The old methods (i.e. Gates, FDOT, ENR, and Modified ENR) gave good
estimates of the Davisson capacity for piles with Davisson capacity less than
200 tons (1779 kN).
The Gates formula, when used separately for Davisson capacity larger than
1779 kN or less than 1779 kN, may have comparable accuracy (COV’s) with
the modern methods.
For ASD design with dynamic methods, the following safety factors are
recommended to meet a probability of failure of 0.62 ~ 2.50 %: 1.8, 2.0 and
2.5 for CAPWAP, PDA, and Paikowsky’s energy method at EOD, and 2.25,
2.5 and 3.5 at BOR, respectively.
Currently, a safety factor of 2.5 is used for
CAPWAP, PDA, and Paikowsky’s method, for both, BOR, and EOD.
driving formulas are usually applied at EOD only, and safety factors of 1.9,
14.0, 11.0, and 2.0 are recommended for FDOT, ENR, modified ENR, and
Gates formulas, respectively.
The results presented in this study reflect the pile driving history of Florida.
number of piles considered is based on the availability of dynamic and static load test