International Building Code Section 1810


International Building Code 1810.1

General. The materials, reinforcement and installation
of cast-in-place concrete piles shall conform to Sections
1810.1.1 through 1810.1.3.

Materials. Concrete shall have a 28-day specified
compressive strength (f c) of not less than 2,500 psi (17.24
MPa). Where concrete is placed through a funnel hopper at
the top of the pile, the concrete mix shall be designed and
proportioned so as to produce a cohesiveworkable mix having
a slump of not less than 4 inches (102 mm) and not more
than 6 inches (152 mm). Where concrete is to be pumped,
the mix design including slump shall be adjusted to produce
a pumpable concrete.

Reinforcement. Except for steel dowels embedded
5 feet (1524 mm) or less in the pile and as provided in
Section 1810.3.4, reinforcement where required shall be
assembled and tied together and shall be placed in the pile as
a unit before the reinforced portion of the pile is filled with
concrete except in augered uncased cast-in-place piles. Tied
reinforcement in augered uncased cast-in-place piles shall
be placed after piles are concreted, while the concrete is still
in a semifluid state.

Reinforcement in Seismic Design Category
C. Where a structure is assigned to Seismic Design
Category C in accordance with Section 1613, the following
shall apply. A minimum longitudinal reinforcement
ratio of 0.0025 shall be provided for uncased
cast-in-place concrete drilled or augered piles, piers or
caissons in the top one-third of the pile length, a minimum
length of 10 feet (3048 mm) below the ground or
that required by analysis, whichever length is greatest.
The minimum reinforcement ratio, but no less than that
ratio required by rational analysis, shall be continued
throughout the flexural length of the pile. There shall be a
minimum of four longitudinal bars with closed ties (or
equivalent spirals) of a minimum 3/8 inch (9 mm) diameter
provided at 16-longitudinal-bar diameter maximum
spacing. Transverse confinement reinforcement with a
maximum spacing of 6 inches (152 mm) or 8-longitudinal-
bar diameters, whichever is less, shall be provided
within a distance equal to three times the least pile
dimension of the bottom of the pile cap.

Reinforcement in Seismic Design Category
D, E or F. Where a structure is assigned to Seismic
Design Category D, E or F in accordance with Section
1613, the requirements for Seismic Design Category C
given above shall be met, in addition to the following. A
minimum longitudinal reinforcement ratio of 0.005 shall
be provided for uncased cast-in-place drilled or augered
concrete piles, piers or caissons in the top one-half of the
pile length a minimum length of 10 feet (3048 mm)
below ground or throughout the flexural length of the
pile, whichever length is greatest. The flexural length
shall be taken as the length of the pile to a point where the
concrete section cracking moment strength multiplied by
0.4 exceeds the required moment strength at that point.
There shall be a minimum of four longitudinal bars with
transverse confinement reinforcement provided in the
pile in accordance with Sections 21.4.4.1, 21.4.4.2 and
21.4.4.3 of ACI 318 within three times the least pile
dimension of the bottom of the pile cap.Atransverse spiral
reinforcement ratio of not less than one-half of that
required in Section 21.4.4.1( a) ofACI 318 for other than
Class E, F or liquefiable sites is permitted. Tie spacing
throughout the remainder of the concrete section shall
neither exceed 12-longitudinal-bar diameters, one-half
the least dimension of the section, nor 12 inches (305
mm). Ties shall be a minimum of No. 3 bars for piles with
a least dimension up to 20 inches (508 mm), and No. 4
bars for larger piles.

Concrete placement. Concrete shall be placed in
such a manner as to ensure the exclusion of any foreign matter
and to secure a full-sized shaft. Concrete shall not be
placed through water except where a tremie or other
approvedmethod is used.When depositing concrete fromthe
top of the pile, the concrete shall not be chuted directly into
366 2006 INTERNATIONAL BUILDING CODE
SOILS AND FOUNDATIONS
the pile but shall be poured in a rapid and continuous operation
through a funnel hopper centered at the top of the pile.

International Building Code 1810.1.1

Materials. Concrete shall have a 28-day specified
compressive strength (f c) of not less than 2,500 psi (17.24
MPa). Where concrete is placed through a funnel hopper at
the top of the pile, the concrete mix shall be designed and
proportioned so as to produce a cohesiveworkable mix having
a slump of not less than 4 inches (102 mm) and not more
than 6 inches (152 mm). Where concrete is to be pumped,
the mix design including slump shall be adjusted to produce
a pumpable concrete.

International Building Code 1810.1.2

Reinforcement. Except for steel dowels embedded
5 feet (1524 mm) or less in the pile and as provided in
Section 1810.3.4, reinforcement where required shall be
assembled and tied together and shall be placed in the pile as
a unit before the reinforced portion of the pile is filled with
concrete except in augered uncased cast-in-place piles. Tied
reinforcement in augered uncased cast-in-place piles shall
be placed after piles are concreted, while the concrete is still
in a semifluid state.

Reinforcement in Seismic Design Category
C. Where a structure is assigned to Seismic Design
Category C in accordance with Section 1613, the following
shall apply. A minimum longitudinal reinforcement
ratio of 0.0025 shall be provided for uncased
cast-in-place concrete drilled or augered piles, piers or
caissons in the top one-third of the pile length, a minimum
length of 10 feet (3048 mm) below the ground or
that required by analysis, whichever length is greatest.
The minimum reinforcement ratio, but no less than that
ratio required by rational analysis, shall be continued
throughout the flexural length of the pile. There shall be a
minimum of four longitudinal bars with closed ties (or
equivalent spirals) of a minimum 3/8 inch (9 mm) diameter
provided at 16-longitudinal-bar diameter maximum
spacing. Transverse confinement reinforcement with a
maximum spacing of 6 inches (152 mm) or 8-longitudinal-
bar diameters, whichever is less, shall be provided
within a distance equal to three times the least pile
dimension of the bottom of the pile cap.

