Deletion legend:
[1- Default Not related
to structural wind resistance design]
[2- Fire/Life Safety]
[3- Covered in model base
code]
Section 1817 through Section 1834 Florida Specific for the HVHZ
SECTION 1817
HIGH-VELOCITY HURRICANE ZONES
EXCAVATIONS
1817.1 General. Until provisions for permanent support
have been made, all excavations shall be properly guarded and protected so as
to prevent them from becoming dangerous to life and property and shall be sheet
piled, braced and/or shored, where necessary, to prevent the adjoining earth
from caving in; such protection to be provided by the person causing the
excavation to be made. All excavations shall comply with the minimum
requirements of Section 553.60, Florida Statute "Trench Safety Act,"
and 29 CFR 1926-650 (P) "Occupational Safety and Health Administration
Excavation Safety Act." No excavation, for any purpose, shall extend
within 1 foot (305 mm) of the angle of repose of any soil bearing footing or
foundation unless such footing or foundation is first properly underpinned or
protected against settlement.
1817.2 Permanent excavations. No permanent excavation
shall be made nor shall any construction excavations be left on any lot that
will endanger adjoining property or buildings or be a menace to public health
or safety. Any such excavations made or maintained shall be properly drained
and such drainage provisions shall function properly as long as the excavation
exists. Permanent excavations shall have retaining walls of steel, masonry,
concrete or similar approved material of sufficient strength to retain the
embankment together with any surcharged loads.
1817.3 Enforcement. Where, in the opinion of the building
official, an unsafe condition may result or damage may occur as the result of
an excavation, he or she may order the work stopped or may approve the work of
excavation subject to such limitations, as he or she may deem necessary.
[1- Default Not related to structural wind resistance design]
SECTION 1818
HIGH-VELOCITY HURRICANE ZONES
BEARING CAPACITY OF SOIL
1818.1 Design bearing capacity. Plans for new buildings,
structures or additions shall clearly identify the nature of the soil under the
structure and the allowable bearing capacity used in sizing the building foundation
support system.
Exception: See Section 1822.1 for plans for new
buildings, structures or additions that are to be supported on a piling
foundation system.
1818.2 Allowable bearing capacity. Prior to the
installation of any footing foundation system for new buildings, structures or
additions, the building official shall be provided with a statement of
allowable bearing capacity from an architect or professional engineer. Said
statement shall clearly identify the allowable in-place bearing capacity of the
building pad for the new building or addition and verify the existing soil
conditions. The certified in-place bearing capacity shall have been determined
using recognized tests or rational analysis and shall meet or exceed the design
bearing capacity identified under Section 1818.1.
[1- Default Not related to structural wind resistance design]
SECTION 1819
HIGH-VELOCITY HURRICANE ZONES
SOIL BEARING FOUNDATIONS
1819.1 General. Footings shall be constructed of
reinforced concrete, as set forth in Chapter 19 (High-Velocity Hurricane Zones)
of this code and in this section, and shall, insofar as is practicable, be so
designed that the soil pressure shall be reasonably uniform to minimize
differential settlement.
1819.2 Continuous wall footings.
1819.2.1 Footings under walls shall be continuous or
continuity otherwise provided and shall be not less than required to keep the
soil pressure within that set forth in Section 1818 nor less than the following
minimums:
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1819.2.2 Masonry fences, flower bins, steps and similar
decorative structures shall have reinforced concrete foundations designed for
all live, dead and wind loads as set forth in Chapter 16 (High-Velocity
Hurricane Zones) of this code. The minimum size of these foundations shall be
as follows:
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1819.2.3 Based on rational analysis and soil
investigation as set forth in Section 1818, the footing size or bearing
capacity may vary, but the minimum width of a footing under masonry fences,
flower bins, steps and similar decorative structures shall not be less than 16
inches (406 mm) nor less than 8 inches (203 mm) more than the width of the
wall.
Exception: Masonry fences, wing walls and other similar
walls that are exposed to lateral wind forces and do not have any lateral
restraint above grade, shall have their continuous wall footings placed so the
top of footing is no less than 16 inches (406 mm) below grade.
1819.3 The minimum continuous footings specified in this
section shall be reinforced as follows:
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1819.3.1 Where footings are 30 inches (762 mm) or more in
width, cross bars designed to resist bending at the face of the foundation wall
shall be provided.
1819.3.1.1 Equivalent areas in #4 reinforcing bars may be
substituted for the sizes as specified in Section 1819.3.
1819.3.1.2 Splices in reinforcing bars shall be not less
than 36 bar diameters and reinforcement shall be continuous around all corners
and changes in direction. Continuity shall be provided at corners or changes in
direction by bending the longitudinal steel around the corner 48 bar diameters
or by adding matching reinforcing steel, which shall extend 48 bar diameters
from each corner or change in direction When three or more bars are required,
the bars shall be held in place and aligned by transverse bars spaced not more
than 4 feet (1219 mm) apart.
1819.3.1.3 The reinforcement for footings and other
principal structural members in which concrete is deposited against the ground
shall have not less than 3 inches (76 mm) of concrete between the reinforcement
and the ground contact surface. If concrete surfaces after removal of the forms
are to be exposed to the weather or be in contact with the ground, the
reinforcement shall be protected with not less than 2 inches (51 mm) of concrete
for bars larger than #5 and 11/2 (38 mm) for #5 or smaller bars.
