The modes and its implications of water accumulation near the freezing front during soil freezing with considering ice segregation北大核心CSCD

Water accumulation associated with water migration is closely related with the ice segregation，but their coupling relationship is still unclear. To decoupling the relationship of water accumulation and ice segrega⁃ tion，herein，the dynamics of water migration and ice segregation during the freezing and thawing of different soil types under different water supplying conditions have been investigated based on pore water pressure mea⁃ surement and layer-scanning technique. Results showed that apparent water accumulation near the freezing front during the freezing of silty clay and loess tested here，but there exist differences in modes. During loess freezing under closed system，no ice segregation was observed，the pore water pressure increased，and there existed ap⁃ parent liquid water accumulation during the early stage of freezing；while during the freezing of silty clay，there existed ice segregation，the pore water pressure decreased，and no apparent liquid water accumulation occurred during the early stage of freezing. The results implied that there exist two modes of water accumulation near the freezing front during soil freezing：one is the water accumulation induced by water pressure gradient induced by pore ice which results in water flowing from the frozen zone and unfrozen zone to the location near the freezing front；the other is the water accumulation induced by cryo-suction of segregation ice which results in the water flowing from the unfrozen zone to the location near the freezing front. Notably，the contribution from each mode associated with water accumulation of soil freezing depends on whether the ice segregation exists. As no ice seg⁃ regation forms，water accumulation induced water pressure gradient predominates during the early stage of freez⁃ ing. As there exists ice segregation during freezing，water accumulation induced cryo-suction predominates dur⁃ ing the later stage of freezing. Investigating on different modes of water accumulations will be helpful for the ex⁃ ploring the mechanisms of freeze-thaw diseases and the ground ice in the cold regions. © 2023 Chinese Journal of General Practitioners. All rights reserved.