Abstract
Abstract
The agricultural flood irrigation in Jingyang South Platform, Shaanxi Province caused the rise of groundwater level, which induced a large number of loess landslides. The study of water movement in unsaturated loess under irrigation is the premise of revealing the mechanism of loess landslide. In this paper, the changes of matric suction, volume moisture content and air pressure with time at different depths of unsaturated undisturbed loess are measured by indoor soil column water infiltration test. Air pressure at each point of the soil rises to about 98 Pa in a short time after the test beginning, and keeps small fluctuation up and down during the test. At the end of the experiment, the air pressure at each point of the soil returns to zero in a short time after the upper water accumulation is eliminated. During the test, the change of infiltration rate has a significant corresponding relationship with the exhaust phenomenon at the top of the soil column, and the air resistance significantly reduces the infiltration rate of water.