1819.3.1.4 Excavations for continuous footings shall be
cut true to line and grade and the sides of footings shall be formed, except
where soil conditions are such that the sides of the excavation stand firm and
square. Excavations shall be made to firm, clean bearing soil.
1819.4 Continuous footings shall be placed level and any
changes in the grade of such footings shall be made with a vertical tie of the
same cross section and design as the footings, or the smaller of the footings,
so joined.
1819.4.1 Continuous footings with eccentric loading shall
be designed to limit the soil pressure at the edges to within acceptable values
by means of counterbalancing or by other approved methods.
1819.4.2 When foundation walls are to be poured
separately from the footing, they shall be keyed and doweled to the footing
with no less than #4 dowels, 20 diameters in length above and below the joint,
spaced not more than 4 feet (1219 mm) apart. Where footing depth does not allow
straight dowels, standard hooks will be allowable.
1819.4.3 Concrete footing and pads shall not receive
superimposed loads until 12 hours or more after the concrete is placed.
1819.4.4 Excavations for footings and foundations, which
are to serve as forms, shall be thoroughly wetted prior to the placement of
concrete.
1819.4.5 The top of all continuous footings shall be a
minimum of 8 inches (203 mm) below grade.
1819.5 Isolated footings. Dimensions for an isolated
footing shall not be less than 12 inches (305 mm) deep and 24 inches square
(.02 m2). Isolated footings in soil having low lateral restraint and isolated
piers shall be provided with adequate bracing to resist lateral movement.
1819.5.1 Isolated footings with eccentric loading shall
be designed to limit the soil pressure at the edges by means of footing straps
or other approved methods.
1819.5.2 When isolated footings support reinforced
concrete columns, dowels equivalent in number and area to the column
reinforcement and having a length not less than 36 diameters above and below
the joint shall be provided in the footing. Where the footing depth precludes
straight dowels, standard ACI hooks will be allowable. Such dowels, or anchor
bolts as required for steel columns, shall be held to proper grade and location
during the pouring of the footing by means of templates or by other approved
methods.
1819.5.3 The top of all isolated footings shall be a
minimum of 8 inches (203 mm) below grade.
1819.5.4 Any isolated footing subjected to uplift and/or
overturning forces shall be specifically designed for that purpose, as set
forth in Section 1620.
1819.6 Lateral sliding resistance. The resistance of
structural walls to lateral sliding shall be calculated by combining the values
derived from the lateral bearing and the lateral sliding resistance shown in
Table 1819.6 unless data to substantiate the use of higher values are submitted
for approval. For clay, sandy clay and clayey silt, in no case shall the lateral
sliding resistance exceed one-half the dead load.
TABLE 1819.6 ALLOWABLE LATERAL PRESSURE
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1819.6.1 Increases in allowable lateral sliding
resistance. The resistance values derived from the table may be increased by
the tabular value for each additional foot of depth to a maximum of 15 times
the tabular value. Isolated poles for uses such as flagpoles or signs and poles
used to support buildings which are not adversely affected by 1/2-inch (12.7
mm) motion at the ground surface because of short-term lateral loads may be
designed using lateral bearing values equal to two times the tabular values.
1819.7 Designs employing lateral bearing. Designs to
resist lateral loads employing posts or poles as columns embedded in earth or
embedded in concrete footings in the earth shall conform to the requirements of
Sections 1819.7.1 through 1819.7.2.1.
1819.7.1 Limitation. Posts embedded in earth shall not be
used to provide lateral support for structural or non structural materials such
as plaster, masonry or concrete unless bracing is provided that develops the
limited deflection required.
1819.7.2 Design criteria. The depth to resist lateral loads
shall be determined by the design criteria in Sections 1819.7.2.1 through
1819.7.2.2 or by other methods approved by the building official.
1819.7.2.1 Unconstrained. The following formula shall be
used in determining the depth of embedment required to resist the lateral loads
where no constraint is provided at the ground surface, such as a structural
diaphragm.
d = 0.5A {1 + [1 + (4.36h / A )]1/2}
Where:
A = 2.34P /(S 1b )
b = diameter of round post or diagonal
dimension of square post or footing, feet.
d = depth of embedment in earth in feet
but not over 12 feet (3658 mm) for purpose of computing lateral pressure.
h = distance in feet from ground surface
to point of application of P .
P = applied lateral force, pounds.
S 1 = Allowable lateral soil-bearing
pressure as set forth in Table 1819.6 based on a depth of one-third the depth
of embedment, pounds per square foot.
S 3 = Allowable
lateral soil-bearing pressure as set forth in Table 1819.6 based on a depth
equal to the depth of embedment, pounds per square foot.
1819.7.2.2 Constrained. The following formula shall be
used in determining the depth of embedment required to resist the lateral loads
where constraint is provided at the ground surface, such as a rigid floor or
rigid ground surface pavement.
d 2 = 4.25(Ph / S 3b )
or alternately
d 2 = 4.25(Mg / S 3b )
Where:
Mg = Moment in the post at grade,
foot-pounds.
[1- Default Not related
to structural wind resistance design]
SECTION 1820
HIGH-VELOCITY HURRICANE ZONES-CONCRETE SLABS ON FILL
1820.1 Concrete floors placed directly on the supporting
soil shall comply with this section.
1820.2 Where it is proposed to place concrete slabs
directly on the supporting soil, a subgrade shall be thoroughly compacted by
approved methods. All fill placed under slabs shall be clean sand or rock, free
of debris and other deleterious materials. The maximum size of rock within 12
inches (305 mm) below the floor slab in compacted fill shall be 3 inches (76
mm) in diameter. Where fill material includes rock, large rocks shall not be
allowed to nest and all voids shall be carefully filled with small stones or
sand, and properly compacted.
