Example Problem 6.14 A pile that has a diameter of 1.0 ft (0.3 m) and that is 20 ft (6 m)
long is driven into a uniform clay deposit that has a medium consistency. The clay has a uniform
undrained shear strength s u = 750 psf (36 kPa) and a total unit weight = 125 pcf (20 kN/m).
Consolidated undrained triaxial compression tests with pore water pressure measurements were
also performed on specimens of the clay and indicate effective stress parameters of c′=100 psf
and f′=27°. Assume that only the upper 5 ft (1.5 m) of the pile deflects sufficiently to develop
passive pressure. Determine the passive resistance of this upper 5 ft (1.5 m) of soil for both the
short-term and long-term conditions. For the long-term condition, assume the groundwater table
is at the ground surface and neglect possible creep of the soil around the pile.
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