Abstract:In order to study the effects of different polystyrene plastic microsphere contents and different rainfall intermittent ratios on unsaturated infiltration of loess soil under intermittent rainfall conditions, an indoor one-dimensional soil column model was used to conduct vertical infiltration experiments. The results show that: Under the condition of intermittent rainfall cycle, the wetting front velocity of soil gradually attenuates with the increase of intermittent rainfall cycle, the wetting front velocity decay curve conforms to the logistic model, and has a good goodness of fit; Under intermittent rainfall conditions, low content of polystyrene microspheres will make the soil more sensitive to rainfall, reduce the lag time of the response to rainfall, increase the depth of the soil wetting front, and weaken the water holding capacity of the soil, while high content of polystyrene microspheres can increase the lag time of soil response to rainfall, reduce the depth of wetting front, and enhance soil water holding capacity; Compared with the 1∶1 experimental group, the wetting front depth increases under short duration, while the wetting front depth decreases under long duration. Compared with the 1∶1 experimental group, the soil had a more obvious response to rainfall, but the depth of the wetting front decreased within the same duration.