清水和渗滤液对2种黄土垫层的渗透对比试验

Comparative Experiment on the Permeabilities of Clear Water and Leachate in Two Kinds of Loess Cushions

[目的]探讨清水和渗滤液各自的渗透性能以及对入渗的影响。[方法]以马兰黄土、垃圾渗滤液、自来水为试验材料,对清水和渗滤液通过变水头渗透试验和一维垂直连续渗透土柱模拟对比试验,分别测定了清水、渗滤液在2种黄土垫层中的非饱和入渗率和饱和渗透系数。[结果]清水和渗滤液在非饱和黄土中的入渗率随着时间变化与温度大致呈同步性变化。对最优含水率16.2%,最大干密度为1.76×103kg/m3的轻型击实黄土样品,进行饱和变水头渗透试验,清水与渗滤液在渗透系数出现稳定的时间上相差较大,后者天数是前者的2倍。饱和与非饱和渗透时,清水的渗透系数和入渗率都大于渗滤液的。[结论]最优含水率下的击实马兰黄土可以作为填埋场人工防渗膜下的保护层。

[Objective] The aim was to discuss the permeabilities of clear water and leachate and their effect on infiltration. [Method] With the Malan loess, landfill leachate and tap water as tested material, the unsaturated infiltration rate and the saturated permeability coefficient of clear water and leachate in two kinds of loess cushions were measured through a series of comparative simulated experiments of pemeability with the various water head and the vertical one-dimensional continuous permeation in soil columns [Result] The infiltration rate of rinsing and leachate in the unsaturated loess with the change of time approximately showed synchronism change with temperature. The loess sample of light hit-solid with the optimum moisture content 16.2% and the greatest dry density 1.76 × 10^3 kg/m^3 was made the penetration test of saturation various water head, the rinsing and leachate had big difference on the steady time of permeability coefficient, the days of latter was 2 times with the former. When saturation and non-saturation were infiltrated, the permeability coefficient and permeability rate of rinsing were greater than leachate. [Conclusion] It is indicated that the compacted Malan loess with the best water content can be expected as an ideal protective layer under the artificial impermeable membrane of the landfills.