中文摘要：

通过室内大尺寸非饱和黄土冻结作用下水分迁移试验，开展了土体密度、含水量、冻结温度、冻结方式对非饱和黄土水分迁移影响的研究。试验结果表明：冻结过程中土样温度变化分为3个阶段：急剧降温阶段，缓慢降温阶段，稳定阶段；干密度越大，稳定冻结锋面的水分迁移量越大，但冻结区的整体水分增量越小；初始含水量越大，水分迁移量越大，并且在冻结锋面处含水量增幅越大；在未冻结区，从邻近冻结锋面到暖端，含水量先增大后减小，初始含水量越小，这种现象越明显。此现象是冻结界面抽吸力、温度梯度和基质吸力梯度共同作用的结果。冻结方式直接影响已冻结区的含水量分布和水分迁移总量。

英文摘要：

This paper carries the moisture migration tests of unsaturated loess with the large size sample under freezing effect.It examines the influence of density,water content,freezing temperatures and freezing way on moisture migration of unsaturated loess.Results show that the soil sample temperature change under freezing process is divided into three stages:rapid cooling stage,the slow cooling stage,and stable stage.For higher dry density, the increase of water content at the frozen front is greater,but the increase of water migration of moving to the frozen part is lower.For a certain dry density,if the initial water content is higher,the amount of moisture migration is greater.And the increase of water content of the frozen front is also the greater.From the cold end to the warm end in the unfrozen area,water content increases at first,then decreases.And,this phenomenon is the more evident with lower initial water content.This phenomenon is the combined effect of the freezing interface suction force, temperature gradient and the matric suction gradient.The water content distribution and the total amount of moisture migration in frozen area are affected directly by the freezing way.