General elastic analysis of piles and pile groups

This paper describes the development of a boundary element analysis for the behaviour of single piles and pile groups subjected to general three-dimen sional loading and to vertical and lateral ground movements. Each pile is d iscretized into a series of cylindrical elements, each of which is divided into several subelements. Compatibility of vertical, lateral and rotational movements is imposed in order to obtain the necessary equations for the pi le response. Via hierarchical structures, 12 non-zero sub-matrices in a glo bal matrix are derived for the basic influence factors. Solutions are presented for a series of cases involving single piles and pi le groups. Tn each case, the solutions are compared with those from more si mplified existing pile analyses such as those developed by Randolph and by Poulos. It is shown that for direct loading effects (e.g. the settlement of piles due to vertical loading), the simplified analyses work well. However , for 'off-line' response (such as the lateral movement due to vertical loa ding) the differences are greater, and it is believed that the present anal ysis gives more reliable estimates. Copyright (C) 2000 John Wiley & Sons, L td.