reduction in resistance
as measured in an in-situ test, as
demonstrated by data shown by Bottiau
(2014) on Figure 6. These CPT soundings
were made at the locations of two
24-inch diameter CFA piles in medium
dense sandy soil at a site in Belgium. The
blue lines represent the cone tip resistance
at each pile location prior to pile
installation, and the green lines represent
the cone tip resistance measured at a
distance less than a foot away after the
AMERICAN SpiralWeld Pipe, with
plants in South Carolina and Michigan,
has been delivering solutions to the
foundations industry for decades. Pipe
is available up to 80 feet in length with
a variety of coatings and fabrications.
Whatever the job size – up to 12 feet
in diameter and thicknesses up to one
inch – we can handle it.
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Figure 5: Reduced horizontal stress around a hole associated with arching
Piling Pipe from AMERICAN
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Contact:
Mark Gwynn, Manager, Industrial Sales
205-246-2802
mgwynn@american-usa.com
EOE/Vets/Disabilities
DUCTILE IRON PIPE FLOW CONTROL INTERNATIONAL SPIRALWELD PIPE STEEL PIPE
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