CEMP-E
EI 02G001
01 July 1997
(1)
Determine the design load Rd for a given pile in pounds.
(2)
this:
(a)
This value can be given either in the design plans, or computed by the
methods referred to in Paragraph 2-11b.
(b)
The design load Rd can be multiplied by a factor of safety, according to the
formula
Ru = N Rd
where
Ru = ultimate pile resistance, pounds
N = factor of safety
= 2.0 when static load tests are required
= 2.5 when the pile driving analyzer and wave equation analysis are
required
= 3.0 when only the wave equation analysis is required. (if a factor of
safety has been established for the piles elsewhere, then use that
value.)
If values from both (a) and (b) are available, then use the greater of the two.
(3)
Divide the ultimate resistance value by the pile area using the formula
Su = Ru/Ap
where
Su = ultimate pile resistance per unit area, psi. This
value should not fall below 900 psi with concrete
piles or 9,000 psi with steel piles for subsequent
computational purposes
As = pile cross-sectional area, square inches
(4)
Compute the minimum rated striking energy for the pile hammer for the particular
pile at 10 blows per inch. The formula used depends upon whether the pile is steel or
concrete.
Er 10BPI = As Su / (21.36 e(-Su/3690)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Concrete Piles
Er 10BPI = As Su1.62/5400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steel Piles
where
Er 10BPI =
minimum hammer rated striking energy at 10 blows per inch of
resistance, foot-pounds
Figure 2-1b. Preliminary Method for Sizing Hammers for Concrete and Steel Piles, Metric Units
(after Florida DOT Specification, Section 455).
2-7
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