Reinforcement in Seismic Design Category
D, E or F. Where a structure is assigned to Seismic
Design Category D, E or F in accordance with Section
1613, the requirements for Seismic Design Category C
given above shall be met, in addition to the following. A
minimum longitudinal reinforcement ratio of 0.005 shall
be provided for uncased cast-in-place drilled or augered
concrete piles, piers or caissons in the top one-half of the
pile length a minimum length of 10 feet (3048 mm)
below ground or throughout the flexural length of the
pile, whichever length is greatest. The flexural length
shall be taken as the length of the pile to a point where the
concrete section cracking moment strength multiplied by
0.4 exceeds the required moment strength at that point.
There shall be a minimum of four longitudinal bars with
transverse confinement reinforcement provided in the
pile in accordance with Sections 21.4.4.1, 21.4.4.2 and
21.4.4.3 of ACI 318 within three times the least pile
dimension of the bottom of the pile cap.Atransverse spiral
reinforcement ratio of not less than one-half of that
required in Section 21.4.4.1( a) ofACI 318 for other than
Class E, F or liquefiable sites is permitted. Tie spacing
throughout the remainder of the concrete section shall
neither exceed 12-longitudinal-bar diameters, one-half
the least dimension of the section, nor 12 inches (305
mm). Ties shall be a minimum of No. 3 bars for piles with
a least dimension up to 20 inches (508 mm), and No. 4
bars for larger piles.

International Building Code 1810.1.2.1

Reinforcement in Seismic Design Category
C. Where a structure is assigned to Seismic Design
Category C in accordance with Section 1613, the following
shall apply. A minimum longitudinal reinforcement
ratio of 0.0025 shall be provided for uncased
cast-in-place concrete drilled or augered piles, piers or
caissons in the top one-third of the pile length, a minimum
length of 10 feet (3048 mm) below the ground or
that required by analysis, whichever length is greatest.
The minimum reinforcement ratio, but no less than that
ratio required by rational analysis, shall be continued
throughout the flexural length of the pile. There shall be a
minimum of four longitudinal bars with closed ties (or
equivalent spirals) of a minimum 3/8 inch (9 mm) diameter
provided at 16-longitudinal-bar diameter maximum
spacing. Transverse confinement reinforcement with a
maximum spacing of 6 inches (152 mm) or 8-longitudinal-
bar diameters, whichever is less, shall be provided
within a distance equal to three times the least pile
dimension of the bottom of the pile cap.

International Building Code 1810.1.2.2

Reinforcement in Seismic Design Category
D, E or F. Where a structure is assigned to Seismic
Design Category D, E or F in accordance with Section
1613, the requirements for Seismic Design Category C
given above shall be met, in addition to the following. A
minimum longitudinal reinforcement ratio of 0.005 shall
be provided for uncased cast-in-place drilled or augered
concrete piles, piers or caissons in the top one-half of the
pile length a minimum length of 10 feet (3048 mm)
below ground or throughout the flexural length of the
pile, whichever length is greatest. The flexural length
shall be taken as the length of the pile to a point where the
concrete section cracking moment strength multiplied by
0.4 exceeds the required moment strength at that point.
There shall be a minimum of four longitudinal bars with
transverse confinement reinforcement provided in the
pile in accordance with Sections 21.4.4.1, 21.4.4.2 and
21.4.4.3 of ACI 318 within three times the least pile
dimension of the bottom of the pile cap.Atransverse spiral
reinforcement ratio of not less than one-half of that
required in Section 21.4.4.1( a) ofACI 318 for other than
Class E, F or liquefiable sites is permitted. Tie spacing
throughout the remainder of the concrete section shall
neither exceed 12-longitudinal-bar diameters, one-half
the least dimension of the section, nor 12 inches (305
mm). Ties shall be a minimum of No. 3 bars for piles with
a least dimension up to 20 inches (508 mm), and No. 4
bars for larger piles.

International Building Code 1810.1.3

Concrete placement. Concrete shall be placed in
such a manner as to ensure the exclusion of any foreign matter
and to secure a full-sized shaft. Concrete shall not be
placed through water except where a tremie or other
approvedmethod is used.When depositing concrete fromthe
top of the pile, the concrete shall not be chuted directly into
366 2006 INTERNATIONAL BUILDING CODE
SOILS AND FOUNDATIONS
the pile but shall be poured in a rapid and continuous operation
through a funnel hopper centered at the top of the pile.

International Building Code 1810.2

Enlarged base piles. Enlarged base piles shall conform
to the requirements of Sections 1810.2.1 through 1810.2.5.

Materials. The maximum size for coarse aggregate
for concrete shall be 3/4 inch (19.1 mm). Concrete to be
compacted shall have a zero slump.

Allowable stresses. The maximum allowable
design compressive stress for concrete not placed in a permanent
steel casing shall be 25 percent of the 28-day specified
compressive strength (f c). Where the concrete is place
in a permanent steel casing, the maximum allowable concrete
stress shall be 33 percent of the 28-day specified compressive
strength (f c).

