冻结中的固液相变过程是冻土冻胀研究的一个基础.根据热传导理论,对半无限土体的热传导模型进行分析,将冻土分为已冻土和未冻土两个区,对固液相变以及冻结锋面的移动进行研究,探索影响冻土温度分布的因素,研究含水量、干密度和土的类型对温度场及冻结锋面移动速率的作用.同时根据冻结锋面的移动规律,建立了冻胀量随时间的关系式.最后,通过算例,结果表明含水量和干密度对冻土温度分布产生不小的影响,尤其是含水量,含水量越大,冻结锋面移动越快.含水量对冻土温度分布的影响最大,其次是干密度,土类型的影响最小.分析显示冻胀过程中温度与冻胀的影响作用明显,含水量是一重要因素,对冻胀量的影响是非常显著的.
Solid-liquid phase transition is a basis for frost heave of frozen soils.According to frozen soil theory,an infinite mathematical model was developed.The whole domain for frozen soil was divided into two zones: frozen zone and unfrozen zone.The influence of water content,dry density and soil type on the temperature profile and freezing front in one-dimensional problem was analyzed.In terms of freezing front movement,the equation calculating frost heave with time was made.The results from a case study indicate that water content and dry density have an important effect on the temperature profile and freezing front in frozen soils.The higher the moisture is,the more quickly the freezing front moves.The type of soil plays a role in the temperature distribution in frozen soil.The calculation shows that there is a marked relationship between temperature distribution and the frost heave,and that the effect of moisture on frost heave is very marked.