Abstract: The dynamic properties of frozen clay are studied by hysteresis curves. The test results show that when the temperature of frozen clay is -0.5 ℃- -4 ℃ and the vibration frequency is 1-10 Hz, the stiffness increases, but the viscosity, degree of microscopic damage, residual strain and energy dissipation decreases with the decreasing temperature and increasing vibration frequency. There is no apparent change in the dynamic properties due to the stability of the mechanical properties of frozen clay while the soil temperatures are less than -4 ℃ and the vibration frequencies are greater than 10 Hz. With the increasing dynamic stress amplitude, the stiffness decreases; but the viscosity, degree of microscopic damage, residual strain and energy dissipation increases gradually. With the same dynamic stress amplitude, the influence degree of temperature, vibration frequency and confining pressure on the dynamic properties of frozen clay is maximum, middle and minimum. The degree of microscopic damage and residual strain are affected by temperature, vibration frequency and confining pressure apparently. The viscosity and energy dissipation are affected secondly, and the stiffness is impacted minimally.

Key words: frozen clay, hysteresis curves, stiffness, viscosity, degree of microscopic damage, energy dissipation