Columnar experimental study on rainfall infiltration of basalt residual soil landslide in Feiyun River Basin of Zhejiang Province

Basaltic residual soil is widely developed in Feiyun river basin, which is loose, plastic and expansible. Landslides are easily induced by heavy rainfall and action of human engineering in this basaltic residual soil stratum. In order to understand the disaster mechanism of basaltic residual soil slopes, this paper chose a typical basaltic residual soil slope in Majitou landslide to study the laws of groundwater infiltration in soil under two rainfall conditions of ABA and BAA by soil column tests. The results show that the volumetric moisture content of soil column gradually increases to the maximum value during the rainfall period and the decrease of volume moisture content is inversely proportional to the depth of soil column during the intermittent period. The shape of wetting front infiltration curve is linear under the two rainfall conditions and the velocity of wetting front does not change with depth but directly proportional to rainfall intensity. The response rates of soil volumetric water content are markedly different under various rainfall conditions. The conclusions obtained in this paper have important significance for the prevention and early warning of basaltic residual soil landslides.