Section 27-688
§ 27-688 Administrative requirements. (a) Identification of piles. A
plan showing clearly the designation of all piles by an identifying
system shall be filed with the commissioner prior to installation of
such piles. All detailed records for individual piles shall bear an
identification corresponding to that shown on the plan. A copy of such
plan shall be available at the site for inspection at all times.
(b) Record of pile driving. A record of the penetration and behavior
of each pile during installation shall be kept by the architect or
engineer designated in section 27-721 of article thirteen of this
subchapter. Such records shall be prepared on forms furnished by, or
satisfactory to, the commissioner and, upon the completion of pile
installation, shall be filed with the commissioner together with the
records of any additional borings or subsurface information obtained
during installation of the piles, and plans showing any deviations of
the pile or related constructions (including any corrective measures)
from the details and locations shown on the approved plans. Inspection
of piling and pile load tests shall conform to the requirements of
section 27-721 of article thirteen of this subchapter.
Section 27-689
§ 27-689 Minimum pile penetrations. (a) Required by soil bearing
capacity. The provisions of paragraph one of subdivision (b) of section
27-700 of article eight of this subchapter shall apply.
(b) Required for lateral restraint. The provisions of section 27-694
of this article shall apply.
(c) Piles located near a lot line. Piles located near a lot line shall
be designed on the assumption that the adjacent lot will be excavated to
a depth of ten feet below the nearest legally established curb level.
Where such excavation would reduce the embedded length of the pile, the
portion of the pile exposed shall be considered as providing no lateral
or vertical support, and the load-carrying determination in accordance
with the provisions of article eight of this subchapter shall be made
after the resistance offered by the soil that is subject to potential
excavation has been discounted.
Section 27-690
§ 27-690 Use of existing piles at demolished structures. Piles left in
place where a structure has been demolished shall not be used for the
support of new construction unless satisfactory evidence, including load
or hammer testing of representative piles, can be produced indicating
the capacity, length, and driving conditions of the piles. The load
bearing value for such existing piles shall be the least of the values
indicated by: (1) the load or hammer test, (2) the capacity of the pile
as a structural member, and (3) the allowable bearing pressure on the
soil underlying the pile tips, all in accordance with the provisions of
article eight of this subchapter.
Section 27-691
§ 27-691 Tolerance and modification of design due to field conditions.
(a) Tolerance in alignment of the pile axis. If the axis of any pile is
installed out of plumb or deviates from the specified batter by more
than four per cent of the pile length, the design of the foundation
shall be modified as may be necessary to resist the resulting vertical
and lateral forces. In types of piles for which subsurface inspection is
not possible, this determination shall be made on the exposed section of
the pile, which section, at the time of checking axial alignment, shall
not be less than two feet. In piles which can be checked for axial
alignment below the ground surface, the sweep of the pile axis shall not
exceed four per cent of the embedded length.
(b) Tolerance in location of the head of the pile. A tolerance of
three inches from the designed location shall be permitted in the
installation of each pile, without reduction in load capacity of the
pile group. Where piles are installed out of position in excess of this
amount, the true loading on such piles shall be analytically determined
from a survey which defines the actual location of the piles as driven,
and using the actual eccentricity in the pile group with respect to the
line of action of the applied load. If the total load on any pile, so
determined, is in excess of one hundred ten per cent of the allowable
load bearing capacity, correction shall be made by installing additional
piles or by other methods of load distribution, as required to reduce
the maximum pile load to one hundred ten per cent of the capacity.
(c) Bent piles. Where piles have been bent during installation, and
the amount of the bend exceeds the allowable tolerance for alignment of
the pile axis in subdivision (a) of this section, the condition shall be
investigated and, where required, correction made by the installation of
additional piles, by strengthening the bent piles, by reduction in
capacity or other means acceptable to the commissioner.
Section 27-692
§ 27-692 Minimum spacing of piles. Piles shall be spaced to meet the
following requirements:
(1) Spacing of piles shall provide for adequate distribution of the
load on the pile group to the supporting soil, in accordance with the
provisions of subdivision (b) of section 27-700 of article eight of this
subchapter.
