Testing and Characterization of the Freeze–Thawing Effect on the Morphology of Quartz Sand

Abstract This research aimed to investigate the morphological changes of sandy soils with a varying number of freeze–thaw cycles (FTCs). The primary objective was to characterize the changes in particle morphology and establish the relationship between the number of FTCs and these changes. Two variables, namely the amount of variation and the coefficient of variation, were introduced as parameters to characterize the morphological changes of sandy soils. Statistical analysis was performed using the PIP9.1 particle dynamic image analyzer to quantify the morphological characteristics of sandy soil particles. The results showed that the five morphological characteristic parameters of sandy soil particles conformed to a normal distribution. The particle shape was primarily blocky, and sandy soil particles appeared more broken and regular in shape with an increase in the number of FTCs. The coefficients of variation of particle filling exhibit “conjugate” changes with other indicators, and the coefficients of variation of each indicator decrease gradually with an increase in the number of FTCs. Principal component analysis was employed to integrate information on sandy soil particle shape, resulting in a new index that established the relationship between the index and the number of FTCs. The findings of this study provide a better understanding of the morphological changes in sandy soils under freeze–thaw conditions and offer insight into the stability of sandy soils under these conditions.