高温冻土物理力学特性研究现状

高温冻土又称近相变区冻土, 通常用来描述相对较高温度的冻土. 由于其温度区间处于冻土的剧烈相变区, 冻土中冰和未冻水的比例对温度的变化极其敏感, 因此, 高温冻土的物理力学性质具有强烈的不稳定性, 极易在温度变化的影响下发生实质性改变. 基于有关高温冻土物理力学性质研究的文献, 综述了高温冻土的定义及其温度界限, 同时论述了未冻水对高温冻土物理力学性质的巨大影响, 并提出了一种在冻结状态下高温冻土中未冻水孔隙水压力的测试方法. 重点从强度特征、变形特性以及本构模型三方面对高温冻土力学特性的研究现状进行了总结和分析, 并提出要进一步探究高温冻土变形机理及本构模型, 可以为高温不稳定多年冻土区各类工程的基础变形及稳定性预报、评价提供理论基础.

Review on Physic-Mechanical Properties of Warm Frozen Soil

Warm frozen soil refers to the frozen soil in the temperature range with severe phase changes.The term of warm frozen soil is usually used for describing frozen soil in relatively higher temperature blow 0 ℃.As a result of the temperature range with severe phase changes,the proportion of ice to unfrozen water is extremely sensitive to temperature change.Therefore,warm frozen soil is prone to considerable variation in physic-mechanical properties.Based on documents on physic-mechanical properties of warm frozen soil,the definition and temperature boundary of warm frozen soil are reviewed in this paper.It is revealed that unfrozen water has a tremendous impact on the physic-mechanical properties of warm frozen soil,and pointed out that to measure the pore water pressure in the warm frozen soil is meaningful and interesting.The general findings of recent researches are reviews in this paper.The mechanical properties of warm frozen soil are summarized from three different respects,including strength characteristics,deformation properties and constitutive models.In order to provide theoretical basis for analysis of deformation and stability of foundations for various engineering projects in warm permafrost regions,further researches on the mechanism of deformation and proper constitutive model of warm frozen soil is around the corner.