(2) In no case shall the minimum center-to-center spacing of piles be
less than twenty-four inches, nor less than the values for specific
types of piling as indicated in article ten of this subchapter. Unless
special measures are taken to assure that piles will penetrate
sufficiently to meet the requirements of section 27-689 of this article
without interfering with or intersecting each other, the minimum
center-to-center spacing of piles shall be twice the average diameter of
the butt for round piles; one and three-quarters times the diagonal for
rectangular piles; or, for taper piles, twice the diameter at a level
two-thirds of the pile length measured up from the tip. In cases of
practical difficulty, the spacing of new piles from existing piles under
an adjacent building may be less than the above values provided that the
requirements relating to minimum embedment and pile interference are
satisfied and that the soil under the proposed and existing buildings is
not overloaded by the closer pile grouping.
Section 27-693
§ 27-693 Minimum section. Except as provided in article ten of this
subchapter for timber piles, no tapered pile shall be less than six
inches in diameter at any section, nor have less than an eight inch
diameter at cutoff. The taper of any tapered section may be uniform or
may occur in steps. No pile of uniform section shall have a diameter of
less than eight inches, or, if not circular, a dimension of less than
seven and one-half inches. Tapered shoes or points of lesser dimensions
may be attached to the tips of piles.
Section 27-694
§ 27-694 Capping and bracing of piles. (a) Capping of piles.
(1) EMBEDMENT. Tops of all piles shall be embedded at least three
inches in concrete caps. Such concrete shall conform to the provisions
of article five of subchapter ten of this chapter and shall extend at
least four inches beyond the edge of all piles. Alternatively, and only
where the piles project above the future grade and will be readily
accessible for visual inspection at all times, the tops of the piles may
be capped with timber or steel caps, which shall be connected to the
piles. Cap plates will not be required for steel H piles embedded in a
reinforced concrete cap. Inspection of pile caps shall be as required in
section 27-722 of article thirteen of this subchapter.
(2) UPLIFT. Where piles are subject to uplift, they shall be anchored
into the cap to resist at least one and one-half times the amount of
such uplift without exceeding the basic allowable stresses as
established in subchapter ten.
(3) REINFORCEMENT. Reinforcement shall be placed to provide at least
three inches of clear cover, measured to the surface of the pile cap
that is in contact with the ground. All reinforcement adjacent to timber
or concrete piling shall have a minimum of one inch of concrete
protection. Reinforcement shall extend to within four inches of the
edges of the pile cap.
(4) DESIGN. Except as modified above, concrete pile caps shall be
designed in accordance with the provisions of reference standard RS
10-3.
(b) Bracing of piles. Except for short piles as described in
subdivision (c) of this section, every pile shall be laterally braced to
conform with one or more of the following provisions:
(1) RIGID CAP. Three or more piles connected by a rigid cap shall be
considered as being braced provided that the piles are located in radial
directions from the centroid of the group not less than sixty degrees
apart (within a tolerance of three inches in location of the pile.) A
two-pile group, in a rigid cap, shall be considered to be braced along
the axis connecting the two piles.
(2) BRACE BEAMS. Piles may be braced by the use of brace beams or ties
rigidly connecting to at least two other piles in radial directions not
less than sixty degrees nor more than one hundred twenty degrees apart.
Concrete brace beams shall have minimum dimensions of one-twentieth of
the clear distance between pile caps, but not less than eight inches.
All brace beams shall be proportioned to resist a minimum axial load
equal to three per cent of the total axial load capacity of the piles
that are to be braced by that beam, plus the moment due to any
eccentricity between the centroid of the pile group and the line of
action of the applied load. Where underlain by soil of class 9-65, 10-65
or 11-65, brace beams shall be proportioned to support the weight of
soil, slab-on-ground, and live load on the slab-on-ground that is
contained within vertical planes projected upward from the lateral
limits of the brace beam. The design of brace beams to resist these
loads shall conform to the provision of subchapter ten of this chapter.
