盐渍土区路基土层级配特征及阻盐效应分析

Analysis of gradation characteristics and salt-resistance effect of subgrade layer in saline soil area

为研究盐渍土区域路基土层级配关键技术参数的选取与阻盐效应的关系,对盐渍土区已建路基土层开挖采样,分别进行颗粒分析实验、易溶盐含量测定和毛细管水上升实验,分析盐湖区盐渍土的颗粒级配、盐渍化强度和水盐运移上升高度计算方法。结果表明:研究区盐渍土为0.25~0.075 mm粒组含量有利于水盐运移,>0.25 mm粒组含量不利于水盐运移。路基阻盐隔断层关键参数宜选择:级配2.0~5.0 mm粒组含量大于75%,厚度在300~1 000 mm,可有效隔断路基土层中的水盐运移,阻盐效果良好。

The purpose of this study is to explore the relationship between the selection of the key technical parameters and the salt-resistance effect in subgrade soil layer in saline soil area. The particle analysis experiment,the soluble salt content determination and the capillary water rise experiment were carried out on the soil excavated from of the subgrade in saline soil area,and the calculation method of the grain gradation,salinization intensity and the rising height of water and salt migration of saline soil from salt lake area were analyzed. The results show that the content of saline soil（ 0. 25 ~ 0. 075 mm） in the study area is favorable to water and salt migration,and saline soil group with greater than 0. 25 mm is unfavorable to water and salt migration. The key parameters of subgrade salt barrier should be selected. Gradation of 2. 0 ~ 5. 0 mm with more than 75% granule group content and,thickness in 300 ~ 1 000 mm,can effectively cut off the roadbed soil water and salt migration. The effect of salt resistance is good.