Settlement of Single Piles in Nonhomogeneous Soil

An analysis, previously developed for evaluating the settlement of a pile in homogeneous soil, is extended to the case of nonhomogeneous soils. Comparisons with finite element solutions suggest that the analysis gives solutions of adequate accuracy for practical purposes. A series of parametric solutions is presented for a pile in a Gibson soil in which the modulus increases linearly with depth. The analysis is also found to be applicable to piles in a layered soil, except in the case where the pile is founded in soil that is more compressible than the overlaying strata. A simple approximate method is described for using the available solutions for uniform soils to calculate the settlement of piles in nonhomogeneous soils. The determination of soil modulus values is then examined briefly, and finally, some comparisons between measured and theoretical pile behavior are presented to indicate the possible practical consequences of assuming a soil profile to be nonhomogeneous rather than homogeneous.