Study on Characteristics of Hydro-Thermal Transfer andFreezing-Thawing of Soil-Rock Mixtures

The rock content in freezing-thawing cycles is one of the key factors influencing the hydro-thermal transfer and freezing-thaw transferring characteristics of soil-rock mixtures. To study the effect of freezing-thawing cycles on hydro-thermal transfer, frost heave and thawing settlement of soil-rock mixtures, the soil-rock mixtures composed by Qinghai-Tibet silty clay and gravel with different stone content ratios (10%, 25%, 40%) were selected as research objects, and 10 unidirectional freezing-thawing cycles were conducted. The results indicated that the differences in the temperature and unfrozen water content of soil-rock mixtures during the freezing-thaw cycles had a strong correlation with the rock content. With an increase in the rock content, the completely frozen time for soil-rock mixtures has been extended, and the variable rate of the unfrozen wate content decreased. The difference of buried depth mainly influenced the temperature transfer of soil-rock mixture, and had an indirect effect on the variation of volumetric unfrozen water. For the samples with stone contents of 10% and 40%, the displacement change was manifested as shrinkage during freezing and expansion after thawing, and with an increase in the stone content, the shrinkage of specimens during freezing tended to decrease.