Mechanical behavior and constitutive relation of the interface between warm frozen silt and cemented soil

To study the shear mechanical properties and deformation mechanism of the interface between cemented soil and warm frozen soil, the key parameters are provided for the design and evaluation of cemented soil structure in warm frozen soil ground. In this study, a series of negative temperature direct shear tests of the cast-in-place cemented soil-frozen soil interface were conducted under the influence of different factors. The binary medium model was used to investigate the mechanical stress and deformational mechanisms of the interface, and the damage rate and stress sharing rate functions were introduced. Assuming that the strength of each element of the interface obeyed the Weibull probability distribution, the constitutive equation of the warm frozen soil-cemented soil interface was established. The results showed that the stress-displacement curve of the interface was a strain-softening type, and the entire deformation process of the interface was divided into four stages: the linear elastic, elastic-plastic, softening, and residual stability stages. The constitutive model based on the binary medium theory revealed the micro stress-strain mechanism of the interface and better described the entire stress-displacement process of the interface and the strain softening phenomenon, which can provide a basis for the numerical simulation and theoretical calculation of the structure in the frozen soil ground.