Influence of pre-seismic history on liquefaction resistance of seasonal frozen sand

Field investigation revealed that soil liquefaction occurred in seasonal freezing regions, which was frequently associated with earthquakes. Most previous studies focused on the effects of freeze-thaw cycles on the cyclic response of seasonal freezing soil, little attention has been given to the influence of pre-seismic history on soil liquefaction resistance. Therefore, a series of element tests were conducted on sand to explore the combined impact of freeze-thaw cycles and pre-seismic history. The test results showed that both the frost heaving ratio and thaw settlement coefficient initially increased and then stabilized after the 4th freeze-thaw cycle. The sand’s liquefaction resistance was found to improve with a small pre-seismic history (upre≤0.2), but gradually decreased with upre≥0.4. Notably, the sand exhibited the highest strength at approximately 1.3 times that of the original sample, while showing the weakest resistance at only 0.33 times that of the original. Furthermore, when sand underwent both freeze-thaw cycles and pre-seismic history, only 15% of samples showed increased resistance. These findings suggest that the influence of freeze-thaw cycles on sand liquefaction was more pronounced than the impact of pre-seismic history.