Installation. Enlarged bases formed either by compacting
concrete or driving a precast base shall be formed in
or driven into granular soils. Piles shall be constructed in the
same manner as successful prototype test piles driven for the
project. Pile shafts extending through peat or other organic
soil shall be encased in a permanent steel casing. Where a
cased shaft is used, the shaft shall be adequately reinforced to
resist columnaction or the annular space around the pile shaft
shall be filled sufficiently to reestablish lateral support by the
soil. Where pile heave occurs, the pile shall be replaced
unless it is demonstrated that the pile is undamaged and capable
of carrying twice its design load.

Load-bearing capacity. Pile load-bearing capacity
shall be verified by load tests in accordance with Section
1808.2.8.3.

Concrete cover. The minimum concrete cover
shall be 21/2 inches (64 mm) for uncased shafts and 1 inch
(25 mm) for cased shafts.

International Building Code 1810.2.1

Materials. The maximum size for coarse aggregate
for concrete shall be 3/4 inch (19.1 mm). Concrete to be
compacted shall have a zero slump.

International Building Code 1810.2.2

Allowable stresses. The maximum allowable
design compressive stress for concrete not placed in a permanent
steel casing shall be 25 percent of the 28-day specified
compressive strength (f c). Where the concrete is place
in a permanent steel casing, the maximum allowable concrete
stress shall be 33 percent of the 28-day specified compressive
strength (f c).

International Building Code 1810.2.3

Installation. Enlarged bases formed either by compacting
concrete or driving a precast base shall be formed in
or driven into granular soils. Piles shall be constructed in the
same manner as successful prototype test piles driven for the
project. Pile shafts extending through peat or other organic
soil shall be encased in a permanent steel casing. Where a
cased shaft is used, the shaft shall be adequately reinforced to
resist columnaction or the annular space around the pile shaft
shall be filled sufficiently to reestablish lateral support by the
soil. Where pile heave occurs, the pile shall be replaced
unless it is demonstrated that the pile is undamaged and capable
of carrying twice its design load.

International Building Code 1810.2.4

Load-bearing capacity. Pile load-bearing capacity
shall be verified by load tests in accordance with Section
1808.2.8.3.

International Building Code 1810.2.5

Concrete cover. The minimum concrete cover
shall be 21/2 inches (64 mm) for uncased shafts and 1 inch
(25 mm) for cased shafts.

International Building Code 1810.3

Drilled or augered uncased piles. Drilled or augered
uncased piles shall conform to Sections 1810.3.1 through
1810.3.5.

Allowable stresses. The allowable design stress in
the concrete of drilled or augered uncased piles shall not
exceed 33 percent of the 28-day specified compressive
strength (f ‘c). The allowable compressive stress of reinforcement
shall not exceed 40 percent of the yield strength
of the steel or 25,500 psi (175.8 MPa).

Dimensions. The pile length shall not exceed 30
times the average diameter. The minimum diameter shall be
12 inches (305 mm).
Exception: The length of the pile is permitted to exceed
30 times the diameter, provided that the design and installation
of the pile foundation are under the direct supervision
of a registered design professional knowledgeable in
the field of soil mechanics and pile foundations.The registered
design professional shall certify to the building official
that the piles were installed in compliance with the
approved construction documents.

Installation. Where pile shafts are formed
through unstable soils and concrete is placed in an
open-drilled hole, a steel liner shall be inserted in the hole
prior to placing the concrete. Where the steel liner is withdrawn
during concreting, the level of concrete shall be
maintained above the bottom of the liner at a sufficient
height to offset any hydrostatic or lateral soil pressure.
Where concrete is placed by pumping through a hollow-
stem auger, the auger shall be permitted to rotate in a
clockwise direction during withdrawal. The auger shall be
withdrawn in continuous increments. Concreting pumping
pressures shall be measured and maintained high enough at
all times to offset hydrostatic and lateral earth pressures.
Concrete volumes shall be measured to ensure that the volume
of concrete placed in each pile is equal to or greater
than the theoretical volume of the hole created by the auger.
Where the installation process of any pile is interrupted or a
loss of concreting pressure occurs, the pile shall be redrilled
to 5 feet (1524 mm) below the elevation of the tip of the
auger when the installation was interrupted or concrete
pressurewas lost and reformed. Augered cast-in-place piles
shall not be installed within six pile diameters center to center
of a pile filled with concrete less than 12 hours old, unless
approved by the building official. If the concrete level in any
completed pile drops due to installation of an adjacent pile,
the pile shall be replaced.

Reinforcement. For piles installed with a hollow-
stem auger where full-length longitudinal steel reinforcement
is placed without lateral ties, the reinforcement
shall be placed through the hollowstem of the auger prior to
filling the pile with concrete. All pile reinforcement shall
have a concrete cover of not less than 2.5 inches (64 mm).
Exception: Where physical constraints do not allow the
placement of the longitudinal reinforcement prior to filling
the pile with concrete or where partial-length longitudinal
reinforcement is placed without lateral ties, the
reinforcement is allowed to be placed after the piles are
completely concreted but while concrete is still in a semifluid
state.

Reinforcement in Seismic Design Category C,
D, E or F. Where a structure is assigned to Seismic Design
Category C, D, E or F in accordance with Section 1613, the
corresponding requirements of Sections 1810.1.2.1 and
1810.1.2.2 shall be met.

International Building Code 1810.3.1

Allowable stresses. The allowable design stress in
the concrete of drilled or augered uncased piles shall not
exceed 33 percent of the 28-day specified compressive
strength (f ‘c). The allowable compressive stress of reinforcement
shall not exceed 40 percent of the yield strength
of the steel or 25,500 psi (175.8 MPa).

