D. Badoni et N. Makris, PILE-TO-PILE INTERACTION IN THE TIME-DOMAIN NONLINEAR AXIAL GROUP RESPONSE UNDER HARMONIC LOADING, Geotechnique, 47(2), 1997, pp. 299-317
An approximate, physically motivated procedure to compute the non-line
ar axial response of single piles and pile groups under harmonic loadi
ng is presented. The method utilizes a non-linear shaft model in conju
nction with a time domain formulation for the propagation of waves emi
tted from the periphery of each pile, to account for pile-to-pile inte
raction. The shaft model involves standard geotechnical parameters. Yi
elding of the soil surrounding the pile and slippage along the pile-so
il interface are modelled separately. The model is calibrated using da
ta from well-instrumented full-scale experiments, Hysteretic damping i
s modelled through non-linear distributed springs governed by the Bouc
-Wen model, whereas radiation damping is approximated with frequency-d
ependent distributed dashpots. It is assumed that non-linear behaviour
is confined to the near vicinity of the pile-soil interface and that
the soil in between piles remains linearly viscoelastic. Plane-strain
theory of wave propagation is utilized and an attenuation function in
the time domain is derived to approximate the influence of motion of o
ne pile on another A qualitative study of non-linear effects on pile-g
roup response is presented. It is observed that nonlinear behaviour su
ppresses pile-to-pile interaction, while reducing the equivalent stiff
ness and increasing equivalent damping.