New Jersey Administrative Code › Title 19 - OTHER AGENCIES › NEW JERSEY MEADOWLANDS COMMISSION › Chapter 6 - BUILDING CODE › Subchapter 2 - FOUNDATIONS › Section 19:6-2.52 - Compacted concrete piles

Current through Register Vol. 56, No. 14, July 15, 2024
(a) A "compacted
				  concrete pile" shall denote a concrete pile formed with an enlarged base in
				  which the concrete in the base is placed in small batches that are compacted
				  prior to attaining an initial set. The concrete in the shaft of the pile shall
				  be placed into a shell as specified in section 51 of this subchapter for
				  cast-in-place concrete piles.
(b)
				  Concrete for compacted concrete piles shall conform to the requirements of this
				  subchapter. Concrete to be compacted shall have a minimum compressible strength
				  at the age of 28 days of 4,000 psi and shall be mixed with sufficient water to
				  permit hydration of the cement, but the slump shall be zero. The concrete shall
				  be placed and compacted before initial set can occur. Non-compacted concrete,
				  if used for the pile shafts, shall conform to the requirements of cast-in-place
				  concrete piles.
(c) Minimum spacing
				  between compacted concrete piles shall be four feet six inches center-to-center
				  except that where the shafts of such piles are cased for their full length,
				  this spacing may be reduced to three feet six inches. Where a question exists
				  as to possible damage to adjacent previously driven piles, these minimums shall
				  be increased.
(d) Rules on
				  installation are:
1. The base shall be formed
				  by ramming concrete in batches of approximately five cubic feet or less, from a
				  drive casing and into the soil. Unless specifically otherwise permitted by the
				  chief engineer, a minimum of 20 blows of at least 140,000 foot pounds per blow
				  shall be required for extrusion of the last five cubic feet of concrete. The
				  total quantity of concrete extruded from the drive casing to form the base
				  shall be equal to or greater than the quantity so extruded in the case of the
				  nearest successful application test pile, except that a compactive effort in
				  excess of 30 blows, each of 140,000 foot pounds, will not be required for
				  extrusion of the last five cubic feet.
2. After the expanded base has been formed,
				  the shaft shall be constructed. Where a cased shaft is to be used, a steel
				  shell shall be inserted into the drive casing and anchored to the expanded base
				  by placing a fresh charge of concrete in the shell and driving it into the
				  base. The shell may then be filled with concrete to cutoff elevation after the
				  removal of the drive casing, in accordance with the provisions relating to
				  cast-in-place concrete piles. Any annular space remaining between the shell and
				  surrounding soil shall be suitably filled to assure proper lateral support of
				  the shaft, unless there is sufficient recovery of the ground to provide the
				  necessary support.
3. The outside
				  diameter of the permanent shaft shall not be more than four inches less than
				  the inside diameter of the drive casing.
4. No concrete shall be placed in the pile
				  shafts until all piles within a radius of 15 feet or within the heave range
				  have been driven.