颗粒尺寸对土壤冻胀特性影响的实验研究

Experimental Study on the Influence of Particle Size on Soil Frost Heave Characteristics

本文搭建了可用于土壤冻胀特性研究的实验台,以石英粉为样品,针对三种不同颗粒尺寸(25μm、12.5μm和6.25μm)及一种级配(80%-25μm、10%-12.5μm和10%-6.25μm)的饱和土样,进行了冻胀特性的实验研究。结果表明,土样冻结后存在一个收缩阶段;较小颗粒土样在快速冻结阶段有更高的冻结速率并最终达到更大的冻胀量;级配土样相较25μm土样,快速冻结阶段冻结速率和最终冻胀量都明显增加;浅层土样的快速冻结引起温度的向上波动并向深处传播;12.5μm、6.25μm和级配土样在土样高度13 cm附近形成可视层状冰透镜.

In this paper,an experimental platform was established to study the frost heave characteristics of soil.Taking quartz powder as the sample,four saturated soil samples including three particle sizes(25μm,12.5μm and 6.25μm)and one gradation(80%-25μm,10%-12.5μm and10%-6.25μm)were studied.The results show that there is a shrinkage stage after the soil sample begins to freeze;the soil sample of smaller particle has a higher freezing rate in the fast freezing stage and finally achieves a larger frost heave amount;the freezing rate in the fast freezing stage and the final frost heave amount of the graded soil sample increase obviously compared with the 25μm soil sample;the fast freezing of shallow soil causes an upward fluctuation of temperature and then the fluctuation spreads to the depth;the soil samples of 12.5μm,6.25μm and gradation form visible layered ice lenses near the sample height of 13 cm.