Dynamic constitutive model of saturated saline frozen soil under uniaxial impact loading

Abstract

The soil matrix, salt crystals, ice crystals, and pore solutions constitute the composite geological material of saturated saline frozen soil. The destruction mode and dynamic constitutive model of saturated saline frozen soil need to be studied because infrastructure construction is increasingly being extended to regions with saturated saline frozen soil. Based on the split Hopkinson pressure bar device, uniaxial impact compression tests were conducted on frozen soil samples with different salt contents under different strain rates. The strain rate of saturated saline frozen soil must be emphasized based on the results. The gradient of the elastic segment and maximum stress of the soil are negatively correlated with the salt content increase. To further explore the failure mechanism, the study examined the damage and failure behavior of saturated saline frozen soil, along with the absorption energy in the failure process. According to the test results, the saturated saline frozen soil was similar to a particle-reinforced composite. Subsequently, the debonding damage of the ice–salt eutectic and the mechanical–chemical damage of the soil matrix were considered. The test results could be predicted accurately from the results of the model, verifying that the influences of the salt content and strain rate are reasonably considered by the constructed model.