VERTICALLY LOADED PILES IN NONHOMOGENEOUS MEDIA

Analytical methods for the axial responses of piles can be classified under three broad categories of (1) simple but approximate analytical solutions, (2) one-dimensional numerical algorithms, (3) full axisymme tric analyses using boundary or finite element approaches. The first t wo categories rely on the so-called load transfer approach, with inter action between pile and soil determined by independent springs distrib uted along the pile shaft and at the pile base. The non-linear spring stiffness is related to the elastic-plastic properties of the actual s oil partly by empirically based correlations and partly by theoretical arguments based on simplified models of the pile-soil system. This pa per presents new closed-form solutions for the axial response of piles in elastic-plastic, non-homogeneous, media, The solutions fail in the first of the three categories above, and have been verified through e xtensive parametric studies using more rigorous one-dimensional and co ntinuum analyses. The effect of non-homogeneity and partial slip on th e load and displacement profiles along the pile shaft is explored, and comparisons are presented with experimental data. (C) 1997 by John Wi ley & Sons, Ltd.