01 July 1997
(c) Thermal Piles. These piles are designed to ensure long-term thermal stability of the
foundation by preventing degradation of permafrost in low temperature regions. Details of these piles are
provided in TM 5-582-4.
b. Material Specifications.
(1) Timber Piles. Most timber piles are softwoods such as varieties of Douglas fir and southern
(a) Physical specifications of round timber piles shall conform to ASTM D 25. Other conformed
sources are listed in appendix B.
(b) Specifications shall limit defects such as checks, splits, shakes, and knots because these
defects can be made more severe by driving. The inner exposed surfaces of treated piles can be subject to
decay and attack by insects. A check is a longitudinal separation across the growth rings of a pile starting
from the pile surface extending partially into the pile. A split is a check that extends through the pile. A
shake is a separation between growth rings of the pile.
(c) Timber piles shall be free of large or loose knots, splits, decay, and sharp bends.
(d) Bark should be removed from timber piles where they are designed as friction piles because
a slip can occur between the bark and the trunk. Removal of the bark also improves penetration of
(e) Timber piles shall have a uniform taper from butt to the tip. The piles should be sufficiently
straight that a line from the center of the pile at the butt to the center of the tip shall lie within the body of the
(f) Dimensions should be specified to satisfy design requirements. Some specified dimensions
may not be fulfilled because the pile may not be driven to the full ordered length. The pile butt in this case
may be less than that specified.
(g) Specifications may require the pile tips and butts to be protected with a steel shoe or special
fittings, figure 1-2. Steel bands may also be attached at specified intervals along the pile length. This
protection helps to prevent the pile from splitting or brooming while driving.
(2) Concrete Piles. Materials consist of concrete reinforcement steel, steel casing, structural steel
cores, grout, anchors, and splices.
(a) Material specifications should conform to ACI Committee 543 R-74 reaffirmed in 1980.
Piles received from the manufacturer should be accompanied with an inspection report so that design
requirements for the piles can be confirmed.
(b) Dimensions should be as specified by the inspection report. Corners and edges of square
piles shall be chamfered. The width of the face of the chamfer should not exceed 1.5 inches so that the
dimension of the side is not reduced more than 2.0 inches.
(c) Tip protection such as steel H, pipe projections, or steel shoes shall be cast into the pile tips
and conform to the specifications.
(3) Steel Piles. Pipe piles may be specified according to grade by ASTM A 252. H-piles may be
specified according to ASTM A 36 or ASTM A 572. Laboratory reports must be provided with the piles to
ensure that piles will meet design requirements.