Analysis of Three‐Dimensional Damage Constitutive Model of Frozen Sand Based on the Influence of Intermediate Principal Stress and Temperature

Abstract

To study the mechanical properties of frozen soil, it is necessary to understand the damage characteristics of frozen soil. Four types of three-dimensional indoor tests of frozen sand were carried out at −5°C, −10°C, and −15°C to study the mechanical damage properties. These include different stress path tests with the principal stress coefficients of 0, 0.25, 0.5, and 0.75 while analyzing the entire failure process. First, the three-dimensional compression test of frozen sand was studied to analyze the influence of temperature and intermediate principal stress coefficient on the large principal stress of frozen soil. The damage cost of frozen sand under the influence of different temperatures and intermediate principal stress coefficients was also established. Second, using the characteristics of discreteness and randomness of the distribution of the microelements inside the frozen soil and assuming that the failure of the microelement of the frozen soil obeys the Weibull distribution, the Drucker–Prager strength criterion was used as the statistical distribution variable of the microelement of the frozen soil based on the strain equivalence hypothesis, statistical theory, and continuous damage mechanics. This allows for a constitutive model of frozen sand damage under the three-dimensional stress state to be established. Finally, the model parameter values through low-temperature three-dimensional test data were able to be determined. This model allows for the physical meaning of Weibull distribution parameters F0 and m to be analyzed, and the distribution parameters with temperature and intermediate principal stress coefficient can be modified to obtain a modified frozen sand damage constitutive model. The results show that the modified damage constitutive model can simulate the entire process curve of the large principal stress-strain of frozen sand. It shows that the large principal stress of frozen sand increases with the increase of temperature and intermediate principal stress coefficient. Concurrently, the frozen sand damage constitutive model proposed in this paper can describe the deformation behavior of frozen soil under different temperature and stress paths and can be adapted to various other sediment types.

Experimental Study on True Triaxial Mechanical Properties of Frozen Calcareous Clay under the Influence of Multiple Factors

“…Zhang et al [25] investigated the stress-strain relationship of soil under different coefficients of intermediate principal stress and different stress path conditions, elucidating the influence of the intermediate principal stress and stress path on the mechanical properties of soil. Previous studies [26,27] have investigated the influence of water content, consolidated confining pressure, the coefficient of intermediate principal stress, and intermediate principal stress ratio on the strength of frozen clay through true triaxial tests. Yang et al [28] conducted a triaxial compression test on frozen silt at different temperatures and different confining pressures and obtained the relationship between the compressive strength of frozen silt, the temperature and confining pressure.…”

Orthogonal Test on the True Triaxial Mechanical Properties of Frozen Calcareous Clay and Analysis of Influencing Factors

“…As reported by Chen [19], when the consolidated confining pressure was less than the structural strength of the structural loess, the stress-strain curve was a softening type; otherwise, it was a hardening type. Ma [20] and Zhang [21] conducted a true triaxial test on frozen sand under the influence of Bishop parameter b and accordingly performed an analysis.…”