CHARACTERISTICS AND LABORATORY FREEZE-THAW TEST OF SALINE SOIL IN WEST JILIN, CHINA

For the purpose of investigating the characteristic and material composition of saline soil in western Jilin, China the saline soil distribution area of Da'an in west Jilin Province was sampled during a site investigation, after which the fundamental properties of the soil were investigated in the laboratory. The soluble salt ranged from 0.28% to 0.60%, decreasing with depth from 0 to 40 cm blow the surface. Conversely, the moisture content increased with increasing depth, but showed little change beneath 40 cm. An indoor freeze-thaw simulation test revealed that the moisture migrated under the temperature gradient, while the salinity migrated upwards under the combined action of the temperature gradient and concentration gradient, with the optimum degree of compaction for salinity migration being 90%. Following freezing, the inside structure became looser, and this phenomenon was more obvious when the temperature was lower. The research provided the basis for prevention of the secondary salinization and frost heaving the disease of saline soil in western Jilin province.