Experimental Study on Moisture Changes in Shallow Unsaturated Loess under Atmospheric Action and its Influencing Factors

Moisture variations in shallow loess soils induce diseases like sinking and cracking in road foundations and pavements, whereas temperature and stress changes in shallow loess soils are determined by moisture changes and influencing variables. To study the moisture change pattern of shallow unsaturated loess in semi-arid northwest China under atmospheric action. Model experiments of remolded loess were conducted, with remolded soil samples being measured under various starting circumstances. The findings of the experiments show that atmospheric activity has less impact on internal moisture changes in soils with a high dry density. The internal moisture migration of the soil sample is affected by heat transfer under atmospheric action at the same depth. The interior pores of the soil progressively link along the depth direction as a result of atmospheric action, and the water gradually distributes higher, enabling leftover water to evaporate. The longer the atmospheric action lasts, the longer the impact of moisture change in soils with high starting volume water content lasts. Moreover, in terms of moisture fluctuation at the subgrade, soils with an initial volume moisture content of less than 23% are essentially unaffected by atmospheric activity.