1820.3. Concrete floor slabs placed directly on the
supporting soil shall be a minimum of 4 inches (102 mm) in thickness,
reinforced with not less than 0.028 square inches (18 mm2) of reinforcing per
linear foot of slab in each direction.
1820.3.1 Fill supporting such slabs shall be compacted
under the supervision of a special inspector to a minimum of 95 percent of
maximum dry density for all layers, as verified by field density tests
specified in Section1820.3.2.
1820.3.2 Tests shall be made in accordance with Methods
of Test for Moisture Density Relations of Soils, ASTM D 1557 modified to use 25
blows on five layers with a 10-pound (5 kg) hammer dropping 18 inches (457 mm).
In addition, a minimum of one in-place field density test shall be performed
for each 2,500 square feet (232 m2), or fraction thereof, for each lift of
compacted soil, and such testing shall be performed in accordance with either
ASTM D 1556, Standard Test Method for Density of Soil In-Place by the Sandcone;
or ASTM D 2922, Standard Test Methods for Density of Soil and Soil Aggregate
in-place by Nuclear Methods (Shallow Depth), or other approved methods.
1820.3.3 Where a concrete slab is supported by a
foundation wall or continuous footing, the effect of the support shall be
considered in the design.
1820.3.4 All concrete slab edges and concrete beams
supporting exterior walls shall be recessed a minimum of 3/4 inch (19 mm) below
top of slab for a width of the exterior wall, or provided with an alternate
water-stop method approved by the building official.
1820.3.5 The discontinuous edges of all slabs surrounding
swimming pools and floor slabs for screen patios and utility sheds shall be at
least a minimum of 8 inches (203 mm) deep and 8 inches (203 mm) wide and shall
be reinforced with one continuous #5 bar.
1820.3.6 Reinforced concrete slabs on fill for garbage
containers shall be a minimum of 1 foot (305 mm) larger on all sides than the
garbage receptacle (dumpster) and a minimum thickness of 6 inches (152 mm).
1820.4 When polyethylene sheets are used as a vapor
barrier beneath a ground floor slab, the subgrade for that slab shall be
considered a formed surface for the purpose of reinforcing steel coverage.
1820.5 Concrete slabs outside of buildings, other than
patios and pool slabs, where placed directly on the supporting soil, for minor
accessory uses such as, but not limited to, walkways, driveways, minor
equipment pads, etc, shall be not less than 4 inches (102 mm) thick. Such slabs
shall be placed on clean, thoroughly compacted sand or crushed rock free from
organics, debris or other deleterious materials.
[1- Default Not related to structural wind resistance design]
SECTION 1821
HIGH-VELOCITY HURRICANE ZONES-
MONOLITHIC FOOTINGS
1821.1 Monolithic footings under walls shall be
continuous or continuity otherwise provided and shall be not less than required
to keep the soil pressure within that set forth in Section 1818 nor less than
the following minimums:
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Based on rational analysis and soil investigation as set
forth in Section 1818, the footing size or bearing capacity may vary, but the
minimum width of a footing under the main walls of the buildings shall not be
less than 16 inches nor less than 8 inches more than the width of the
foundation wall.
NOTES:
(1) For single story wood frame exterior walls, the
minimum size continuous footing shall be 16 inches deep x 24 inches wide.
(2) Any continuous wall footing acting as a shear wall
foundation shall be specifically designed for that purpose.
1821.1.1 A minimum outside finish grade of 8 inches (203
mm) above the bottom of the exterior monolithic footing shall be required, but
in no case shall the outside finish grade be above the top of the finish slab
surface unless sufficient means to minimize moisture intrusion into the
structure have been provided to the satisfaction of the building official.
1821.1.2 Continuous monolithic footings shall be placed
level and any change in the grade of such footings shall be made with a step of
the same cross section and design as the monolithic footings, or the smaller of
the monolithic footings, so joined.
1821.1.3 Continuous monolithic footings with eccentric
loading shall be designed to limit the soil pressure at the edges to within
acceptable values by means of counterbalancing or by other approved methods.
1821.1.4 Concrete monolithic footings and pads shall not
receive superimposed loads until 12 hours or more after the concrete is placed.
1821.1.5 Excavations for monolithic footings and
foundations, which are to serve as forms, shall be thoroughly wet prior to
placing concrete.
1821.1.6 Monolithic foundation systems shall be limited
for the support of a maximum of two stories and/or floors or a maximum mean
roof height of 25 feet (7620 mm) above grade unless the monolithic foundation
system has been designed by a professional engineer and ample consideration has
been given to the eccentric loading, foundation rotation and shear cracking at
the slab/foundation interface.
1821.1.7 The minimum continuous monolithic footings
specified in this section shall be reinforced as follows:
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1821.1.8 Where footings are 30 inches (762 mm) or more in
width, cross bars designed to resist bending at the face of the foundation wall
shall be provided.
1821.1.9 Equivalent areas in #4 reinforcing bars may be
substituted for the sizes as specified in Section 1821.1.7.
1821.1.10 Splices in reinforcing bars shall be not less
than 36 bar diameters and reinforcement shall be continuous around all corners
and changes in direction. Continuity shall be provided at corners or changes in
direction by bending the longitudinal steel around the corner 48 bar diameters
or by adding matching reinforcing steel, which shall extend 48 bar diameters
from each corner or change in direction. When three or more bars are required,
the bars shall be held in place and alignment by transverse bars spaced not
more than 4 feet (1219 mm) apart.
