Dynamic Characteristics of Freezing-Thawing Aeolian Soil under Intermittent Cyclic Loading

To investigate the dynamic characteristics of the soil in seasonally frozen areas under intermittent cyclic loading, a series of dynamic triaxial tests on frozen-thawed aeolian soil were conducted by using the global digital system dynamic triaxial apparatus (GDS-DYNTTS). The dynamic elastic modulus and the dynamic damping ratio of freeze-thaw aeolian soil under different effective consolidation confining pressures, freeze-thaw cycles, dynamic stress amplitudes, and vibration frequencies were investigated. The results demonstrated a "step-type" dynamic elastic modulus curve for freeze-thaw aeolian soil under intermittent cyclic loading, and higher values were found compared to when the soil was under continuous vibration load. The developmental trend of the dynamic damping ratio was divided into accelerated growth and stable stages. The dynamic damping ratio under the intermittent condition was lower than that under continuous vibration load, which indicated that the intermittent stage reduced the internal energy consumption of soil samples and provided an improved buffering capacity against the vibration load. Overall, the fractional-order mathematical model based on the time-hardening approach exhibited good prediction skills for the freezing-thawing aeolian soil dynamic elastic modulus under intermittent cyclic loading. The results of this study will provide beneficial guidelines for engineering construction and disaster prevention practices in areas with seasonally frozen soils.