upward stroke of the ram] [for differential-type hammer, there is a slight
rise of the hammer base during each upward stroke]. The pile cushion or
capblock shall be replaced whenever it becomes damaged, split, highly
compressed, charred or burned, or has become spongy or deteriorated in any
manner. The use of small wood blocks, wood chips, rope, or other material
permitting excessive loss of hammer energy will not be permitted. The
Contracting Officer shall be notified, and will determine what procedure
shall be followed, if a pile reaches the "calculated" pile tip elevation
without reaching the required driving resistance; or if the required
driving resistance is reached before the "calculated" pile tip elevation.
3.1.3
Tolerances in Driving
Piles shall be driven with a variation of not more than 20 mm/meter 1/4
inch/foot of pile length from the vertical for plumb piles or more than 40
mm/meter 1/2 inch/foot of pile length from the required angle for batter
piles. Butts shall be within 100 mm 4 inches of the location indicated.
Manipulation of piles to force them into position will not be permitted.
All piles shall be checked by the Contractor for heave. Piles found to
have heaved shall be redriven to the required tip elevation. Piles
damaged, mislocated, or driven out of alignment shall be replaced or
additional piles driven as directed.
3.1.4
Jetting
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NOTE: Jetting should generally not be permitted for:
a. Piles dependent on side friction in
fine-grained, low-permeability soils (high clay or
silt content) where considerable time is required
for the soil to reconsolidate around the piles.
b.
Piles subject to uplift.
c.
Piles adjacent to existing structures.
d. Piles in closely spaced clusters unless the load
capacity is confirmed by test and unless all jetting
is done before final driving of any pile in the
cluster.
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Jetting of piles [may be used when permitted by the Contracting Officer]
[will be permitted by the Contracting Officer as indicated] [will not be
permitted]. [Jetting shall be discontinued when the pile tip is
approximately 1.5 meters 5 feet above the "calculated" pile tip elevation
and the final 1.5 meters 5 feet of penetration shall be made by driving.
Before commencing with the driving of the final 1.5 meters 5 feet, the pile
shall be firmly seated in place by the application of a number of reduced
energy hammer blows.]
3.1.5
Splices
Pile splices shall consist of steel pile having a wall thickness of not
less than 6 mm 1/4 inch, a diameter approximating that of the pile at the
plane of splicing but a minimum of 225 mm 9 inches, and a length of not
less than 450 mm 1.5 feet above and below the joint. Before the sleeves
are driven on them, piles to be spliced shall be trimmed sufficiently to
SECTION 02457A
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