International Building Code 1810.3.2

Dimensions. The pile length shall not exceed 30
times the average diameter. The minimum diameter shall be
12 inches (305 mm).
Exception: The length of the pile is permitted to exceed
30 times the diameter, provided that the design and installation
of the pile foundation are under the direct supervision
of a registered design professional knowledgeable in
the field of soil mechanics and pile foundations.The registered
design professional shall certify to the building official
that the piles were installed in compliance with the
approved construction documents.

International Building Code 1810.3.3

Installation. Where pile shafts are formed
through unstable soils and concrete is placed in an
open-drilled hole, a steel liner shall be inserted in the hole
prior to placing the concrete. Where the steel liner is withdrawn
during concreting, the level of concrete shall be
maintained above the bottom of the liner at a sufficient
height to offset any hydrostatic or lateral soil pressure.
Where concrete is placed by pumping through a hollow-
stem auger, the auger shall be permitted to rotate in a
clockwise direction during withdrawal. The auger shall be
withdrawn in continuous increments. Concreting pumping
pressures shall be measured and maintained high enough at
all times to offset hydrostatic and lateral earth pressures.
Concrete volumes shall be measured to ensure that the volume
of concrete placed in each pile is equal to or greater
than the theoretical volume of the hole created by the auger.
Where the installation process of any pile is interrupted or a
loss of concreting pressure occurs, the pile shall be redrilled
to 5 feet (1524 mm) below the elevation of the tip of the
auger when the installation was interrupted or concrete
pressurewas lost and reformed. Augered cast-in-place piles
shall not be installed within six pile diameters center to center
of a pile filled with concrete less than 12 hours old, unless
approved by the building official. If the concrete level in any
completed pile drops due to installation of an adjacent pile,
the pile shall be replaced.

International Building Code 1810.3.4

Reinforcement. For piles installed with a hollow-
stem auger where full-length longitudinal steel reinforcement
is placed without lateral ties, the reinforcement
shall be placed through the hollowstem of the auger prior to
filling the pile with concrete. All pile reinforcement shall
have a concrete cover of not less than 2.5 inches (64 mm).
Exception: Where physical constraints do not allow the
placement of the longitudinal reinforcement prior to filling
the pile with concrete or where partial-length longitudinal
reinforcement is placed without lateral ties, the
reinforcement is allowed to be placed after the piles are
completely concreted but while concrete is still in a semifluid
state.

International Building Code 1810.3.5

Reinforcement in Seismic Design Category C,
D, E or F. Where a structure is assigned to Seismic Design
Category C, D, E or F in accordance with Section 1613, the
corresponding requirements of Sections 1810.1.2.1 and
1810.1.2.2 shall be met.

International Building Code 1810.4

Driven uncased piles. Driven uncased piles shall conform
to Sections 1810.4.1 through 1810.4.4.

Allowable stresses. The allowable design stress in
the concrete shall not exceed 25 percent of the 28-day specified
compressive strength (f c) applied to a cross-sectional
area not greater than the inside area of the drive casing or
mandrel.

Dimensions. The pile length shall not exceed 30
times the average diameter. The minimum diameter shall be
12 inches (305 mm).
Exception: The length of the pile is permitted to exceed
30 times the diameter, provided that the design and
installation of the pile foundation is under the direct
supervision of a registered design professional knowledgeable
in the field of soil mechanics and pile foundations.
The registered design professional shall certify to
2006 INTERNATIONAL BUILDING CODE 367
SOILS AND FOUNDATIONS
the building official that the piles were installed in compliance
with the approved design.

Installation. Piles shall not be driven within six
pile diameters center to center in granular soils or within
one-half the pile length in cohesive soils of a pile filled with
concrete less than 48 hours old unless approved by the
building official. If the concrete surface in any completed
pile rises or drops, the pile shall be replaced. Piles shall not
be installed in soils that could cause pile heave.

Concrete cover. Pile reinforcement shall have a
concrete cover of not less than 2.5 inches (64 mm), measured
from the inside face of the drive casing or mandrel.

International Building Code 1810.4.1

Allowable stresses. The allowable design stress in
the concrete shall not exceed 25 percent of the 28-day specified
compressive strength (f c) applied to a cross-sectional
area not greater than the inside area of the drive casing or
mandrel.

International Building Code 1810.4.2

Dimensions. The pile length shall not exceed 30
times the average diameter. The minimum diameter shall be
12 inches (305 mm).
Exception: The length of the pile is permitted to exceed
30 times the diameter, provided that the design and
installation of the pile foundation is under the direct
supervision of a registered design professional knowledgeable
in the field of soil mechanics and pile foundations.
The registered design professional shall certify to
2006 INTERNATIONAL BUILDING CODE 367
SOILS AND FOUNDATIONS
the building official that the piles were installed in compliance
with the approved design.

International Building Code 1810.4.3

Installation. Piles shall not be driven within six
pile diameters center to center in granular soils or within
one-half the pile length in cohesive soils of a pile filled with
concrete less than 48 hours old unless approved by the
building official. If the concrete surface in any completed
pile rises or drops, the pile shall be replaced. Piles shall not
be installed in soils that could cause pile heave.

International Building Code 1810.4.4

Concrete cover. Pile reinforcement shall have a
concrete cover of not less than 2.5 inches (64 mm), measured
from the inside face of the drive casing or mandrel.

International Building Code 1810.5

Steel-cased piles. Steel-cased piles shall comply with
the requirements of Sections 1810.5.1 through 1810.5.4.

Materials. Pile shells or casings shall be of steel
and shall be sufficiently strong to resist collapse and sufficiently
water tight to exclude any foreign materials during
the placing of concrete. Steel shells shall have a sealed tip
with a diameter of not less than 8 inches (203 mm).

