Model test study on infiltration law of remolded unsaturated loess

In order to study the infiltration law of unsaturated loess, the infiltration model test of remolded loess is carried out, the change of volume moisture content at different positions and the development process of wetting front are analyzed, the development and change law of infiltration water content in horizontal and radial direction is studied, and the infiltration depth at different time is calculated by Green-Ampt model considering air pressure, which is compared with the measured value. The research shows that the change trend of volume moisture content at different measuring points is basically the same, and it would go through six stages: stability-rapid growth-reaching peak-rapid decrease-regrowth-maintaining stability; and the immersion infiltration process is affected by infiltration depth, infiltration path, viscous resistance and air pressure. The deeper the infiltration depth and the farther away from the central axis, the more delayed the development of wetting front and the smaller the infiltration rate. As the depth increases from 0 cm to 100 cm, the infiltration rate decreases from 14.93 cm/h to 1.67 cm/h. The relationship between vertical infiltration rate and infiltration depth at different positions is fitted, and it is found that the vertical infiltration rate and the infiltration depth have a quadratic relationship, and the fitting degree is above 0.9. Radial water migration is the result of the combined action of radial water diffusion and vertical water infiltration in the upper part of the depth, so it is faster than vertical water infiltration. The development trend of wetting front in the model is consistent with the measured vertical infiltration, however, the calculated value of infiltration depth is larger than the measured value at the late infiltration stage. The research results can provide reference for the study of loess foundation infiltration.