1821.1.11 The reinforcement for monolithic footings and
other principal structural members in which concrete is deposited against the
ground shall have not less than 3 inches (76 mm) of concrete between the
reinforcement and the ground contact surface. If concrete surfaces after
removal of the forms are to be exposed to the weather or be in contact with the
ground, the reinforcement shall be protected with not less than 2 inches (51
mm) of concrete for bars larger than #5 and 11/2 inches (38 mm) for #5 or
smaller bars.
1821.1.12 Excavations for continuous monolithic footings
shall be cut true to line and grade and the sides of footings shall be formed,
except where soil conditions are such that the sides of the excavation stand
firm and square. Excavations shall be made to firm, clean bearing soil.
1821.1.13 Unless otherwise determined by rational
analysis, monolithic footings shall have transfer reinforcement along the
perimeter of the foundation. Said reinforcement shall be no less than #4
reinforcing steel bars spaced no greater than 12 inches (305 mm) on center and
shall be no less than 5 feet (1524 mm) in length plus a standard ACI hook and
shall be placed to transfer into the slab section commencing at a point no less
than 3 inches (76 mm) from the edge form.
[1- Default Not related
to structural wind resistance design]
SECTION 1822
HIGH-VELOCITY HURRICANE ZONES-PILE FOUNDATIONS
1822.1 Pile foundations shall be designed and installed
on the basis of a geotechnical exploration which shall include field and/or
laboratory tests.
1822.1.1 Piles used for the support of any building or
structure shall be driven to a resistance and penetration in accordance with
the plans and/or specifications as set forth herein.
1822.1.2 Piles may be jetted under the supervision of a
professional engineer. Immediately after completion of jetting, piles shall be
driven below the depth jetted to the required resistance, but not less than 1
foot (305 mm), or to nominal refusal whichever comes first. No jetting will be
permitted that may be detrimental to existing adjacent structures or piles that
have been driven.
1822.1.3 When isolated columns, piers and other loads are
supported on piles, a minimum of three piles shall be used for such support
unless lateral bracing is provided at the pile cap to insure stability. Should
a pile group be loaded eccentrically so as to produce an overload on any pile
more than 10 percent of the allowable load, footing straps or other approved
methods shall be required to counteract the effect of eccentric loading.
1822.1.4 The minimum center-to-center spacing of piles
shall be not less than twice the average diameter of round piles or 13/4 times
the diagonal dimensions of rectangular piles but in no case less than 30 inches
(762 mm). Piles supporting structural walls shall have dowels installed to
offer sufficient resistance for lateral restraint of a grade beam.
1822.1.5 Nonfluid soil shall be considered as providing
full lateral support against column action. The portion of a pile that extends
through air, water, fluid soil or other unstable material shall be designed as
a structural column. Soils having a consistency stiffer than fluid soil may be
considered as capable of providing lateral support. Where cast-in-place piles
are used reinforcement shall extend 10 feet (3048 mm) below the plane where the
soil provides lateral restraint. Sufficient reinforcement for all types of
piles shall be provided at the junction of the pile and pile cap or grade beam
to make a suitable connection. Shells conforming to Section 1826.1 may be
considered as reinforcement.
1822.1.6 Reinforced concrete caps shall be provided for
all pile clusters and such caps shall extend laterally not less than 6 inches
(152 mm) beyond the extreme pile surface and vertically not less than 4 inches
(102 mm) below the pile butt. Pile caps may be omitted when piles are used to
support grade beams, provided that the spacing of Section 1822.1.4 is complied
with, and provided that the portions of the grade beams acting in place of the
pile cap shall be computed by a recognized method of analysis to properly carry
the loads.
1822.1.7 Piles shall be driven using an approved cushion
block consisting of material arranged to provide transmission of hammer energy
equivalent to one-piece hardwood with the grain parallel to the axis of the
pile and enclosed in a metal housing to prevent its lateral deformation between
the hammer ram and the top of the pile.
1822.1.8 Friction piles shall be driven to a minimum
penetration of 12 feet (3658 mm) below the cutoff or the existing ground,
whichever is the lower.
1822.1.9 Diesel hammers may be used for driving piles if
provided with one of the following means of determining the energy of the
hammer's blow.
1822.1.10 Closed-top diesel hammers shall be used with a
rating instrument and charts to measure the equivalent WH energy per blow of
the hammer. The equivalent WH energy as measured by the instrument shall be the
ram's weight times the equivalent ram plus an added value obtained from the
energy stored in the bounce chamber. The energy per blow shall be the
equivalent WH energy for the closed-top diesel.
1822.1.11 Open-top diesel hammers shall be equipped with
a ram stroke indictor rod that is striped in increments above the hammer body
and fastened to the body of the hammer. The energy per blow for the open top
diesel shall be computed as the ram's working stroke times the ram's weight.
1822.1.12 The load-bearing formula applicable for
single-acting pile hammers shall be used to compute the bearing capacity of the
driven pile.
1822.1.13 Followers shall be used only upon permission of
the special inspector or engineer and only where necessary to effect
installation of piles. A follower shall be of a size, shape, length, material
and weight to permit driving the pile in the desired location and to the
required depth and resistance without loss of hammer energy in the follower.