(3) CONCRETE SLAB-ON-GRADE. A continuous concrete slab or mat on
grade, that is five inches or more in thickness and reinforced, and that
extends at least forty feet in each direction and is anchored to the
pile caps (or in which the piles are embedded at least three inches),
may be used in lieu of brace beams for bracing of pile caps, providing
that the slab is supported on material having an allowable bearing
pressure of one and one-half tons per square foot or better and such
material is not underlain by nominally unsatisfactory bearing materials.
(4) OTHER MEANS. Piles may be braced by anchors, anchor wall, or other
means acceptable to the commissioner.
(5) FLOOR SYSTEM. Single-pile or two-pile groups or a single line of
piles may be considered to be adequately braced if connected to, and
braced by, a self supporting floor system provided: (1) that the details
and dimensions of the floor and the wall or pier are of adequate
strength to resist lateral displacement of the pile cap under conditions
of maximum eccentricity of the applied load; and (2) that the wall or
pier is braced until connection of the floor framing is made and the
flooring (or slab) is in place.
(6) SPECIAL REQUIREMENTS FOR BRACING BATTER PILES. The provisions of
paragraphs one through five of this subdivision above shall apply. In
addition, provisions shall be made to oppose the lateral thrust
resulting from the pile inclination.
(c) Bracing of short piles.
(1) All pile caps supported by piles that penetrate less than ten feet
below cutoff level or less than ten feet below ground level shall be
braced against lateral movement. Such bracing may consist of connection
to other pile caps that encompass piles embedded more than ten feet
below those levels; the use of suitable anchors, connection to a
slab-on-grade or the floor system as described in paragraphs three and
five of subdivision (b) of this section, or by other equivalent means.
The heads of the piles shall be fixed in the cap. In no event shall more
than fifty percent of the piles in the foundation of any building
penetrate less than ten feet below cut-off-level or less than ten feet
below ground level.
(2) Where the embedded length of piles located near a lot line would
be reduced to less than ten feet by excavation of the adjacent site to a
depth of ten feet below the nearest established curb level, the
provisions of paragraph one of this subdivision shall apply.
Section 27-695
§ 27-695 Splicing of piles. Splices shall be constructed so as to
provide and maintain true alignment and position of the component parts
of the pile during installation and subsequent thereto, and shall be of
adequate strength to transmit the vertical and lateral loads (including
tensions) and the moments occurring in the pile section at the location
of the splice without exceeding the allowable stresses for such
materials as established in subdivision (a) of section 27-700 of article
eight of this subchapter. Except for piles which can be visually
inspected after driving, splices shall develop at least fifty per cent
of the capacity of the pile in bending. In addition, all pile splices in
the upper ten feet of the pile section shall be capable of resisting (at
allowable working stresses) the moment and shear that would result from
an assumed eccentricity of the pile load of three inches, or the pile
shall be braced in accordance with the provisions of section 27-694 of
article seven of this subchapter to other piles that do not have splices
in the upper ten feet of embedment. For piles located near a lot line,
the embedded length of such piles shall be determined on the basis that
the adjacent site will be excavated to a depth of ten feet below the
nearest established curb level.
Section 27-696
§ 27-696 General requirements for installation of piles. (a)
Protection of adjacent property. Piles shall be installed with adequate
provision for the protection of adjacent buildings and property.
(b) Protection of the pile during installation. Piling shall be
handled and installed to the required penetration and resistance by
methods that leave their strength unimpaired and that develop and retain
the required load-bearing resistance. Any damaged pile shall be
satisfactorily repaired or the pile shall be rejected. Subject to the
approval of the commissioner, damaged piles may be used at a fraction of
the design load as determined by the architect or engineer in lieu of
repair or rejection.
