季冻区粉砂土路基水、温变化监测与分析

Monitoring and Analysis of Moisture and Temperature of Silty Soil Subgrade in Seasonally Frozen Region

粉砂土介于细砂土和粉土之间,颗粒组成中黏性颗粒含量较少,用其填筑的路基含水率变化范围较大且与路基温度变化有一定的关系,在负温条件下由于水分的迁移积聚会加剧路基的冻胀。为了研究季冻区粉砂土路基的水、温变化规律及其对路基冻胀的影响,选择典型粉砂土路基,利用自主研发的监测设施对试验段路基水、温变化进行监测和分析,结果表明:路基在冻结过程中,水分在温度梯度的作用下,越往路基上层迁移积聚现象越显著;在路基不同深度处,由于温差和含水率的不同冻结单位厚度(即0.2m)土层所需的时间也有所差异;填方路基由于边坡的存在,距边坡较近处路基土的温度要略高于路中线处路基土的温度,冻融所需时间也短于后者。研究结果进一步了解了粉砂土路基的水、温变化规律及冻融过程,对今后粉砂土路基的施工和冻害防治具有一定的参考和借鉴作用。

Silty soil is between fine-sand soil and powder soil,the moisture in the subgrade which filled with silty have a large range,and have a relationship with the changing of humidity of the subgrade in a negative temperature conditions will aggravate the subgrade freezing.In order to understand the changing of soil subgrade＇s temperature and moisture in seasonal frost region,using self-developed monitoring facility consummates the roadbed moisture and temperature data,the results show that： in the freezing process of the roadbed,under the effect of temperature,more to the accumulation of the phenomenon of migration of the upper roadbed,more significant;in different depths of the subgrade.as temperature and water are different,freezing unit thickness（ie 0.2m） of soil is different in the time required;embankment slope exists due,subgrade soil from the slope at the temperature slightly above the road subgrade soil temperature which close to the midline,shorter time required to freeze the latter.The results further understand the moisture content and temperature variation and freezing-thawing process of silty soil subgrade,in order to further study the subgrade freezing silt provides theoretical support.