1822.1.14 Splices shall be avoided as far as practicable.
Splices shall be constructed to provide and maintain true alignment and
position of the component parts of the pile during installation and subsequent
thereto. Splices shall develop the required strength of the pile.
1822.1.15 The safe capacity of a group of friction piles
in plastic material may be determined by load testing the group to 150 percent
of the proposed group load or by the formula given in Section 1822.2. When
computed by formula, the allowable load for such a group shall be the allowable
load for one pile times the number of piles in the group times the efficiency
of the pile group determined as follows:
Where:
E =
is the efficiency
S = the
average spacing of the piles, inches
M = the
number of rows
N =
the number of piles in one row
D = the
average diameter of the pile, inches
O = arc
tan D /S , in degrees
1822.1.16 Types of piles that are not provided for in
this section shall conform to the requirements herein for the type that it most
nearly approximates, subject to such additional requirements as may be made by
the building official.
1822.1.17 Pile driving hammers shall develop a minimum of
1 foot-pound of energy per pound of pile or mandrel, but not less than 7,000
foot-pounds of energy per blow.
1822.1.18 Piles may be driven with drop or gravity
hammers provided the hammer shall weigh not less than 3,000 pounds (1362 kg)
and the fall of the hammer shall not exceed 6 feet (1829 mm).
1822.1.19 Piles shall be driven with a variation of not
more than 1/4 (6 mm) inch per foot from the vertical, or from the batter line
indicted, with a maximum variation of the head of the pile from the position
shown on the plans of not more than 3 inches (76 mm), subject to the provisions
of Section 1822.1.3.
1822.1.20 The special inspector or engineer supervising
the pile driving operations shall be required to keep an accurate record of the
material and the principal dimensions of each pile; of the weight and fall of
the hammer, if a single-acting hammer or drop hammer; the size and make,
operating pressure, length of hose, number of blows per minute and energy per
blow, if a double-acting hammer; together with the average penetration of each
pile for at least the last five blows, and the grades at tip and cut-off. A
copy of these records shall be filed with the building official and kept with
the plans.
1822.1.21 Where piling must penetrate strata offering
high resistance to driving or where jetting could cause damage, the inspector
or supervising engineer may require that the piles be set in predrilled or punched
holes. The equipment used for drilling or punching must be approved by the
special inspector or engineer, and provided that all piles shall reach their
final penetration by driving.
1822.1.22 The maximum load permitted on any driven pile
shall not exceed 36 tons unless substantiated by a load test performed at the
site, as set forth in Section 1829.
1822.1.23 The building official may require tests on any
pile where performance is questionable.
1822.1.24 Piles shall be designed and driven to develop
not less than 10 tons safe bearing capacity.
1822.1.25 In soils in which the installation of piles
causes previously installed piles to heave, accurate level marks shall be put
on all piles immediately after installation and all heaved piles shall be
reinstalled to the required resistance.
1822.1.26 Piles shall not be driven closer than 2 feet
(610 mm) nor jetted closer than 10 feet (3048 mm) to an existing building or
structure unless approved by a special inspector or engineer.
1822.2 Driving formula load. Subject to pile load
limitations contained in Sections 1823.1.8 and 1824.1.2 and in the absence of
pile load test data satisfactory to the building official, the load on a pile
shall not exceed that computed from the following driving formula:
Drop Hammer:
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Single Acting Hammers:
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Double Acting Hammers:
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Or differential in which:
A = area
of piston, square inches
p = pressure
at the hammer, pounds per square inch
P = allowable
total load, pounds
W = weight of striking part of hammer,
pounds
H = height
of fall of striking part of hammer, feet, or stroke, feet
S = average penetration per blow of not
less than the five final blows
TABLE 1823
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[1- Default Not related to structural wind resistance design]
SECTION 1823
HIGH-VELOCITY HURRICANE ZONES-WOOD PILES
1823.1 Woodpiles shall conform to ASTM D 25, Round Timber
Piles.
1823.1.1 Untreated wood piles in all cases shall be cut
off not higher than mean low water table and shall be capped with concrete.
1823.1.2 Timber piles used to support permanent
structures shall be treated in accordance with this section unless it is
established that the top of the untreated timber piles will be below lowest
ground water level assumed to exist during the life of the structure.
1823.1.3 Preservative and minimum final retention shall
be in accordance with AWPA C3.
1823.1.4 When timber piles are used in salt water, the
treatment shall conform to AWPA MP-1, MP-2 or MP-4. Pile cutoffs shall be
treated in accordance with AWPA M-4.
1823.1.4.1 All preservative-treated wood piles shall have
a metal tag, brand or other preservative treatment identification mark.
1823.1.4.2 Such mark shall identify the producer, and/or
the appropriate inspection agency, and treatment specifications or quality
mark.
1823.1.5 Wood piles which support a structure over water
may project above the water to such height as may be necessary for structural
purposes, provided that such piles used to support structures other than open
wharves, boat landings, and other similar light structures shall have been
treated in accordance with Section 1823.1.2
1823.1.6 Wood piles shall be driven with a protective
driving cap or ring when necessary to prevent brooming or splitting of the
butt. When brooming or splitting occurs, such piles shall be cut back to solid
wood before the final resistance to penetrations is measured.
1823.1.7 If required, when driving through or to hard
material or to rock, wood piles shall be fitted with a metal protective driving
cap shown satisfactory to the building official.
1823.1.8 The maximum allowable load on a round timber
pile shall be determined in accordance with Section 1822.1.22, provided the
maximum allowable stresses of timber are not exceeded.
