A centrifugal model test study of lime-improved expansive soil under drying and wetting circles

In order to study the engineering properties of the expansive soil improved with lime of the Nanning high-speed railway embankment under drying and wetting circles, three times of centrifuge model tests under drying and wetting circles were carried out on the embankment model based on the similarity principle, and the effects of time, depth as well as drying and wetting circles on the variations of earth pressure, suction, moisture content and temperature were explored. The research results show that the established similarity relationship of evaporation is well feasible to the evaporation time and the intensity control during the centrifugal model test. The deformation of the embankment slope is closely related to the moisture content. A few cracks occurred in the process of evaporation with the maximal width of less than 2 mm, and the cracks disappeared during the rainfall process. After three times of drying and wetting circles, the entire deformation was not obvious. The earth pressure, suction, moisture content and temperature show obvious changes with time and depth. The influence of the atmosphere decreases with the increasing depth, and the effect depth is 8.0 m. The results of this study can provide some suggestions for high railway embankment construction with lime-improved expansive soil. It is of certain engineering application value.