Allowable stresses. The allowable design compressive
stress in the concrete shall not exceed 33 percent of
the 28-day specified compressive strength (f c). The allowable
concrete compressive stress shall be 0.40 (f c) for that
portion of the pile meeting the conditions specified in Sections
1810.5.2.1 through 1810.5.2.4.

Shell thickness. The thickness of the steel
shell shall not be less than manufacturer’s standard gage
No. 14 gage (0.068 inch) (1.75 mm) minimum.

Shell type. The shell shall be seamless or provided
with seams of strength equal to the basic material
and be of a configuration that will provide confinement
to the cast-in-place concrete.

Strength. The ratio of steel yield strength (fy)
to 28-day specified compressive strength (f c) shall not
be less than six.

Diameter. The nominal pile diameter shall
not be greater than 16 inches (406 mm).

Installation. Steel shells shall be mandrel driven
their full length in contact with the surrounding soil.
The steel shells shall be driven in such order and with such
spacing as to ensure against distortion of or injury to piles
already in place. A pile shall not be driven within four and
one-half average pile diameters of a pile filled with concrete
less than 24 hours old unless approved by the building official.
Concrete shall not be placed in steel shells within heave
range of driving.

Reinforcement. Reinforcement shall not be
placed within 1 inch (25 mm) of the steel shell. Reinforcing
shall be required for unsupported pile lengths or where the
pile is designed to resist uplift or unbalanced lateral loads.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the reinforcement
requirements for drilled or augered uncased piles in Section
1810.3.5 shall be met.
Exception: A spiral-welded metal casing of a thickness
no less than the manufacturer’s standard gage
No. 14 gage [0.068 inch (1.7 mm)] is permitted to provide
concrete confinement in lieu of the closed ties or
equivalent spirals required in an uncased concrete
pile. Where used as such, the metal casing shall be
protected against possible deleterious action due to
soil constituents, changing water levels or other factors
indicated by boring records of site conditions.

International Building Code 1810.5.1

Materials. Pile shells or casings shall be of steel
and shall be sufficiently strong to resist collapse and sufficiently
water tight to exclude any foreign materials during
the placing of concrete. Steel shells shall have a sealed tip
with a diameter of not less than 8 inches (203 mm).

International Building Code 1810.5.2

Allowable stresses. The allowable design compressive
stress in the concrete shall not exceed 33 percent of
the 28-day specified compressive strength (f c). The allowable
concrete compressive stress shall be 0.40 (f c) for that
portion of the pile meeting the conditions specified in Sections
1810.5.2.1 through 1810.5.2.4.

Shell thickness. The thickness of the steel
shell shall not be less than manufacturer’s standard gage
No. 14 gage (0.068 inch) (1.75 mm) minimum.

Shell type. The shell shall be seamless or provided
with seams of strength equal to the basic material
and be of a configuration that will provide confinement
to the cast-in-place concrete.

Strength. The ratio of steel yield strength (fy)
to 28-day specified compressive strength (f c) shall not
be less than six.

Diameter. The nominal pile diameter shall
not be greater than 16 inches (406 mm).

International Building Code 1810.5.2.1

Shell thickness. The thickness of the steel
shell shall not be less than manufacturer’s standard gage
No. 14 gage (0.068 inch) (1.75 mm) minimum.

International Building Code 1810.5.2.2

Shell type. The shell shall be seamless or provided
with seams of strength equal to the basic material
and be of a configuration that will provide confinement
to the cast-in-place concrete.

International Building Code 1810.5.2.3

Strength. The ratio of steel yield strength (fy)
to 28-day specified compressive strength (f c) shall not
be less than six.

International Building Code 1810.5.2.4

Diameter. The nominal pile diameter shall
not be greater than 16 inches (406 mm).

International Building Code 1810.5.3

Installation. Steel shells shall be mandrel driven
their full length in contact with the surrounding soil.
The steel shells shall be driven in such order and with such
spacing as to ensure against distortion of or injury to piles
already in place. A pile shall not be driven within four and
one-half average pile diameters of a pile filled with concrete
less than 24 hours old unless approved by the building official.
Concrete shall not be placed in steel shells within heave
range of driving.

International Building Code 1810.5.4

Reinforcement. Reinforcement shall not be
placed within 1 inch (25 mm) of the steel shell. Reinforcing
shall be required for unsupported pile lengths or where the
pile is designed to resist uplift or unbalanced lateral loads.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the reinforcement
requirements for drilled or augered uncased piles in Section
1810.3.5 shall be met.
Exception: A spiral-welded metal casing of a thickness
no less than the manufacturer’s standard gage
No. 14 gage [0.068 inch (1.7 mm)] is permitted to provide
concrete confinement in lieu of the closed ties or
equivalent spirals required in an uncased concrete
pile. Where used as such, the metal casing shall be
protected against possible deleterious action due to
soil constituents, changing water levels or other factors
indicated by boring records of site conditions.

International Building Code 1810.5.4.1

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the reinforcement
requirements for drilled or augered uncased piles in Section
1810.3.5 shall be met.
Exception: A spiral-welded metal casing of a thickness
no less than the manufacturer’s standard gage
No. 14 gage [0.068 inch (1.7 mm)] is permitted to provide
concrete confinement in lieu of the closed ties or
equivalent spirals required in an uncased concrete
pile. Where used as such, the metal casing shall be
protected against possible deleterious action due to
soil constituents, changing water levels or other factors
indicated by boring records of site conditions.

International Building Code 1810.6

Concrete-filled steel pipe and tube piles. Concrete-
filled steel pipe and tube piles shall conform to the
requirements of Sections 1810.6.1 through 1810.6.5.

