Freeze–thaw (FT) cycles induce microcracks within soils altering their strength and deformation properties. Previous studies have primarily focused on strength degradation, while much less attention has been given to deformation, particularly post-peak strain-softening behavior. This study introduces a hyperbolic decay model to characterize FT-induced strength deterioration. In addition, a novel stress–strain model extending the disturbance state concept (DSC) is developed for FT-impacted soils, with particular emphasis on post-peak strain-softening behavior. In this DSC framework, a hyperbolic hardening response is defined as the relative intact (RI) state, and the critical state as the fully adjusted (FA) state. The stress–strain response of FT-impacted soils is then described by coupling the RI and FA states through a disturbance function (D). The proposed model incorporates five mechanically meaningful parameters, for which both the determination procedures and predictive relationships are established. Model validation using experimental data for four soil types (fat clay, lean clay, silty sand, cemented soil) demonstrates strong agreement between predicted and measured responses. Furthermore, comparisons with several existing constitutive models, including the double hardening model, the elastoplastic model, the binary-medium model and the fractional order model, indicate that the developed DSC model provides a consistent and reliable representation of FT-impacted soil behavior.
Zhang et al. (Tue,) studied this question.