含氯化钠冻土未冻水含量与冻融过程关系的特征

Unfrozen Water Content of Soil Containing Nacl Relating to Freezing-Thawing Processes

在对不同总含水量和土中溶液初始浓度的含氯化钠冻土冻融两个过程中未冻水含量测定的基础上，发现对于含氯化钠的冻土，其融化过程中未冻水含量随温度的变化同冻结过程相比，具有一定的滞后性。在二次相变发生之前的第一段曲线，滞后的差值随温度降低呈指数形式减小，随总含水量和初始土中溶液浓度增大而线性增大。由于冻融过程中二次相变点有所不同，因此在某一温度范围内，融化过程未冻水含量的滞后值很大，且随总含水量和初始土中溶液浓度的增大而增大，并随土类不同而不同。

The general relation between the unfrozen water content and temperature is various be-cause of appearence of second phase transition of NaCl solution in the soil．This paper pres-ents the difference of unfrozen water contents during freezing and thawing．It is found thatunfrozen water content in thawing is less than that in freezing． The points of second phasetransition of the NaCl solution in soil are different in the two processes.