Migration law of salt in compacted aeolian sandy soil

Aiming at the phenomenon of salinization diseases in the aeolian sand subgrade in desert areas, the change laws of water, heat and salt in compacted aeolian sand soils are investigated. The self-made aeolian sand column test device with sodium salinite soil as its foundation is based on the real-time monitoring data from natural environment for 6 months (June to December) to analyze the temporal and spatial distributions and migration characteristics of water, heat and salt in the compacted aeolian sandy soil layers. The result shows that affected by the external environmental temperature, the compacted aeolian sandy soil layers affect the severe (0~50 cm) and weak (50~120 cm) areas. As the depth of burial increases, the internal temperature of the soil column tends to be flat, and the temperature of each layer reaching the peak has a hysteresis effect. Under the effect of the concentration gradient of the salinity content of the salt-containing underlay surface and the compaction aeolian sand deposit, the deep area of the compacted aeolian sand soil layer is moved in by salt, and it is composed of nothing. The accumulation of salt in the aeolian sandy soil layer lays the foundation for the further migration of salt. Affected by the external temperature, the shallow layer of soil is affected by the change of water storage and evaporation, which promotes the gradual migration of water carrying salt in the compacted aeolian sand layer. The salt has a "high-low-high" distribution pattern throughout the depth of the soil. Affected by the external environmental loads, the shallow salt content in the compacted aeolian sandy soil layers will gradually accumulate, and from less to more, it will form salinization diseases over time.