Pile response to earthquake loading and soil-pile interaction behaviou
r were investigated experimentally using the hydraulic gradient simili
tude technique. The unique feature of this method is the application o
f a very high hydraulic gradient to increase the effective stresses in
the model, simulating full-scale stress conditions in the field. The
dynamic loading was applied to model piles using a conventional shake
table. Tests on model piles embedded in dense sands are described here
in. Both free vibration and forced vibration simulating earthquake loa
ding were carried out. Pile bending moment, deflection, and accelerati
on were measured during testing. Dynamic p-y curves were derived from
the measurements and were found to be highly nonlinear and hysteretic
at shallow depths under strong shaking. The p-y curves for low-level s
haking showed essentially linear elastic behaviour. The experimental p
-y curves were compared with the backbone p-y curves for sand recommen
ded by the American Petroleum Institute, and the agreement was reasona
ble except at shallow depths.