Constitutive model for rate-independent behavior of saturated frozen soils

The mechanical behavior of frozen soils is strongly affected by the amount of ice. The amount of ice depends on the temperature and the applied mechanical stresses. The influence of ice content and temperature on the mechanical behavior and the coupling effects on the reverse direction can be mentioned as the main difference between frozen and unfrozen soils. In the light of this difference, an elastoplastic constitutive model for describing the stress-strain behavior of saturated frozen soils is proposed. By dividing the total stress into fluid pressure and solid phase stress, in addition to consideration of the cryogenic suction, the model is formulated within the framework of two-stress state variables. The proposed model is able to represent many of the fundamental features of the behavior of frozen soils, such as ice segregation phenomenon and strength weakening due to pressure melting. In the unfrozen state the model becomes a conventional critical state model. Typical predictions of the model for simulating the characteristic trends of the frozen soil behavior is described qualitatively. Model predictions are also compared with the available test results and reasonable agreement is achieved. Key words: frozen soil, elastoplastic model, cryogenic suction, solid-phase stress. Le comportement mecanique des sols geles est fortement affecte par la quantite de glace. La quantite de glace depend de la temperature et des contraintes mecaniques appliquees. L'influence de la teneur en glace et de la temperature sur le comportement mecanique et les effets de couplage sur le sens inverse peut etre mentionnee comme la principale difference entre les sols geles et non geles. A la lumiere de cette difference, un modele constitutif elastoplastique est propose pour decrire le comportement de contrainte-deformation des sols geles satures est propose. En divisant la contrainte totale en pression du fluide et en contrainte de phase solide, en plus de l'examen de la succion cryogenique, le modele est elabore dans le cadre des variables d'etat de deux contraintes. Le modele propose est en mesure de representer beaucoup de caracteristiques fondamentales du comportement des sols geles comme le phenomene de segregation de glace et l'affaiblissement de la force du fi la pression de fusion. En etat non gele, le modele devient un modele conventionnel de l'etat critique. Les predictions typiques du modele pour simuler l'evolution caracteristique du comportement de sol gele est decrit qualitativement. Les predictions du modele sont egalement comparees avec les resultats des tests disponibles et un accord raisonnable est atteint. [Traduit par la Redaction] Mots-cles : sol gele, modele elastoplastique, succion cryogenique, contrainte de la phase solide.
Introduction The constitutive modeling of frozen soils has been closely linked with identifying the relevant stress measurements describing the stress-strain behavior. Total stress-based models have been widely used in the [...]