Soil–pile–structure interaction simulations in liquefiable soils via dynamic macroelements: Formulation and validation

Abstract

We present a macroelement for soil–structure interaction analyses of piles in liquefiable soils, which captures efficiently the fundamental mechanisms of saturated granular soil behavior. The mechanical model comprises a nonlinear Winkler-type model that accounts for soil resistance acting along the circumference of the pile, and a coupled viscous damper that simulates changes in radiation damping with increasing material nonlinearity. The formulation for a gap element is also proposed to account for formation of gap at pile–soil interface. Validation of the macroelement is conducted using full-scale forced vibration test data from a blast-induced liquefaction test bed, and centrifuge data for seismic loading of piles with superstructure. The macroelement parameters are estimated as a function of the measured soil properties and the level of effective stress. Predictions of bending moments and acceleration time histories at the top of pile and the superstructure are found to be in good agreement with both the full and the model scale data. A comparison with predictions from alternative established methodologies is also presented.