吉林建筑大学学报

以典型季冻区的非饱和粉质黏土为研究对象，利用核磁共振试验系统及GDS非饱和土三轴测试系统，在不同温度条件下，考虑未冻水含量的变化，对不同初始基质吸力土样强度特性进行试验研究。研究结果表明：同一初始基质吸力条件下，随温度的降低未冻水含量下降，同一温度条件下，随基质吸力的增加未冻水含量降低。非饱和冻土在冻结过程中体积未冻水含量的变化可分为过冷阶段（0～-1℃）、快速冻结阶段（-1～-7℃）、稳定冻结阶段（-7～-17℃）。随着温度的降低，不同基质吸力土样的总黏聚力均随未冻水含量的降低呈折线形增大。温度高于-5℃时，随基质吸力的增加，总黏聚力变化与未冻水含量呈反比；温度低于-10℃时，随基质吸力的增加，总黏聚力变化与未冻水含量呈正比。随温度的降低，基质吸力为100 kPa、200 kPa时，有效内摩擦角随未冻水含量的增加而增加。温度一定时，随基质吸力的增加，有效内摩擦角随未冻水含量增大呈先减后增趋势。

Taken unsaturated silty clay in typical seasonal freezing areas as the research object, used nuclear magnetic resonance testing system and GDS unsaturated soil triaxial testing system, the strength characteristics of soil samples with different initial matric suction were experimentally studied under different temperature conditions, considering the changes in unfrozen water content. The research results indicate that under the same initial matric suction conditions,the unfrozen water content decreases with decreasing temperature, and under the same temperature conditions, the unfrozen water content decreases with increasing matric suction. The changes in volume unfrozen water content of unsaturated frozen soil during the freezing process can be divided into supercooling stage(0～-1 ℃), rapid freezing stage(-1～-7 ℃), and stable freezing stage(-7～-17 ℃). As the temperature decreases, the total cohesion of soil samples with different matric suction increases in a linear pattern with the decrease of unfrozen water content. When the temperature is above-5 ℃, the total cohesion changes inversely with the unfrozen water content as the matric suction increases. When the temperature is below-10 ℃, the change in total cohesion is proportional to the unfrozen water content as the matric suction increases. As the temperature decreases, the effective internal friction angle increases with the increase of unfrozen water content when the matric suction is 100 kPa and 200 kPa. When the temperature is constant, with the increase of matric suction, the effective internal friction angle shows a trend of first decreasing and then increasing with the increase of unfrozen water content.