preclude the slivers or shavings cut by the sleeve producing objectionable
shakes or splinters. Full bearing of timber on timber shall be provided
and air pockets or cushions in the sleeves avoided. Correction of damage
or impairment to the protective treated shell, as a result of trimming or
driving the sleeve, shall be in accordance with AWPA M4.
3.1.6
Surface Treatment
After piles have been driven and cut off, all cut, bored, and dapped
surfaces shall be treated as specified in AWPA M4.
3.2
PILE DRIVING EQUIPMENT
3.2.1
Pile Hammers
The hammer furnished shall have a capacity at least equal to the hammer
manufacturer's recommendation for the total weight of pile and character of
subsurface material to be encountered. For piles of any length, the
maximum driving energy of the hammer shall be 27.1 kN-m (20,000
foot-pounds) 20,000 foot-pounds.
3.2.2
Driving Helmets and Pile Cushions
A driving helmet or cap, including a pile cushion or cap block, shall be
used between the top of the pile and the ram to prevent impact damage to
the pile. The driving helmet, or cap and pile cushion combination, shall
be capable of protecting the head of the pile, minimizing energy
absorption, and transmitting hammer energy uniformly and consistently
during the entire driving period. The driving helmet or cap shall fit
snugly on the top of the pile so that the energy transmitted to the pile is
uniformly distributed over the entire surface of the pile head. During the
test-pile period, the Contractor shall demonstrate to the Contracting
Officer that the equipment to be used on the project performs the above
functions. The pile cushion may be a solid or laminated softwood block
with the grain parallel to the pile axis and enclosed in a close-fitting
steel housing. The thickness of block shall be suitable for the length of
pile to be driven and the character of subsurface material to be
encountered. Generally, thicker blocks are required for longer piles and
softer subsurface material.
3.2.3
Capblocks
The capblock used between the driving cap and the hammer ram may be of
solid hardwood block with grain parallel to the pile axis and enclosed in a
close fitting steel housing or may consist of aluminum and approved
industrial type plastic laminate discs stacked alternately in a steel
housing. Steel plates shall be used at the top and the bottom of the
capblock. Where the block is other than that specified above, the
Contractor shall submit to the Contracting Officer, at least 2 weeks before
the start of test pile driving operations, detailed drawings of the
proposed capblock accompanied by records of its successful use. If a wood
capblock is used, it shall not be replaced during the final driving of any
pile. The use of small wood blocks, wood chips, rope, or other material
permitting excessive loss of hammer energy will not be permitted.
SECTION 02457A
Page 12
Previous Page
