Fluctuation effect of equilibrium moisture content of low subgrade under high groundwater level in hot and humid climatic regions

moisture content of subgrade was analysed. Taking the typical climate and the subgrade soil in
Fujian province as an example, three technological methods - theoretical analysis, numerical
simulation and indoor simulation experiment - were adopted in the investigation of the fluctuation
effect of equilibrium moisture content of subgrade. The results show that, computing results from
the formula of the equilibrium moisture content of subgrade, the numerical simulation results are
closer to each other in consideration of the temperature effect. The test results can not reflect the
relationship between the equilibrium moisture content and the height of embankment. The
maximum fluctuation range of the equilibrium moisture content of the cement concrete pavement is less than 2 percent in Fujian area, and this phenomenon presents the effect of the moist-hot
climate on the equilibrium moisture content. Equilibrium moisture content presents a declining
trend with the increment of the temperature and the compactness. So, if matric potential
considering temperature indirectly reflects the influence of thermal potential, then the equilibrium
moisture content of low subgrade under high groundwater level can be estimated approximately.
The fluctuation range of equilibrium moisture content in different layers of subgrade can be
reduced effectively with the increment of the roadbed compaction degree.