高含冰(水)量冻土的单轴抗压强度变化特性研究

Study of the uniaxial compressive strength characteristics of frozen soil with high ice/water content

沿用已有的制样方法,在统一了制样过程中冰、水比例及冰颗粒尺寸的基础上,开展了高含冰(水)量粉质砂土的单轴抗压强度系统性测试.结果表明:高含冰(水)量冻土的单轴抗压强度随应变率的增加而非线性增大;随温度升高而减小,减小趋势与总含水量有关.随含水量的增加,强度先是非线性增大,然后逐渐趋于重塑冰的强度,这有别于早期类似研究的结果.同时,也对试样中加入冰颗粒以保证试样高含冰(水)量的制备方法合理性产生了质疑.

Silty sand with high ice /water content was tested under uniaxial compression on the basis of the previous method of specimen preparation and unifying the weight ratio of ice to water. It is found that uniaxial compressive strength of frozen silty sand nonlinearly increases with increasing strain rate,but the increasing rate gradually decreases with the increase of strain rate,and the relationship between the uniaxial compressive strength and the strain rate can be described by a log function. In addition,the higher temperature is,the smaller the extent is,in which the strain rate governs the uniaxial compressive strength; the uniaxial compressive strength decreases with raising temperature and the decline＇ s rate gradually decreases with raising water content. With increasing water content,the uniaxial compressive strength begins to increase nonlinearly,and finally approaches to that of strength of remolded ice,which is different from the early research and results in a doubt on the correctness of the method of specimen preparation by means of adding ice particles to guarantee high ice /water content of specimen.