A poromechanics-based macro-mesoscopic constitutive model for warm frozen soil

This paper presents the establishment of a macro-mesoscopic constitutive model based on poromechanics for investigating the mechanics of warm frozen soil. The elastic parameters of warm frozen soil are influenced by the ice content variations during the loading process, considering the pressure melting characteristic of warm frozen soil. Through the integration of poromechanics and mesomechanics, a macro-mesoscopic constitutive model incorporating the pressure melting effect is developed to characterize the mechanical properties of warm frozen soil. The proposed model establishes a relationship between the elastic modulus at the mesoscopic and macroscopic scales of warm frozen soil.To validate the model, a comparison is made between the model predictions and experimental data obtained from warm frozen silt. The results demonstrate that the model effectively captures significant mechanical performance of warm frozen soil, including strain soft and dilatancy phenomena under various confining pressure conditions. Furthermore, the proposed model enables the prediction of freezing temperature variations, unfrozen water saturation, unfrozen water pressure, ice pressure, and porosity changes in warm frozen silt samples during the loading process.