Materials. Steel pipe and tube sections used for
piles shall conform to ASTM A 252 or ASTM A 283. Concrete
shall conform to Section 1810.1.1. The maximum
coarse aggregate size shall be 3/4 inch (19.1 mm).

Allowable stresses. The allowable design compressive
stress in the concrete shall not exceed 33 percent of
the 28-day specified compressive strength (f c). The allowable
design compressive stress in the steel shall not exceed
35 percent of the minimum specified yield strength of the
steel (Fy), provided Fy shall not be assumed greater than
36,000 psi (248 MPa) for computational purposes.
Exception: Where justified in accordance with Section
1808.2.10, the allowable stresses are permitted to be
increased to 0.50 Fy.

Minimum dimensions. Piles shall have a nominal
outside diameter of not less than 8 inches (203 mm) and a
minimum wall thickness in accordance with Section
1809.3.4. For mandrel-driven pipe piles, the minimum wall
thickness shall be 1/10 inch (2.5 mm).

Reinforcement. Reinforcement steel shall conform
to Section 1810.1.2. Reinforcement shall not be placed
within 1 inch (25 mm) of the steel casing.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the following shall apply.
Minimum reinforcement no less than 0.01 times the
cross-sectional area of the pile concrete shall be provided
in the top of the pile with a length equal to two times the
required cap embedment anchorage into the pile cap, but
not less than the tension development length of the reinforcement.
The wall thickness of the steel pipe shall not
be less than 3/16 inch (5 mm).

Placing concrete. The placement of concrete shall
conform to Section 1810.1.3, but is permitted to be chuted
directly into smooth-sided pipes and tubes without a centering
funnel hopper.

International Building Code 1810.6.1

Materials. Steel pipe and tube sections used for
piles shall conform to ASTM A 252 or ASTM A 283. Concrete
shall conform to Section 1810.1.1. The maximum
coarse aggregate size shall be 3/4 inch (19.1 mm).

International Building Code 1810.6.2

Allowable stresses. The allowable design compressive
stress in the concrete shall not exceed 33 percent of
the 28-day specified compressive strength (f c). The allowable
design compressive stress in the steel shall not exceed
35 percent of the minimum specified yield strength of the
steel (Fy), provided Fy shall not be assumed greater than
36,000 psi (248 MPa) for computational purposes.
Exception: Where justified in accordance with Section
1808.2.10, the allowable stresses are permitted to be
increased to 0.50 Fy.

International Building Code 1810.6.3

Minimum dimensions. Piles shall have a nominal
outside diameter of not less than 8 inches (203 mm) and a
minimum wall thickness in accordance with Section
1809.3.4. For mandrel-driven pipe piles, the minimum wall
thickness shall be 1/10 inch (2.5 mm).

International Building Code 1810.6.4

Reinforcement. Reinforcement steel shall conform
to Section 1810.1.2. Reinforcement shall not be placed
within 1 inch (25 mm) of the steel casing.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the following shall apply.
Minimum reinforcement no less than 0.01 times the
cross-sectional area of the pile concrete shall be provided
in the top of the pile with a length equal to two times the
required cap embedment anchorage into the pile cap, but
not less than the tension development length of the reinforcement.
The wall thickness of the steel pipe shall not
be less than 3/16 inch (5 mm).

International Building Code 1810.6.4.1

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, D, E or F in
accordance with Section 1613, the following shall apply.
Minimum reinforcement no less than 0.01 times the
cross-sectional area of the pile concrete shall be provided
in the top of the pile with a length equal to two times the
required cap embedment anchorage into the pile cap, but
not less than the tension development length of the reinforcement.
The wall thickness of the steel pipe shall not
be less than 3/16 inch (5 mm).

International Building Code 1810.6.5

Placing concrete. The placement of concrete shall
conform to Section 1810.1.3, but is permitted to be chuted
directly into smooth-sided pipes and tubes without a centering
funnel hopper.

International Building Code 1810.7

Caisson piles. Caisson piles shall conform to the
requirements of Sections 1810.7.1 through 1810.7.6.

Construction. Caisson piles shall consist of a
shaft section of concrete-filled pipe extending to bedrock
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SOILS AND FOUNDATIONS
with an uncased socket drilled into the bedrock and filled
with concrete. The caisson pile shall have a full-length
structural steel core or a stub core installed in the rock socket
and extending into the pipe portion a distance equal to the
socket depth.

Materials. Pipe and steel cores shall conform to
the material requirements in Section 1809.3. Pipes shall
have a minimum wall thickness of 3/8 inch (9.5 mm) and
shall be fitted with a suitable steel-driving shoe welded to
the bottom of the pipe. Concrete shall have a 28-day specified
compressive strength (f c) of not less than 4,000 psi
(27.58 MPa). The concrete mix shall be designed and proportioned
so as to produce a cohesive workable mix with a
slump of 4 inches to 6 inches (102 mm to 152 mm).

Design. The depth of the rock socket shall be sufficient
to develop the full load-bearing capacity of the caisson
pile with a minimum safety factor of two, but the depth shall
not be less than the outside diameter of the pipe. The design
of the rock socket is permitted to be predicated on the sum of
the allowable load-bearing pressure on the bottom of the
socket plus bond along the sides of the socket. The minimum
outside diameter of the caisson pile shall be 18 inches
(457 mm), and the diameter of the rock socket shall be
approximately equal to the inside diameter of the pile.

Structural core. The gross cross-sectional area of
the structural steel core shall not exceed 25 percent of the
gross area of the caisson. The minimum clearance between
the structural core and the pipe shall be 2 inches (51 mm).
Where cores are to be spliced, the ends shall be milled or
ground to provide full contact and shall be full-depth
welded.

