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

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 °C and 1.30 g/cm3, 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.