An elasto-plastic constitutive model for frozen soil subjected to cyclic loading

Abstract Upon employing the theoretical frame of breakage mechanics for geological materials and homogenization, a new elasto-plastic constitutive model is proposed to investigate the dynamic mechanical behaviors and volumetric strain of frozen soil under cyclic loading. In this model, using a mesoscopic method to formulate the breakage of frozen soil by idealizing it as a binary medium, assuming respectively the unbroken state as bonded element and the damage state as frictional element. During the loading process, the evolution of the nonuniform deformation and ice cementation breakage is described by the local strain concentration coefficient and breakage ratio, respectively. The dynamic triaxial compression test data for different confining pressures, coarse particle contents, and dynamic deviatoric stress amplitudes are utilized to confirm the suitability of the new elasto-plastic constitutive model. In the results, the model presented the stress-strain curves and volumetric strain curves of frozen soil under cyclic loading which captured the basic dynamic characteristics, such as nonlinear variation, hysteresis behaviors, and plastic strain accumulation behaviors. Herein, the extensive experimental validation shows the applicability of the proposed model.