A BNWF APPROACH TO ASSESS THE RESPONSE OF SINGLE PILE SUBJECTED TO FAR-FIELD AND NEAR-FIELD EARTHQUAKES

Kinematic responses of single fixed-head vertical piles in homogeneous loose sand profile under far-field and near-field ground motions have been studied. For numerical simulation of soil-pile interaction, Beam on Nonlinear Winkler Foundation (BNWF) modelling technique has been adopted. The soil and pile behaviours are represented using nonlinear Winkler springs and beam-column elements, respectively. The Winkler springs are modelled using a series of p–y, t-z and Q-z curves to represent the lateral and axial soil– pile interaction. To obtain the free-field earthquake motions for application at the free ends of the nonlinear p-y springs along the depth of the pile, nonlinear site response analyses have been carried out separately. This study focuses on assessing the impact of ground motion characteristics, longitudinal reinforcement percentages and pile diameter on the nonlinear response of piles. The response of a single pile has been studied considering the minimum and maximum reinforcement criteria recommended by the relevant Indian Codes of Practice. The outcomes of the study are presented in terms of maximum bending moments of the pile, stress-strain histories of the pile material and plastic hinge lengths. © 2024, International Association for Earthquake Engineering. All rights reserved.