1823.1.8.1 The allowable stresses for timber piles shall
not exceed the values in Table 1823 except as modified by Part 6 of the
National Design Specification for Wood Construction.
[1- Default Not related to structural wind resistance design]
SECTION 1824
HIGH-VELOCITY HURRICANE ZONES-PRECAST CONCRETE PILES
1824.1 Precast concrete piles shall be cast of concrete
having a compressive strength of not less than 3,000 pounds per square inch
(psi) (21 MPa) at the time of driving, and shall be reinforced with a minimum
of four longitudinal steel bars having an area of not less than 1 percent nor
more than 4 percent of the gross concrete area. All longitudinal bars shall be
of uniform size and shall be tied by not less than #2 hoops spaced 8 inches
(203 mm) in the body of the pile and not over 3 inches (76 mm) for the first 18
inches (437 mm) from both the butt and the tip. All reinforcement shall be
protected by 2 inches (51 mm) or more of concrete, except that for piles
subjected to the action of open water, waves or other severe exposure, a 3-inch
(76 mm) protective covering shall be furnished in the zone of such exposure.
For point bearing piles, the concrete area of the tip shall be not less than 75
percent of the area of the butt.
1824.1.1 All precast concrete piles shall have their date
of manufacture and the lifting points clearly marked on the pile. Concrete
piles shall not be driven until they have attained their full specification
strength as verified by tests, nor shall the piles be removed from the forms
until 50 percent of the specification strength has been attained. Piles shall
not be transported nor driven until they have been cured not less than seven
days for Type I cement and three days for Type III cement.
1824.1.2 In the absence of load tests, the maximum allowable
load per pile shall not exceed the values set forth in Table 1824.
TABLE
1824
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[1- Default Not related
to structural wind resistance design]
SECTION 1825
HIGH-VELOCITY HURRICANE ZONES-
PRESTRESSED PRECAST CONCRETE PILES
1825.1 Prestressed precast concrete piles shall conform
to Chapter 19 (High-Velocity Hurricane Zones) and to Sections 1822.1.1, 1822.2,
1824 and 1828 except as specifically detailed in this section.
1825.1.1 Prestressed concrete piles shall be cast of
concrete having a compressive strength of not less than 5,000 psi (34 MPa) at
time of driving and 3,000 psi (21 MPa) before transfer of the prestressing
force. The prestressing elements shall not be stressed initially in excess of
75 percent of ultimate strength. The elements shall transfer a compressive
stress to the concrete, after losses, of not less than 0.08 percent of the
specified strength at driving. Under loads other than handling no tension will
be permitted in the concrete.
1825.1.2 Longitudinal reinforcing shall be protected by 2
inches (51 mm) of concrete and shall be tied by #2 hoops or #5 AS&W gauge
spirals spaced at 8 inches (203 mm) in the body of piling 14 inches (356 mm) or
smaller or 9 inches (22 mm) in the body of piling 16 inches (76 mm) or larger and
not over 3 inches (76 mm) for the first 18 inches (457 mm) from both the butt
and the tip.
[1- Default Not related to structural wind resistance design]
SECTION 1826
HIGH-VELOCITY HURRICANE ZONES-CAST-IN-PLACE
1826.1 Cast-in place concrete piles shall consist of a
steel shell driven in intimate contact with the surrounding soil and left in
place and filled with concrete. Steel shells may be uniformly tapered,
step-tapered, cylindrical or a combination of such shapes and may be laterally
corrugated, spirally corrugated, longitudinally fluted or plain.
1826.1.1 Pile shells and end closures shall be of
sufficient strength and rigidity to permit their driving in keeping with the
driving method used, and to prevent harmful distortion caused by soil pressures
or the driving of adjacent piles until filled with concrete. A reduction of
cross sectional area in excess of 15 percent shall be cause for rejection. The
shells shall also be sufficiently water tight to exclude water during the
placing of concrete.
1826.1.2 The minimum diameter shall be 8 inches.
1826.1.3 Concrete for cast-in-place piles shall develop a
compressive strength of not less than 3,000 psi (21 MPa) in 28 days. The
concrete shall be deposited in a continuous operation to insure a full-sized
pile without voids or separation. Concrete shall be placed in the dry. The pile
may be sealed by depositing concrete by tremie or other approved method.
1826.1.4 Splices of shell sections shall be designed to
insure the alignment of the shells and develop the full strength of the shell
station.
1826.1.5 The load on the shell shall not exceed 25
percent of the minimum average tensile yield strength of the steel multiplied
by the area of the shell.
1826.1.5.1 Shells having a wall thickness of 0.119 inch
(3 mm) or more may be considered as carrying part of the load.
1826.1.5.2 Adequate allowance for corrosion shall be
considered in the design but not less than the outer inch of the shell
thickness shall be deducted before computing the area of the shell considered
as carrying load.
1826.1.5.3 The metal for the shells shall conform to the
Standards of Welded and Seamless Steel Pipe Piles, Grade 2, ASTM A 252, for
Hot-Rolled Carbon Steel Sheets and Strip of Structural Quality, ASTM A 570 and
Carbon Structural Steel, Cold-Rolled Sheet, ASTM A 611.
1826.1.5.4 The yield strength used in design shall be
that of the material in the fabricated shell.
