Meso-macro constitutive model for frozen salinized sandy soil

Abstract

In the permafrost areas, the frozen salinized sandy soil is a unique geotechnical component whose mechanical properties will influence the stability of engineering. Thus, formulating a constitutive model for frozen salinized sandy soil has significance scientifically for the design of engineering in cold regions. Combining the theoretical framework of breakage mechanicals for materials, micromechanical analysis method, and homogenization method, a meso-macro constitutive model for frozen salinized sandy soil is put forward in this research. In the proposed model, considering the structure characteristics, the frozen salinized sandy soil is abstracted as a type of inhomogeneous binary materials, the bonded elements composed of the unbroken ice crystals, salt crystals, and soil particles, behaving elastic-brittle mechanical properties, and the frictional elements composed of the broken ice crystals, salt crystals, and soil particles, with elastic-plastic mechanical properties. Due to the disparity in the mechanical characteristics of the constituent materials, the impact of salt concentration on the mechanical parameters of the bonded elements is also taken into consideration. Moreover, the nonuniform distribution of stress and strain with the representative volume element is described by introducing the breakage ratio with the derivation of the strain concentration tensor. The comparison with the tested results demonstrates that the proposed mese-mace constitutive model could simulate the stress-strain and volume law of frozen salinized sandy soil under different confining pressures, which has satisfactory adaptability to reflect the physical and mechanical properties of frozen salinized sandy soil.