Estimating the elastic settlement of piled foundations on rock

Abstract

This research introduces a simple method for preliminary evaluation of the elastic settlement of piled foundations resting on rock. Despite a significant number of publications in this area, the present effort is distinguished by adopting a unique representation of rock nonhomogeneity. It also considers pile-subgrade stiffness ratios that have not been covered in the literature for piled foundations on nonhomogeneous media. The settlement behavior was investigated using an extensive three-dimensional finite-element (FE) analysis of different piled foundation models. Elastic settlement of single piles was also studied for comparison with the pile-group behavior. Charts were developed to estimate the elastic settlement of piled foundations and to help in choosing the optimum pile spacing and length that limit foundation settlement to tolerable levels. Settlement values yielded from the FE analysis were compared with those calculated from equations commonly used in estimating elastic settlement of foundations.