Cyclic Multi-Directional Response of Clay Deposits: Evaluating a Constitutive Model

Abstract

© 2018 American Society of Civil Engineers. The focus of this study is to verify the capabilities of a constitutive model to mimic a wide range of monotonic and cyclic multi-directional stress paths in clays. The generalized elasto-plastic constitutive formulation of the model enables to describe stress-strain response, accumulation of permanent deformations, and excess pore pressure in monotonic and multi-directional cyclic loading. The model is calibrated based on the experimental database on the Gulf of Mexico clay developed at Texas A&M, including the constant rate strain (CRS) consolidation as well as monotonic triaxial tests. Capabilities of the calibrated model to predict the cyclic multi-directional stress paths are then evaluated through comparison with the results of cyclic, circular, and figure 8 multi-directional simple shear tests as a part of the Gulf of Mexico clay experimental database. We also used the extensive database for Boston blue clay (BBC) to calibrate model constants and verify its capabilities to mimic the monotonic and cyclic response of lower plasticity clays. The model proves successful to predict a wide range of complicated cyclic multi-directional stress paths for clays.