Water Transport Characteristics and Their Impaction on Stability of Unsaturated Xiashu Loess Slopes During the Entire Process of Rainfall Infiltration

Abstract

The Xiashu loess in the middle and lower reaches of the Yangtze River with typical aeolian characteristics is widely distributed in the hilly areas and is the main kind of landslides in this area. The paper reveals the infiltration process of the Xiashu loess slope under different rainfall intensity conditions on the basis of on-site artificial rainfall simulation tests and laboratory experiments. The distribution of pore water pressure inside the Xiashu loess slope under different rainfall intensity conditions were compared and analyzed. The relationship between rainfall intensity and water content at different depths was clarified, and the relation function among rainfall intensity conditions, slopes, and the ultimate depth and critical rainfall intensity of the Xiashu soil slope landslide is proposed. The research results indicate that: (1) the infiltration rate and depth of the soil at the foot of the slope are greater than those at the top and middle of the slope; (2) an increase in the rainfall duration is found to cause an increase in slope infiltration depth; (3) an increase in the rainfall duration can lead to a more significant influence of the infiltration depth under the slope angle; (4) the infiltration depth of rainfall with low intensities and long durations is larger than that of high intensities and short durations. Finally, the ultimate rainfall infiltration depth under different slope angles and rainfall conditions was determined. The research results can be used to forecast the Xiashu loses soil landslide scale, providing theoretical basis for early warning of instability of Xiashu loess slope under different unfavorable conditions.