Verification of bounding surface plasticity model with reversal surfaces for the analysis of liquefaction problems

Abstract

This paper presents the verification of a new bounding surface plasticity model with reversal surfaces when used in boundary value problems related to liquefaction. The model is implemented in a commercial finite-difference code using an explicit stress integration algorithm. After validating the model against element tests on Nevada sand, the paper employs the same set of values of model parameters for ascertaining the model's simulative potential at the system level, via comparisons with data from 8 dynamic centrifuge tests performed on the same sand. These pertain to: a) the free-field response of a horizontal liquefiable layer, b) the lateral spreading response of a gently sloping liquefiable layer and c) the seismic response of rigid foundations on a single-layered and two-layered horizontal liquefiable ground profiles. Parametric analyses emphasize the effects of non-constant sand permeability coefficient and excitation intensity on the liquefied system response. Similar analyses highlight the importance of post-liquefaction strain accumulation and the avoidance of stress-strain overshooting, both constitutive attributes of the new model.