The study of hydraulic characteristics in unsaturated soils is crucial for analyzing seepage and deformation of loess during engineering activities.This research focuses on loess from the southern suburbs of Xi'an City.The filter paper method and saturated salt solution method were employed to measure soil-water characteristic curves un-der three dry density conditions with varying degrees of wetness.The Childs & Collis-George model was used to pre-dict unsaturated permeability coefficient,examining the impacts of dry density and wetting/drying cycles on these characteristics.Results indicate that unsaturated permeability coefficient increased with volumetric moisture content and decreased with matric suction,dropping significantly by 4-5 orders of magnitude within the 0-5 MPa range.Due to bottleneck effects and moisture-reduction-induced shrinkage,the variation in permeability coefficient during wetting stages was smaller compared to drying stages.Furthermore,with dry density increasing from 1.719 g/cm3 to 1.834 g/cm3,permeability coefficient decreased by two orders of magnitude.The unsaturated permeability coeffi-cient of compacted loess varied by a factor of up to 3-4 between wetting and drying phases.
关键词
压实黄土/土-水特征曲线/干密度/增减湿/非饱和渗透系数
Key words
compacted loess/soil-water characteristic curve/dry density/wetting and drying/unsaturated permea-bility coefficient
维普
万方数据