1826.1.6 For friction piles, the allowable load shall be
computed at the cross section located at a point two-thirds of the embedded
length of the pile, in material providing suitable lateral support, measured
upward from the tip. The load on the concrete shall not exceed 25 percent of
the 28-day strength of the concrete multiplied by the concrete area.
1826.1.7 For end-bearing piles, the concrete area of the
critical section shall be such that the unit stress on the concrete does not
exceed 0.25 f ’c under the pile load. The area of the shell and the critical
section of the concrete shall be taken at the elevation where the pile enters
the stratum furnishing and bearing.
[1- Default Not related to structural wind resistance design]
SECTION 1827
HIGH-VELOCITY HURRICANE ZONES-ROLLED STRUCTURAL SHAPES
1827.1 Rolled structural steel piles shall conform to the
Standards for general requirements for Hot-Rolled and Cold-Finished Carbon and
Alloy Steel Bars, ASTM A 29, and Carbon Steel Bars Subject to Mechanical
Property Requirements, ASTM A 306, except that copper may be added to increase
the corrosion-resistant properties of the material.
1827.1.1 Sections of such pile of H form shall have
flange projections not exceeding 14 times the thickness of web or flange and
total flange width not less than 85 percent of the depth of the section.
1827.1.2 No section shall have a nominal thickness of
metal less than 3/8 inch (10 mm).
1827.1.3 For end-bearing piles, the allowable stress may
be determined on the basis of an allowable stress of 25 percent of the yield
value of the steel.
1827.1.4 In the absence of adequate corrosion protection,
1/16 inch (1.6 mm) shall be deducted from each face in determining the area of
the pile section.
1827.1.5 The allowable load, when used as friction piles,
shall be determined by load tests at the site.
[1- Default Not related to structural wind resistance design]
SECTION 1828
HIGH-VELOCITY HURRICANE ZONES-SPECIAL PILES OR SPECIAL CONDITIONS
1828.1 The use of types of piles or conditions not
specifically covered herein may be permitted, subject to the approval of the
building official, upon submission of acceptable test data, calculations or
other information relating to the properties and load-carrying capacity of such
piles.
[1- Default Not related to structural wind resistance design]
SECTION 1829
HIGH-VELOCITY HURRICANE ZONES-LOAD TESTS ON PILES
1829.1 Single piles tested shall be loaded to at least
twice the desired design load and should pile groups be tested, the test load
shall be not less than 11/2 times the total desired load for the group.
1829.1.1 The apparatus for applying known vertical loads
to the top of the pile shall maintain constant load under increasing
settlement, and shall apply the loads in such a way that no lateral forces or
impact will occur. Hydraulic jacks when used shall be equipped with a
calibrated pressure gauge. Uplift piles used to provide the jacking resistance
shall be a sufficient distance from the test pile so as not to influence its
behavior under test.
1829.1.2 The test load shall be applied in increments of
not more than 25 percent of the design load until the total test load has been
applied.
1829.1.3 The method for determining vertical movement
shall be subject to the approval of the building official. Readings shall be
sufficient in number to define the time settlement and rebound curve.
1829.1.4 Each load increment shall be maintained for a
minimum of 1 hour, and until the rate of settlement is less than 0.01 inch (.25
mm) per hour. The total load shall be maintained until settlement does not
exceed 0.01 (.25 mm) inch in 24 hours. Settlement readings shall be taken at
regular intervals during the test period.
1829.1.5 After the maximum load has remained on the pile
for 24 hours and final settlement readings have been taken, the pile shall be
unloaded in 50-percent decrements of design load. Rebound readings shall be
taken at regular intervals during the unloading period, and final reading taken
approximately 12 hours after the entire load has been removed.
1829.1.6 The maximum allowable pile load shall be
one-half of that load which causes a net settlement of not more than 0.005 inch
(.13 mm) per ton of test load, a gross settlement of 1 inch (25 mm) (whichever
is less) or a disproportionate increase in settlement.
1829.1.7 Control test piles shall be tested in accordance
with ASTM D 1143, Method of Testing Piles Under Axial Compressive Load. If
quick load test procedures are used, the applied test load shall be not less
than three times the working pile capacity and in accordance with the standard.
[1- Default Not related to structural wind resistance design]
SECTION 1830
HIGH-VELOCITY HURRICANE ZONES-FOUNDATION WALLS AND GRADE BEAMS
1830.1 Exterior foundation walls of buildings, where the
character of the soil is such that allowable soil loads of 1,500 pounds per
square foot (psf) (81 kN/m2) or less are used for design, shall be
poured-in-place reinforced concrete from the footing to the bottom of the first
or ground floor construction.
1830.1.1 Exterior foundation walls of building, where the
character of the soil is such that allowable soil loads of more than 1,500 psf
(71 kN/m2) are used for design, may be of unit masonry or concrete on
continuous concrete footings.
1830.1.2 Under the exterior walls of buildings of Type V
construction, in locations where extreme dampness exists, the building official
may approve isolated piers, provided such piers are as otherwise set forth in
Section 1823.1.1.
1830.2 Detailed requirements.
1830.2.1 The thickness of the foundation wall shall be
not less than 8 inches (203 mm).
1830.2.2 Where wood joist construction is used for the
first or ground floor, the thickness of the exterior foundation walls shall be
not less than 8 inches (203 mm), plus 4 inches (102 mm) for the bearing of
joists.
1830.2.3 Foundations of unit masonry supporting joists
shall be capped with 4 inches (102 mm) of concrete.
1830.3 Interior bearing walls. Interior foundation walls
shall be of the material and design as specified in Section 1830.1 except as
follows.