(c) Protection of pile materials after installation. Where boring
records or site conditions indicate possible deleterious action on pile
materials due to soil constituents, changing water levels, or other
causes, such materials shall be adequately protected by preservatives or
encasements that will not be rendered ineffective by driving and that
will prevent such deleterious action. The following specific provisions
shall apply:
(1) Untreated timber piles shall not be used unless the top level of
the pile is below the permanent water table. The permanent water table
level shall not be assumed higher than the invert level of any sewer,
drain, or subsurface structure in the adjacent streets, nor higher than
the water level at the site resulting from the lowest drawdown of wells
or sumps, but in no case shall untreated timber piles be used where the
cut-off level is less than ten feet below the adjacent legal grade.
Where treated piles are required, preservative treatment shall consist
of impregnation with creosote or a creosote solution or, for piles
entirely embedded below grade, a pentachlorophenal solution may be used.
Treatment shall be in accordance with all requirements of reference
standard RS 11-6.
(2) Piles installed in ash or garbage fills, cinder fills, or which
are free-standing in or near a seawater environment, or which are used
for the support of chemical plants, coal piles or under similar
conditions of chemical seepage or aggressive action, or which are used
for support of electrical generating plants, shall be investigated
regarding the need for special protective treatment and, where
protective treatment is indicated, shall be protected against
deterioration by encasement, coating, or other device acceptable to the
commissioner.
(d) Equipment. Equipment and methods for installing piles shall be
such that piles are installed in their proper position and alignment,
without damage. Equipment shall be maintained in good repair.
Section 27-697
§ 27-697 Use of uncased concrete pile shafts. The use of uncased
shafts (i.e., where the concrete of the pile shaft is in direct contact
with the surrounding soil) will be permitted under the following
conditions:
(a) For bored piles. Where the bored hole is maintained free of water
before and during placement of the concrete and the sides and bottom can
be inspected prior to such placement, and provided that no displacement
pile shall be installed within fifteen feet of any bored pile.
(b) For driven piles (including all piles wherein installation
utilizes a temporary casing). The maximum length of the uncased shaft
shall be limited to ten feet unless otherwise permitted by the
commissioner. Uncased shafts will be permitted to be formed in soil
below the water table but shall not be formed in any soil of class 9-65
that is of medium or soft consistency; in any soil of class 10-65 that
is of medium or loose density; or in any soil of class 11-65.
Section 27-698
§ 27-698 Where more than one pile type, pile capacity, or method of
pile installation is used. Wherever it is proposed to: (1) construct a
foundation for a building utilizing piles of more than one type or
capacity; (2) modify an existing foundation by the addition of piles of
a type or capacity other than those of the existing piling; (3)
construct or modify a foundation utilizing different methods or more
than one method of installation, or using different types or capacities
of equipment (such as different types of hammers having markedly
different striking energies or speeds); or (4) support part of a
building on piles and part on footings, the several parts of the
building supported on the different types, capacities, or modes of
piling shall be separated by suitable joints providing for differential
movement, or a report shall be submitted by the architect or engineer
establishing to the satisfaction of the commissioner that the proposed
construction is adequate and safe, and showing that the probable
settlements and differential settlements to be expected will not result
in instability of the building or stresses in the structure in excess of
the allowable values established in subchapter ten of this chapter. The
provisions of subdivision (d) of section 27-700 of article eight of this
subchapter relating to required load tests shall apply separately and
distinctly to each different type or capacity of piling, method of
installation, or type or capacity of equipment used, except where
analysis of the probable, comparative behavior of the different types or
capacities of the piles or the methods of installation indicates that
data on one type or capacity of pile permits a reliable extrapolation of
the probable behavior of the piles of other types and capacities.
Section 27-699
§ 27-699 Pile materials. The provisions of sections 27-580 and 27-588
of article one of subchapter ten of this chapter relating to
"classification of materials, assemblies and methods of construction"
and to the use of "used and unidentified materials" shall apply.
To the extent possible under law, Friends of Devin Balkind for Public Advocate has waived all copyright and related or neighboring rights to New York City Administrative Code. This work is published from: United States.
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