Modified Elastic Parameters for the Dynamic Axial Impedance of Driven Piles

Abstract

Experimental investigations reported in the literature have shown that pile foundations exhibit nonlinear behavior when subject to dynamic axial service loads. The nonlinear characteristics are attributed to soil remolding, soil nonlinearity, and pile–soil separation/slippage. The traditional methodology for computing the nonlinear dynamic response of pile foundations requires the estimation of upward of six parameters pertaining to an inner annular region of weakened soil. This article presents a simplified approach to account for such nonlinear behavior of driven piles by introducing shear-moduli modification factors within the traditional elastic model. The proposed methodology, termed the modified elastic model, is computationally simpler than the traditional nonlinear model and requires significantly fewer parameter estimates. The modified elastic model is validated with nine experimental response curves originating from three test configurations.