AUTHOR=Zhong Lijia , Wang Bo , Zhao Xuguang , Liu Fengyin , Miao Meng , Pu Cheng 

TITLE=Study on rainfall infiltration characteristic parameters of unsaturated soil

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2023.1251765

DOI=10.3389/fevo.2023.1251765

ISSN=2296-701X

ABSTRACT=<p>The study of the rainfall infiltration mechanism of unsaturated soil has always been a hot issue in the field of geotechnical engineering. It is worth studying which parameters should be introduced to characterize the infiltration characteristics of unsaturated soil in the calculation and analysis of rainfall infiltration. In this paper, the Fredlund–Xing model was quoted in the SEEP/W module of the Geostudio software, and the transient numerical calculation of rainfall infiltration under the same rainfall duration <italic>T</italic> and different rainfall intensity <italic>I</italic> was carried out for a soil column. Three infiltration characteristic parameters were introduced: rainfall infiltration front depth <italic>WF</italic>, suction reduction depth <italic>MR<sub>n</sub></italic>, and section infiltration rate <italic>IR</italic>. The variation of these three parameters and rainfall intensity <italic>I</italic> during rainfall were sorted out and analyzed; it is indicated that <italic>WF</italic> increases with the extension of rainfall duration. <italic>MR<sub>n</sub></italic> decreases with the increase of suction reduction rate <italic>n</italic>%, and when the rainfall duration is 24 h, the maximum depth of the soil column affected by rainfall is approximately 35% of the total depth. <italic>IR</italic> is mainly affected by the rainfall intensity <italic>I</italic> and the saturation permeability coefficient <italic>k<sub>s</sub></italic>. There is a limit value for the influence of <italic>I</italic> on <italic>WF, MR<sub>n</sub></italic>, and <italic>IR</italic>, and the limit rainfall intensity under the calculation conditions in this paper is <italic>I</italic> = 2.5<italic>k<sub>s</sub></italic>.</p>