Influence of Rainfall Infiltration on Transient Volumetric Water Content of Coal Measure Soil Slope

With coal measure soil side slope in Jiangxi's Pingxiang-Lianhua Expressway selected as the research object, GeoStudio, a finite element seepage analysis application, was adopted for numerical simulation on the variation pattern of volumetric moisture content in the side slope in rainfall as well as its spatial distribution characteristics. The results show that rainfall infiltration mainly influences the surface layer of the side slope and that its influence decreases with the increase of depth. The volumetric moisture content of undisturbed coal measure soil remains basically unchanged under the weathered layer. When soil mass permeability coefficient is less than rainfall intensity, the rainwater permeates quickly in the outermost layer of a weathering zone, but exerts a minor influence. When it is larger than the rainfall intensity, rainfall permeates slowly but exerts a major influence. When rainfall intensity reaches 8.33 x 10(-7) m/s, soil moisture contents in the superficial layers of the slope toe and halfway up the slope surface become saturated. The saturation depth is 80% of the weathered layer. When the rainfall intensity reaches 1.1 x 10(-6) m/s, it exerts a more extensive influence on the saturation area in the side slope, but the corresponding affected depth is only 50% of that in the weathered layer.