ADVOCACY
but it also required the splice to develop not less than 50% of the
tension and bending strength of the pile. For piles not in seismic
areas, this is an expensive requirement for splices that occur too
deep to have tension or moment loading. A 20-inch OD × 0.500
wall by 240-ft long pipe pile with one splice at 120 feet deep will not
have any tension at the splice. Welding is much more costly than
a drive-fit splice that does not meet the tension requirement. The
ICC committee voted “yea” 14 to 0 but thought our words could be
misconstrued. We revised the “exception” to more precisely target
its application. May I point out that after six years to make the
wording perfect, we now have made it “more perfect.”
The next was 1810.4.1.3 Driving near uncased concrete. This
passed 13 to 1 by the ICC committee, and we revised it to placate
the one who liked the Proposal but not our wording. The change
did improve the section. This modification dealt with disturbance
of uncased foundation elements if sheet piling or other piles were
driven near the uncased concrete.
The last was 1810.4.5 Vibratory driving. The existing section
required a static load test when driving piles with a vibratory
hammer. This section now exempts cases where the pile is only
for lateral loads or for piles started with a vibratory hammer and
finished with an impact hammer. Piles completed with an impact
hammer now are subject to the same load test provisions as any
impact-driven pile.
The building officials in Clark County passed these by margins
in the range of 123 to 2. Then in December, we learned
that we passed the online voting by more than the required
two-thirds margin. So, after six-plus years, we passed 23
changes to the IBC Deep Foundation section. Our work is finished,
and we can now lounge on the beach. Please pass the
suntan lotion.
But not so fast! We are creatures of habit. We are now embarking
on the next round because “Idle hands are the Devil’s tools”
certainly applies to the GeoCoalition! t
Now for the Proposals:
1810.3.6 Splices. Splices shall be constructed so as to provide and maintain true alignment and position of the component parts of the deep
foundation element during installation and subsequent thereto and shall be designed to resist the axial and shear forces and moments occurring at
the location of the splice during driving and for design load combinations. Where deep foundation elements of the same type are being spliced,
splices shall develop not less than 50 percent of the bending strength of the weaker section. Where deep foundation elements of different materials
or different types are being spliced, splices shall develop the full compressive strength and not less than 50 percent of the tension and bending
strength of the weaker section. Where structural steel cores are to be spliced, the ends shall be milled or ground to provide full contact and shall be
full-depth welded.
Exception: Splices conforming to generally accepted engineering practices where approved by the building official for buildings assigned to
Seismic Design Category A or B.
Exception: For buildings assigned to Seismic Design Category A or B. splices need not comply with the 50 percent tension and bending
strength requirements where justified by supporting data.
Splices occurring in the upper 10 feet (3048 mm) of the embedded portion of an element shall be designed to resist at allowable stresses the
moment and shear that would result from an assumed eccentricity of the axial load of 3 inches (76 mm), or the element shall be braced in
accordance with Section 1810.2.2 to other deep foundation elements that do not have splices in the upper 10 feet (3048 mm) of embedment.
1810.4.1.3 Driving near uncased concrete. Deep foundation elements shall not be driven within six element diameters center to center in granular
soils or within one-half the element length in cohesive soils of an uncased element filled with concrete less than 48 hours old unless approved by the
building official. During If driving near uncased concrete elements, causes if the concrete surface in any completed element to rises or drops
significantly or bleeds additional water, the previously completed element shall be replaced. Driven uncased deep foundation elements shall not be
installed in soils that could cause heave.
1810.4.5 Vibratory driving. Vibratory drivers shall only be used to install deep foundation elements where the
element load capacity is verified by load tests in accordance with Section 1810.3.3.1.2. The installation of production
elements shall be controlled according to power consumption, rate of penetration or other approved means that ensure
element capacities equal or exceed those of the test elements.
Exceptions:
1. The pile installation is completed by driving w ith an impact hammer in accordance with Section 1810.3.3.1.1.
2. The pjle is to be used only for lateral resistance.
74 | ISSUE 5 2020 www.piledrivers.org
/www.piledrivers.org
