New Jersey Administrative Code › Title 19 - OTHER AGENCIES › NEW JERSEY MEADOWLANDS COMMISSION › Chapter 6 - BUILDING CODE › Subchapter 2 - FOUNDATIONS › Section 19:6-2.28 - Foundation piers

Current through Register Vol. 56, No. 14, July 15, 2024
(a) Foundation
				  piers shall be designed as columns. Reinforced concrete, and reinforced and
				  unreinforced masonry piers shall be designed in accordance with the
				  requirements of this subchapter:
1. Lateral
				  support: The equivalent unbraced length of a pier supported by lateral soil
				  pressure may be determined by a recognized method of elastic analysis.
				  Alternatively, such a pier may be assumed to be hinged, but laterally braced at
				  intervals equal to the full height of the pier or eight times the least lateral
				  dimension of the pier, whichever is the lesser value.
2. Unreinforced concrete piers: Where
				  unreinforced concrete piers are used, the allowable compressive stress shall
				  not exceed 0.25 c and the center of cross section of the pier at any level
				  shall not deviate from the line of action of the resultant of all forces (which
				  line of action shall consider the eccentricities due to all loads and moments
				  acting on the pier) by an amount more than 1/60 of its height or 1/10 of its
				  least lateral dimensions, or for greater eccentricities, piers shall be
				  reinforced.
3. Metal shells: Where
				  piers are encased by a metal shell, the shell may be considered as contributing
				  to the structural strength of the pier provided that the thickness is 1/8 inch
				  or greater, and subject to the following requirements:
i. Where boring records or site conditions
				  indicate possible deleterious action on the shell, where any portion of the
				  shell is embedded in ash, cinder fill or garbage fill, where the encased piers
				  are used for support of chemical plants, piles of coal, or under other
				  conditions conducive to chemical seepage or corrosive action, or where the
				  encased piers are used for support of electrical generating plants, the metal
				  shells shall be protected against deterioration by encasement, coating, or
				  other device acceptable to the chief engineer.
ii. The area of the metal section of the
				  shell multiplied by the efficiency of the horizontal joints shall be considered
				  as equivalent vertical reinforcement of the pier. The area of the metal section
				  of the shell multiplied by the efficiency of the vertical joints shall be
				  considered as equivalent spiral reinforcement of the pier.
4. Minimum dimensions: The provisions of
				  paragraph 5 below shall apply. In addition, the plan dimensions of the pier
				  shall not be less than those of the column above.
5. Filling: The provisions of paragraphs 1
				  and 2 of this section shall apply only where the fill (or backfill) is placed
				  around the pier as controlled fill in such a way that the level of the fill is
				  raised uniformly around the entire perimeter of the pier. Where the fill
				  operation is not raised uniformly, the least lateral dimension of a foundation
				  pier shall be 24 inches and the pier shall be proportioned for lateral pressure
				  equal to the pressure of a differential height of fill equal to five feet,
				  applied simultaneously with the other loads on the pier specified in this
				  subchapter.