砂层在黄土中的阻水性及减渗性的研究

根据土壤水的能量原理,对砂层在黄土中的阻水作用进行了室内一维土柱的入渗试验研究及教学模拟,结果表明:在黄土中设置砂层,不仅具有良好的阻水性,使下渗水流在一定限度内滞留于砂层以上的土体内,增加了上层土壤的持水能力;而且还具有减渗性,使下渗水量及入渗峰面的湿润速度明显减小,并且还可将下渗的非线性过程转化为线性过程,从而使整个入渗过程进入一个具有较小入渗率的稳渗阶段。该研究结果对在黄土地区采用设置砂层的方法,作为水利、建筑工程以及西北农村窑洞民居防渗、减渗的一项工程技术措施,提供了理论依据。

Experiment and Study on Water-Tightness and Infiltration Reduction of Sand Layer in Loess Soils

Based on the energy theory of soil water, this paper deals with the effect of watertight-ness of sand layer in loess soils through the lab experiments on water infiltration into soil column as well as mathematical simulation. The results showed that sand layer set up in the loess soils is characterised not only by better water-tightness, which can make infiltration flow stay over sand layer in soil body to a certain limit exent so as to improve water retaining capacity in upper soil layer, but also by infiltration flow as well as the wetting velocity and also convert the non-linear process of infiltration into the linear process, thus resulting in the whole infiltration process to enter the stable infiltration stage with a smaller infiltration rate. Accordingly the results of this project have provided the theroretical base for the adoptation of setting up sand layer in the loess soil in Northwest China as an important technical engineering practice for the inflitration prevention and reduction to water conservancy work and architectural engineering as well as cave-dwellings of the local inhabitants.