结合水对高液限土变形行为的影响
Effect of adsorbed water on compression behavior of high liquid limit soils
张锐 1肖宇鹏 2高乾丰 1郑健龙1
作者信息
- 1. National Engineering Laboratory of Highway Maintenance Technology(Changsha University of Science&Technology),Changsha 410114,China;School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China
- 2. School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China
- 折叠
摘要
为研究结合水对高液限土变形的影响机制,并建立有助于工程应用的压缩系数预估公式,本文选取了高液限黏土、高液限粉土和黏土质砂展开室内试验研究.通过不同浓度的NaCl溶液对土样初始结合水进行控制,用热重分析法测定了3种土样在不同浓度下的结合水含量;通过液塑限联合测定仪测定了不同浓度下液塑限的变化规律;为了研究结合水对固结特性的影响,采用固结法对3种土样在不同浓度的盐溶液下进行了饱和固结试验.结果表明:随着盐溶液浓度的增加,其结合水含量降低,液塑限也降低;对于相同初始孔隙比的饱和土样,压缩指数随结合水含量的增加而降低;在相同修正孔隙比条件下,不同土体的压缩曲线趋于一致.根据本文结果及已有文献数据,建立了初始孔隙比与压缩指数的预估公式,由于结合水在土中起到了一定骨架作用,与未修正的孔隙比相比,修正后的孔隙比可将不同土样压缩行为进行归一化,从而提高压缩指数预估公式的相关性.
Abstract
The aim of this study is to reveal the mechanism underlying the influence of adsorbed water on the deformation of high liquid limit soils, and establish the prediction equation of compressibility coefficient, which is helpful for engineering application. high liquid limit clay, high liquid limit silt and clayey sand were selected for laboratory tests. The initial adsorbed water of the soil samples was controlled by different concentrations of NaCl solution, and the adsorbed water contents of three soil samples in different concentrations of salt solution were determined by thermogravimetric analysis. Meanwhile, the variations of liquid limit (LL) and plastic limit (PL) at different concentrations were also determined by the liquid-plastic limit combine tester. In order to study the effect of adsorbed water on the consolidation characteristics, saturated consolidation tests were carried out on three soil samples under different concentrations of salt solutions. The results show that as the concentration of salt solution increases, the adsorbed water content, LL and PL decrease accordingly. For saturated soil samples with the same initial void ratio, the compression index decreases with an increase in adsorbed water content. At the same modified void ratio, the compression curves of different soils tend to be consistent. Based on the results of this study and those available in the literature, the prediction equations of initial void ratio and compression index were established. Compared with the unmodified void ratio, the modified void ratio can normalize the compression behavior of different soil samples since the adsorbed water plays a skeletal role in the soil. Thus, the precision of the prediction equation of compression index can be improved using the modified void ratio.
关键词
高液限土/结合水/固结/孔隙比/压缩系数Key words
high liquid limit soil/adsorbed water/consolidation/void ratio/compressibility引用本文复制引用
基金项目
National Natural Science Foundation of China(52278432)
Highway Industry Standard Compilation Project of Ministry of Hainan Province,China(2021-Z043)
出版年
2023
NETL
NSTL
维普
万方数据