Section 27-668
§ 27-668 Soil bearing pressures. The loads to be used in computing the
bearing pressures on materials directly underlying footings shall be the
total column, pier, or wall reactions determined in accordance with the
provisions of subchapter nine of this chapter, on the basis of reduced
live load; plus the weight of the foundations; plus the weight of any
soil, fill, and slabs on grade that is included within vertical planes
projected upward from the extreme limits of the footing to the final
ground surface. Live load on grade, or on slabs on grade, within these
limits shall also be included. Impact loads shall be considered in
accordance with the provisions of section 27-673 of this article.
Section 27-669
§ 27-669 Pile reactions. The loads to be used in computing pile
reactions shall be determined as provided in section 27-668 of this
article except that where piles penetrate fill, clay, silt, peat, or
similar compressible strata, the pile loads shall be increased by the
amount of drag exerted by such material, and by any overlaying strata,
during consolidation. Computation of the amount of drag shall consider
the amount of added fill, the amount of shear strain between pile (or
group) and the soil, the ratio of vertical to horizontal pressure in the
soil, and the arrangement of the piles. The soil surrounding or
underlying the pile cap shall not be considered as providing any
vertical support for the cap.
Section 27-670
§ 27-670 Lateral loads. (a) Earth and ground water pressure. Every
foundation wall or other wall serving as a retaining structure shall be
designed to resist, in addition to the vertical loads acting thereon,
the incident lateral earth pressures and surcharges, plus hydrostatic
pressures corresponding to the maximum probable ground water level.
Retaining walls shall be designed to resist at least the superimposed
effects of the total static lateral soil pressure, excluding the
pressure caused by any temporary surcharge, plus an earthquake force of
0.045wsh¥ (horizontal backfill surface), where ws equals unit weight of
soil and h equals wall height. Surcharges which are applied over
extended periods of time shall be included in the total static lateral
soil pressure and their earthquake lateral force shall be computed and
added to the force of 0.045wsh¥. The earthquake force from backfill
shall be distributed as an inverse triangle over the height of the wall.
The point of application of the earthquake force from an extended
duration surcharge shall be determined on an individual case basis. If
the backfill consists of loose saturated granular soil, consideration
shall be given to the potential liquefication of the backfill during the
seismic loading using reference standard RS 9-6.
(b) Wind and other superstructure loads. Provision shall be made to
resist lateral loads imposed on the superstructure due to wind or other
causes.
(c) Soil movements. Buildings shall not be constructed in areas where
the soil is subject to lateral movements unless positive provision is
made to prevent such movements.
Section 27-671
§ 27-671 Eccentricities. Eccentricity of loading in foundations,
including eccentricity of loading on the bases of retaining walls, shall
be investigated and the maximum soil pressure or pile load (considering
eccentricity) shall be kept within the safe capacity thereof as
established in articles four and eight of this subchapter. Soil pressure
and pile load due to eccentricity shall be computed on the basis of
straight line distribution of foundation reaction. However, other modes
of distribution of the foundation reaction may be assumed, subject to
the approval of the commissioner, if it can be demonstrated that the
pile and/or soil is capable of sufficient plastic deformation to develop
such mode of distribution without failure.
Section 27-672
§ 27-672 Uplift forces. Uplift and overturning forces due to wind and
hydrostatic pressure shall be considered.
Section 27-673
§ 27-673 Impact. Impact forces may be neglected in the design of
foundations, except for foundations bearing on loose granular soils, or,
regardless of the type of soil material, for foundations supporting
cranes, heavy machinery, and moving equipment, or where the ratio of the
live load causing impact to the total of the reactions from live load
applied without impact plus dead load exceeds one-third.
Section 27-674
§ 27-674 Stability. The provisions of article twelve of this
subchapter 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.
Special thanks to Benjarmin Kallos and Thom Neale who made this content publicly available as a bulk download.