冻融循环作用下寒冷地区铁路路基泡沫轻质土填料性能衰减规律

通过冻融循环试验和无侧限单轴抗压试验，以水固比、泡沫溶液质量分数、冻融循环次数为控制因素，分析泡沫轻质土物理力学性能衰减规律。结果表明:冻融循环6次前的冻融劣化效应显著，12次之后土体结构趋于稳定；泡沫掺入量为10.0 %、水固比1∶1.2时试样的最终强度损失率为24.1 %，而泡沫掺入量为6.0 %、水固比1∶1.8时的强度损失率仅为6.3 %。冻融循环试验后的土样力学强度满足铁路基床应力环境要求，可为泡沫轻质土在寒区路基的应用提供参考。

Attenuation Law of Performance of Foam Light Soil Fillers for Railway Subgrade under Freeze-thaw Cycles in Cold Regions

Based on freezing-thawing cycle test and unconfined uniaxial compression test, water solid ratio, mass fraction of foam solution and the number of freezing-thawing cycles were taken as control factors to analyze the attenuation law of the physical and mechanical properties of foamed light soil. The results show that the freezing and thawing deterioration effect is significant before 6 cycles of freezing and thawing. The soil structure tends to be stable after the 12th freezing-thawing cycle. The final strength loss rate is 24.1 % when the foam content is 10.0 % and the water-solid ratio is 1:1.2, while the strength loss rate is only 6.3 % when the foam content is 6.0 % and the water-solid ratio is 1:1.8. The mechanical strength of soil samples after freezing-thawing cycle test meets the stress environment requirements of railway foundation bed, which can provide reference for the application of foam light soil in cold regions.