Allowable stresses. The allowable design compressive
stresses shall not exceed the following: concrete,
0.33 f c; steel pipe, 0.35 Fy and structural steel core, 0.50 Fy.

Installation. The rock socket and pile shall be
thoroughly cleaned of foreign materials before filling with
concrete. Steel cores shall be bedded in cement grout at the
base of the rock socket. Concrete shall not be placed through
water except where a tremie or other approved method is
used.

International Building Code 1810.7.1

Construction. Caisson piles shall consist of a
shaft section of concrete-filled pipe extending to bedrock
368 2006 INTERNATIONAL BUILDING CODE
SOILS AND FOUNDATIONS
with an uncased socket drilled into the bedrock and filled
with concrete. The caisson pile shall have a full-length
structural steel core or a stub core installed in the rock socket
and extending into the pipe portion a distance equal to the
socket depth.

International Building Code 1810.7.2

Materials. Pipe and steel cores shall conform to
the material requirements in Section 1809.3. Pipes shall
have a minimum wall thickness of 3/8 inch (9.5 mm) and
shall be fitted with a suitable steel-driving shoe welded to
the bottom of the pipe. Concrete shall have a 28-day specified
compressive strength (f c) of not less than 4,000 psi
(27.58 MPa). The concrete mix shall be designed and proportioned
so as to produce a cohesive workable mix with a
slump of 4 inches to 6 inches (102 mm to 152 mm).

International Building Code 1810.7.3

Design. The depth of the rock socket shall be sufficient
to develop the full load-bearing capacity of the caisson
pile with a minimum safety factor of two, but the depth shall
not be less than the outside diameter of the pipe. The design
of the rock socket is permitted to be predicated on the sum of
the allowable load-bearing pressure on the bottom of the
socket plus bond along the sides of the socket. The minimum
outside diameter of the caisson pile shall be 18 inches
(457 mm), and the diameter of the rock socket shall be
approximately equal to the inside diameter of the pile.

International Building Code 1810.7.4

Structural core. The gross cross-sectional area of
the structural steel core shall not exceed 25 percent of the
gross area of the caisson. The minimum clearance between
the structural core and the pipe shall be 2 inches (51 mm).
Where cores are to be spliced, the ends shall be milled or
ground to provide full contact and shall be full-depth
welded.

International Building Code 1810.7.5

Allowable stresses. The allowable design compressive
stresses shall not exceed the following: concrete,
0.33 f c; steel pipe, 0.35 Fy and structural steel core, 0.50 Fy.

International Building Code 1810.7.6

Installation. The rock socket and pile shall be
thoroughly cleaned of foreign materials before filling with
concrete. Steel cores shall be bedded in cement grout at the
base of the rock socket. Concrete shall not be placed through
water except where a tremie or other approved method is
used.

International Building Code 1810.8

Micropiles. Micropiles shall conform to the requirements
of Sections 1810.8.1 through 1810.8.5.

Construction. Micropiles shall consist of a
grouted section reinforced with steel pipe or steel reinforcing.
Micropiles shall develop their load-carrying capacity
through a bond zone in soil, bedrock or a combination of
soil and bedrock. The full length of the micropile shall contain
either a steel pipe or steel reinforcement.

Materials. Grout shall have a 28-day specified
compressive strength (f ‘c) of not less than 4,000 psi (27.58
MPa). The grout mix shall be designed and proportioned so
as to produce a pumpable mixture. Reinforcement steel
shall be deformed bars in accordance with ASTM A 615
Grade 60 or 75 or ASTM A 722 Grade 150.
Pipe/casing shall have a minimum wall thickness of 3/16
inch (4.8 mm) and as required to meet Section 1808.2.7.
Pipe/casing shall meet the tensile requirements of ASTM A
252 Grade 3, except the minimum yield strength shall be as
used in the design submittal [typically 50,000 psi to 80,000
psi (345 MPa to 552 MPa)] and minimum elongation shall
be 15 percent.

Allowable stresses. The allowable design compressive
stress on grout shall not exceed 0.33 f c. The allowable
design compressive stress on steel pipe and steel
reinforcement shall not exceed the lesser of 0.4 Fy, or 32,000
psi (220 MPa). The allowable design tensile stress for steel
reinforcement shall not exceed 0.60 Fy. The allowable
design tensile stress for the cement grout shall be zero.

Reinforcement. For piles or portions of piles
grouted inside a temporary or permanent casing or inside a
hole drilled into bedrock or a hole drilled with grout, the
steel pipe or steel reinforcement shall be designed to carry at
least 40 percent of the design compression load. Piles or
portions of piles grouted in an open hole in soil without temporary
or permanent casing and without suitable means of
verifying the hole diameter during grouting shall be
designed to carry the entire compression load in the reinforcing
steel. Where a steel pipe is used for reinforcement,
the portion of the cement grout enclosed within the pipe is
permitted to be included at the allowable stress of the grout.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, a permanent
steel casing shall be provided from the top of the pile
down 120 percent times the flexural length. The flexural
length shall be determined in accordance with Section
1808.1. Where a structure is assigned to Seismic Design
Category D, E or F, the pile shall be considered as an
alternative system. In accordance with Section 104.11,
the alternative pile system design, supporting documentation
and test data shall be submitted to the building official
for review and approval.

