Measurement and engineering application of adsorbed water content in fine-grained soils  

细粒土吸附结合水含量的测定及工程应用

作　　者：ZHANG Rui XIAO Yu-peng WU Meng-li ZHENG Jian-long MILKOS B C 张锐;肖宇鹏;吴梦丽;郑健龙;MILKOS B C(National Engineering Laboratory of Highway Maintenance Technology,Changsha University of Science&Technology,Changsha 410114,China;School of Traffic and Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]National Engineering Laboratory of Highway Maintenance Technology,Changsha University of Science&Technology,Changsha 410114,China [2]School of Traffic and Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China

出　　处：《Journal of Central South University》2021年第5期1555-1569,共15页中南大学学报（英文版）

基　　金：Project(51978085)supported by the National Natural Science Foundation of China;Project(K2019G045)supported by the Science and Technology Research and Development Plan of China National Railway Group Co.,Ltd.;Project(201808430102)supported by the China Scholarship Council。

摘　　要：In this paper,the content and density of adsorbed water in fine-grained soil are determined.According to the test results,the calculation method of compaction degree of the solid-phase and void ration of soil is improved.Four kinds of fine-grained soils from different regions in China were selected,and the adsorbed water content and density of four kinds of fine-grained soils were determined by thermogravimetry and volumetric flask method.Furthermore,SEM and XRD experiments were used to analyze the differences in the ability of each soil sample to absorb water.In order to study the compression characteristics of adsorbed water,four saturated soil samples were tested by consolidation method.The results show that the desorption temperature range of the adsorbed water and its density were equal to 100−115℃and 1.30 g/cm^(3),respectively.Adsorbed water plays a positive role in keeping the compressibility of fine-grained soil at a low rate when it has high water content.Besides,adsorbed water can be a stable parameter and is difficult to discharge during the operation period of subgrade.The settlement of fine-grained soil embankment is predicted by engineering example,and compared with the result of conventional calculation method.The results show that it is more close to the field monitoring results by using the improved void ratio of soil as the parameter.本文测定了细粒土中吸附水的含量及其密度,并根据测试结果改进了固相压实度和土的空隙率计算方法。选取了我国不同地区的4种细粒土,用热重法和容量瓶法测定了4种细粒土的吸附水含量和密度;利用扫描电镜和X射线衍射分析了各土样吸水能力的差异。为了研究吸附水的压缩特性,采用固结法对4种饱和土样进行了试验。结果表明,吸附水的解吸温度范围为100~115℃,密度为1.30 g/cm^(3);吸附水对高含水量细粒土保持低压缩性有积极作用。此外,在路基运营期,吸附水保持一个稳定值,且难以排出。通过工程实例对细粒土路堤的沉降进行了预测,与传统的计算方法相比,采用改进后的空隙率作为参数进行计算更接近现场监测结果。

关 键 词：adsorbed water volumetric flask method thermogravimetric analysis method void ratio SETTLEMENT 

分 类 号：TU41[建筑科学—岩土工程]