Comparison of Anisotropic Rate-Dependent Models for Modeling Consolidation of Soft Clays

Two recently proposed anisotropic rate-dependent models are used to simulate the consolidation behavior of two soft natural clays: Murro clay and Haarajoki clay. The rate-dependent constitutive models include the EVP-SCLAY1 model and the anisotropic creep model (ACM). The two models are identical in the way the initial anisotropy and the evolution of anisotropy are simulated, but differ in the way the rate effects are taken into consideration. The models are compared first at the element level against laboratory data and then at the boundary value level against measured field data from instrumented embankments on Murro and Haarajoki clays. The numerical simulations suggest that at the element level, the EVP-SCLAY1 model is able to give a better representation of the clay response under oedometric loading than ACM, when the input parameters are defined objectively. However, at the boundary value level, the issue is not as straightforward, and the appropriateness of the constitutive model may depend heavily on the in situ overconsolidation ratio (OCR). (C) 2014 American Society of Civil Engineers.