非饱和土路基毛细作用分析

为研究毛细作用对非饱和土路基土含水量的影响,分析了非饱和土路基毛细作用现象机理,探讨了毛细水上升高度的影响因素,在土颗粒等粒径假设下导出了毛细水上升高度与时间、土颗粒大小排列关系及毛细水半径效应;利用多孔介质理论建立路基土毛细作用多孔介质模型,探讨了多孔介质模型下的非饱和土渗透率关系;基于毛细水流质量守恒和路基毛细作用模型及土-水特征曲线,求得路基毛细水达到最大高度所需要的时间和单位体积路基土毛细作用下含水量的变化关系。路基含水量与地下水位(GWL)具体试验观测数据对比表明:毛细作用对路基含水量变化的影响较显著。

Analysis of Capillary Effect in Unsaturated Roadbed

The capillary mechanism in unsaturated roadbed and the factors that influence the height of capillary were discussed for the purpose of investigating the effect of capillary on the water content of unsaturated roadbed.The relationship among the capillary rising height,time and soil size as well as the capillary radius effect were studied based on the hypothesis of the uniform soil granule.The porous medium model of capillarity in roadbed was established and the penetrate rate of the unsaturated soil was discussed by using the theory of porous medium.The time that the capillary water reaches the highest height was acquired based on the conservation of current quality.The formula which describes the variation of water content in unit soil of roadbed under capillary effect was deduced based on the established model and soil-water characteristic curve.Meanwhile,the variation of water content in roadbed because of capillarity was proved by the trial data of water content in roadbed and ground water level(GWL),which show that the capillarity has notable effect on the water content of roadbed.