Pile Group Settlement Estimation: Suitability of Nonlinear Interaction Factors

Abstract

In this paper, predictions of pile settlement determined by appropriate superposition of two-pile interaction factors are compared with those computed from continuum analysis. A finite-element package is used in conjunction with the nonlinear Hardening Soil model and the pile group sizes studied are larger than in previous research. The study is presented in two phases: (1) examination of the modulus variation within the group allowing the elimination of some variables, and (2) comparison of pile settlement predictions in the context of the significant variables. The research shows that predictions using the former approach match the continuum analyses very closely for friction piles and reasonably well for end-bearing piles, and show potential for reducing computational time and effort in such problems. The paper also distinguishes between alternative definitions of interaction factor and shows that most accurate predictions arise from interaction factors calculated when only one of the two piles is loaded.