低含水率非饱和高温冻土模型

在低含水率非饱和土模型的基础上，从冻土物理特性出发，只考虑毛细吸力和附加压力的作用，建立了非饱和高温冻土细观结构模型，并结合相关实验数据资料改进了高温冻土未冻水含量的经验关系式，基此推导出孔隙水压力、有效应力以及抗剪强度随温度、含水量的变化关系. 同时，通过理论计算与实验（实测）结果进行对比分析，发现本模型能够很好地反映非饱和高温冻土的相关物理力学特性，尤其在定性上能够与宏观实测结果相吻合. 最后，基于非饱和高温冻土微观模型，对非饱和高温冻土的有效应力、抗剪强度进行了讨论分析，给出了合理的理论解释，并对高温冻土相关物理力学特性做出了定性的理论预测.

A model of unsaturated warm frozen soil with low water content

Based on the model of unsaturated soil with low water content and the physical properties of frozen soil, a microstructure model for warm frozen soil with low water content is developed, in which only the effects of additional internal pressure and capillary suction are taken into account. An empirical formula for unfrozen water content of warm frozen soil is improved based on many relevant experiment data. Through these efforts, the relations among temperature, water content and the pore water pressure are gained. The shear strength for the unsaturated warm frozen soil with low water content is also obtained. Through a comparison between the theoretical calculations and experiment results, it is found that the model could well describe qualitatively the physical properties of warm frozen soil. At last, this theoretical model is used to discuss and analyze the effective stress and shear strength of unsaturated warm frozen soil, which not only give a reasonable theoretical explanation, but also predict the physical properties of warm frozen soil qualitatively.