| 毛雪松,侯仲杰,孔令坤.风积砂水分迁移试验研究[J].水利学报,2010,41(2): |
| 风积砂水分迁移试验研究 |
| Experimental study on moisture migration of wind-blown sand |
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| DOI： |
| 中文关键词: 水分迁移 迁移动力 渗透强度 土水特征曲线 |
| 英文关键词: moisture migration migration force infiltration intensity characteristic curve of the soil-water |
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| 中文摘要: |
| 为了研究水分在风积砂中的迁移规律，以不同初始含水率、不同干密度的陕北风积砂为研究对象，在不损坏试样的前提下在试验室进行含水率的实时监测。分析了风积砂内部含水率、渗透强度的时空变化规律，得到了土水特征曲线，揭示了风积砂的水分迁移特征。研究表明：在等温条件下，基质势和重力势是风积砂中水分迁移的主要动力；同一干密度下、不同初始含水率的风积砂中由于基质吸力引起土体中水分迁移的湿润锋高度相同，补水量随着初始含水率的增大而减小，渗透强度随着初始含水率的增加呈现递减趋势；风积砂土水特征曲线的分布包含饱和段、过渡段和不变段，其中同一干密度土样的曲线的饱和段水分分布规律基本相同，过渡段内水分变化梯度存在较大差异，水分变化梯度随初始含水率的增大而逐渐减小；对于不同干密度的风积砂，在相同初始含水率下，补水量和渗透强度随干密度的增加而减小，毛细水上升高度随着干密度的增加而增大。 |
| 英文摘要: |
| The migration characteristics of the moisture in wind-blown sand samples collected from the north of Shanxi province were studied in laboratory. Real time water content in these samples without being destroyed were monitored under different initial water content and different dry density. The spatiotemporal distribution of the inside water content and the infiltration intensity were analyzed. The characteristics curve of the soil-water was derived and the migration characteristics of the moisture have been discovered. The experimental results show that the matric potential and the gravity potential are the dominant factors to propel the moisture migration under isothermal condition. The height of the wetting front of the moisture migration in the wind-blown sand with the same dry density and different initial water content are nearly the same，due to the matric suction. The supply water content decreased with the increasing of the initial water content.The infiltration intensity of the wind-blown sand with different initial water content is also decreased with the increasing of initial water content. The characteristic curve of the soil-water in the wind-blown sand are consisted of three stages: saturation stage，transition stage and invariant stage. The distribution law is basically the same in the saturation stage. There is great difference at the moisture gradient in the transition stage， and the moisture gradient decreases with the increasing of the initial water content. With the same initial water content and different dry density，both the supply water content and the infiltration intensity of the samples decreased with the increasing of the dry density. The rising height of the capillary water in the samples enlarged with the increasing of the dry density. |
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