Dynamic parameters of lime-improved saline soil under freeze-thaw and different temperatures

In order to study the stability of lime-improved saline soil roadbed in seasonal freezing areas, laboratory tests are conducted to analyze the change of the dynamic parameters under freeze-thaw and low-temperature environments. The British GDS dynamic triaxial test system (GDSTAS) is adopted to measure the dynamic shear modulus and damping ratio of lime-improved saline soil under different dynamic load frequencies, confining pressures, temperatures and numbers of freeze-thaw cycles. The results show that the dynamic shear modulus at the turning point can reflect the changing trend of the dynamic shear modulus of the sample. The decrease in temperature, the increase in frequency and the increase in confining pressure can increase the dynamic shear modulus and decrease the damping ratio of the sample. The temperature has a more significant impact on the dynamic characteristics. When the number of freeze-thaw cycles increases, the dynamic shear modulus and the damping ratio increase. The temperature correction coefficient and freeze-thaw correction coefficient are proposed to correct the dynamic shear modulus and damping ratio, and the curve fitting is performed. The fitting curve shows that the turning points of the correction coefficient are at -6℃ and the three freeze-thaw cycles respectively. On this basis, a dynamic parameter prediction model is proposed as reference for the stability design of lime-improved saline soil roadbed.