【摘要】 <正> 温度、水分(包括冰与未冻水)及结构状况直接影响着冻土的各种性质。一定负温下,不但冻土中冰晶含量取决于含水量,而且随土粒径的不同,含水量变化也必将或多或少地影响到冻土的结构状况。改变含水量,冻土的物理力学性质随之改变,同时它的声学特性也将发生相应变化。了解冻土中声波传播速度的变化规律,对于研究冻土物理力学性质以及用声测法对冻土进行无损检测,无疑具有重要意义。更多还原

【Abstract】 When ultrasonic wave propagates in frozen soils, its velocity will change with the moisture content of the soils.In coarsegrained frozen soils, ultrasonic velocity increases unlinearly with the increase in moisture content and density. However in fine-grained frozen soils, it varies irregularly with moisture and increases unlinearly with the decrease in density.In this paper, the influence of soil temperature on the variation of ultrasonic velocity is analysed, and the changes in the structure of frozen soils are also analysed on basis of the variation of the velocity with the unfrozen water content in frozen soils.The variation of ultrasonic velocity can well reflect the changes in some mechanical parameters of frozen soils, such as dynamic elastic modulus, poisson ratio, etc. These are also expounded in the paper.更多还原