1830.3.1 Interior foundation walls that support stud
walls shall be exempted from the additional 4 inches (102 mm) of width required
for the bearing of joists.
1830.3.2 The use of isolated piers, girders and beams may
be substituted for interior foundation walls when designed by a registered
architect and/or engineer.
1830.4 Grade beams.
1830.4.1 Grade beams supporting loads between piles or
piers shall be reinforced concrete or structural steel protected by 2 inches
(51 mm) of concrete cover.
1830.4.2 Grade beams shall be the thickness of the wall
they support but never less than 8 inches (203 mm) nor less than set forth for
foundation walls herein.
1830.4.3 Grade beams shall be suitably designed and
reinforced around access openings and vents.
[1- Default Not related to structural wind resistance design]
SECTION 1831
HIGH-VELOCITY HURRICANE ZONES-GRADES UNDER BUILDINGS
1831.1 The grade of the ground under buildings of joist
or suspended slab construction having no basements shall not be lower than the
lowest surrounding finished lot area grade in order to prevent the accumulation
and standing of ground, storm or tide water under such buildings unless
provided with other approved means of drainage.
1831.1.1 Plans for future raising of lots shall be taken
into account in planning the grade of the ground under such buildings.
1831.1.2 The building official may establish grades under
such buildings based on present or future street or sidewalk grades abutting
the property.
[1- Default Not related to structural wind resistance design]
SECTION 1832
HIGH-VELOCITY HURRICANE ZONES-RETAINING WALLS
1832.1 All walls exceeding 24 inches (610 mm) in height
built to retain or support earth, or subject to pressure from adjoining earth,
and any surcharge shall be designed to resist the pressure to which they are
subjected, including water pressure that may exist.
[1- Default Not related
to structural wind resistance design]
SECTION 1833
HIGH-VELOCITY HURRICANE ZONES-SEAWALLS AND BULKHEADS
1833.1 All dredging, filling, excavation and waterfront
construction such as docks, piers, wharves, bridges, groins, jetties, moles,
breakwaters, seawalls, revetments, causeways, artificial nourishment of beaches
or other deposition or removal of material in all water areas within the area
of jurisdiction of this code shall be planned and designed by a professional
engineer, except as noted in Section 1833.2, in accordance with this code and
the applicable standards and requirements of the administrative authority.
1833.2 The requirement for professional design will not
be required by the building official for bulkheads, docks, piers and similar
structures constructed in conjunction with private residences on lakes, private
canals and similar water frontage not subject to wind, wave or tidal action; do
not involve unusual soil conditions, slopes or unstable soil and are not part
of a foundation or support for an above-grade structure.
[1- Default Not related
to structural wind resistance design]
SECTION 1834
HIGH-VELOCITY HURRICANE ZONES-SOIL IMPROVEMENT
1834.1 The application of soil improvement techniques
shall comply with this section.
1834.1.1 Methods of soil improvement for a specific site
shall be determined by a registered professional engineer, hereinafter referred
to as the geotechnical engineer, and such methods shall provide for field
testing as required herein.
1834.1.2 A permit shall be required prior to the
commencement of any soil improvement, and no building permit shall be issued
until it has been determined that adequate bearing capacity has been obtained
for the foundation, and the requirements of this section have been satisfied.
1834.2 Limits on application.
1834.2.1 Soil improvement shall not be permitted where
subsurface conditions consist of zones of organic materials of sufficient
quality above or below the ground water table which cannot be dispersed or
displaced to levels not exceeding 5-percent dry weight of organic content in
any undisturbed sample.
1834.2.2 Dynamic compaction, vibrocompaction, preloading,
surcharging or other similar methods of soil improvements shall not be
permitted near or within coastal areas subject to storm surge, scour or other
forms of water erosion without suitable protection provided for the building
foundation.
1834.3 Required testing.
1834.3.1 A rational program of field tests and soil
analyses shall be part of the soil improvement treatment.
1834.3.2 Such tests shall determine the soil
characteristics after treatment, and the results of the tests shall demonstrate
whether the subsurface improvement has increased the bearing capacity of the
soil to that which is capable of safely supporting the proposed construction.
1834.3.3 The testing shall be performed in accordance
with the provisions of ASTM D 1586, Standard Penetration Test; ASTM D 3441,
Static Cone Soundings; or by Menard Pressuremeter; Dilatometer or other on-site
tests recognized by the industry.
1834.3.4 The test results shall be used to determine the
achieved bearing capacity and the anticipated settlement.
1834.4 Requirements for acceptance. The efficacy of any
application of soil improvement techniques shall be verified by appropriate
calculations, testing and documentation as required in this section.
1834.4.1 All organics, including any organic lens, shall
be displaced by the injection of sand or other suitable fill material, or
otherwise dispersed in accordance with the provisions of this section, to
levels not exceeding 5 percent by weight of organic content in any undisturbed
sample.
1834.4.2 Complete documentation of required tests shall
be required, and shall included as a minimum, but shall not be limited to:
1. A
description of the stratigraphy and densification required and
2. Foundation
bearing capacity and settlement analysis performed by an independent testing
laboratory.
3. The
anticipated settlement potential under superimposed loads shall be acknowledged
and accepted by the engineer of record in writing prior to issuance of a
building permit.
4. The
results of testing to determine subsurface conditions shall be retained by the
geotechnical engineer and submitted to the building official upon request.
[1- Default Not related
to structural wind resistance design]