非饱和重塑黄土基质吸力变化特征与物理性质的关系

Correlations between matric suction of unsaturated remoulded loess soils and their physical properties

本文以兰州重塑黄土为对象,通过室内试验分析6组非饱和重塑黄土土-水特征曲线分段特征值与主要物性指标的统计关系,探讨了非饱和重塑黄土物理性质对其基质吸力变化特征的影响。结果表明,对于非饱和重塑黄土,分段特征含水量、特征饱和度、特征基质吸力与干密度关系密切,与颗粒级配关系较弱。随干密度增加,过渡区特征饱和度、残余饱和度线性增加,饱和含水量、过渡区特征含水量线性降低,残余基质吸力及过渡区特征基质吸力分别为线性及非线性增加。过渡区特征饱和度、残余饱和度与土体中粘粒含量线性正相关,与粉粒含量负相关。饱和含水量与粉粒含量线性正相关,残余基质吸力与其线性负相关。重塑黄土的微观结构显示这些关系受制于土体的孔隙结构和颗粒间的相互关系。

This paper shows the investigation results of the effect of physical properties of remoulded loess soils on the variation in the matric suction of unsaturated remoulded loess soils via laboratory test,which was particularly focused on the analysis of correlations between main physical properties and characteristic values at some critical points of soil-water characteristic curves.The results show that,for the remolded loess soils,water content,saturation and matric suction at some critical point of the soil water characteristic curves,have closer correlations with dry density than that with particle size distribution.With the increase of dry density,characteristic saturation of transition zone and residual saturation increase linearly,saturated water content and characteristic water content of transition zone decreases linearly,and residual matric suction and characteristic matric suction of transition zone respectively increases linearly and nonlinearly.Specifically,both characteristic saturation of transition zone and residual saturation have linear correlation with clay content,while fairly reverse linear correlation with silt content.Saturated water content has linear correlation with silt content,while residual matric suction has reverse linear correlation with it.Microstructures of the soils illustrated that the insights of these correlations are controlled by the pore structure and relationships between particles.