Installation. The pile shall be permitted to be
formed in a hole advanced by rotary or percussive drilling
methods, with or without casing. The pile shall be grouted
with a fluid cement grout. The grout shall be pumped
through a tremie pipe extending to the bottom of the pile
until grout of suitable quality returns at the top of the pile.
The following requirements apply to specific installation
methods:
1. For piles grouted inside a temporary casing, the reinforcing
steel shall be inserted prior to withdrawal of
the casing. The casing shall be withdrawn in a controlled
manner with the grout level maintained at the
top of the pile to ensure that the grout completely fills
the drill hole. During withdrawal of the casing, the
grout level inside the casing shall be monitored to
check that the flow of grout inside the casing is not
obstructed.
2. For a pile or portion of a pile grouted in an open drill
hole in soil without temporary casing, the minimum
design diameter of the drill hole shall be verified by a
suitable device during grouting.
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SOILS AND FOUNDATIONS
3. For piles designed for end bearing, a suitable means
shall be employed to verify that the bearing surface is
properly cleaned prior to grouting.
4. Subsequent piles shall not be drilled near piles that
have been grouted until the grout has had sufficient
time to harden.
5. Piles shall be grouted as soon as possible after drilling
is completed.
6. For piles designed with casing full length, the casing
must be pulled back to the top of the bond zone and
reinserted or some other suitable means shall be
employed to verify grout coverage outside the casing.

International Building Code 1810.8.1

Construction. Micropiles shall consist of a
grouted section reinforced with steel pipe or steel reinforcing.
Micropiles shall develop their load-carrying capacity
through a bond zone in soil, bedrock or a combination of
soil and bedrock. The full length of the micropile shall contain
either a steel pipe or steel reinforcement.

International Building Code 1810.8.2

Materials. Grout shall have a 28-day specified
compressive strength (f ‘c) of not less than 4,000 psi (27.58
MPa). The grout mix shall be designed and proportioned so
as to produce a pumpable mixture. Reinforcement steel
shall be deformed bars in accordance with ASTM A 615
Grade 60 or 75 or ASTM A 722 Grade 150.
Pipe/casing shall have a minimum wall thickness of 3/16
inch (4.8 mm) and as required to meet Section 1808.2.7.
Pipe/casing shall meet the tensile requirements of ASTM A
252 Grade 3, except the minimum yield strength shall be as
used in the design submittal [typically 50,000 psi to 80,000
psi (345 MPa to 552 MPa)] and minimum elongation shall
be 15 percent.

International Building Code 1810.8.3

Allowable stresses. The allowable design compressive
stress on grout shall not exceed 0.33 f c. The allowable
design compressive stress on steel pipe and steel
reinforcement shall not exceed the lesser of 0.4 Fy, or 32,000
psi (220 MPa). The allowable design tensile stress for steel
reinforcement shall not exceed 0.60 Fy. The allowable
design tensile stress for the cement grout shall be zero.

International Building Code 1810.8.4

Reinforcement. For piles or portions of piles
grouted inside a temporary or permanent casing or inside a
hole drilled into bedrock or a hole drilled with grout, the
steel pipe or steel reinforcement shall be designed to carry at
least 40 percent of the design compression load. Piles or
portions of piles grouted in an open hole in soil without temporary
or permanent casing and without suitable means of
verifying the hole diameter during grouting shall be
designed to carry the entire compression load in the reinforcing
steel. Where a steel pipe is used for reinforcement,
the portion of the cement grout enclosed within the pipe is
permitted to be included at the allowable stress of the grout.

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, a permanent
steel casing shall be provided from the top of the pile
down 120 percent times the flexural length. The flexural
length shall be determined in accordance with Section
1808.1. Where a structure is assigned to Seismic Design
Category D, E or F, the pile shall be considered as an
alternative system. In accordance with Section 104.11,
the alternative pile system design, supporting documentation
and test data shall be submitted to the building official
for review and approval.

International Building Code 1810.8.4.1

Seismic reinforcement. Where a structure is
assigned to Seismic Design Category C, a permanent
steel casing shall be provided from the top of the pile
down 120 percent times the flexural length. The flexural
length shall be determined in accordance with Section
1808.1. Where a structure is assigned to Seismic Design
Category D, E or F, the pile shall be considered as an
alternative system. In accordance with Section 104.11,
the alternative pile system design, supporting documentation
and test data shall be submitted to the building official
for review and approval.

International Building Code 1810.8.5

Installation. The pile shall be permitted to be
formed in a hole advanced by rotary or percussive drilling
methods, with or without casing. The pile shall be grouted
with a fluid cement grout. The grout shall be pumped
through a tremie pipe extending to the bottom of the pile
until grout of suitable quality returns at the top of the pile.
The following requirements apply to specific installation
methods:
1. For piles grouted inside a temporary casing, the reinforcing
steel shall be inserted prior to withdrawal of
the casing. The casing shall be withdrawn in a controlled
manner with the grout level maintained at the
top of the pile to ensure that the grout completely fills
the drill hole. During withdrawal of the casing, the
grout level inside the casing shall be monitored to
check that the flow of grout inside the casing is not
obstructed.
2. For a pile or portion of a pile grouted in an open drill
hole in soil without temporary casing, the minimum
design diameter of the drill hole shall be verified by a
suitable device during grouting.
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SOILS AND FOUNDATIONS
3. For piles designed for end bearing, a suitable means
shall be employed to verify that the bearing surface is
properly cleaned prior to grouting.
4. Subsequent piles shall not be drilled near piles that
have been grouted until the grout has had sufficient
time to harden.
5. Piles shall be grouted as soon as possible after drilling
is completed.
6. For piles designed with casing full length, the casing
must be pulled back to the top of the bond zone and
reinserted or some other suitable means shall be
employed to verify grout coverage outside the casing.