【摘要】 本文主要介绍关于非饱和水在双层孔隙介质中渗流定性实验的方法和主要结果。使用由粗 -细颗粒石英砂层 (第 类组合 )及黄土 -石英砂层 (第 类组合 )组成的两类双层孔隙介质 ,用可视玻璃箱作为实验箱体 ,分别采用红色罗丹明 B和曙红 Y为示踪剂进行渗流定性实验。在由介质上表面定时喷淋清水条件下 ,分别观测了当示踪剂在第 、 两类双层孔隙介质“顶层释放”及示踪剂和石英砂混合后铺设在黄土内 (第 类组合 )的“中间释放”情况下 ,示踪剂的渗流路径和扩展情况。无论在“顶层释放”还是在“中间释放”情况下 ,尽管粗颗粒层很薄 ,但均观察到非饱和水的绕流现象。距释放时间较长时 ,“顶层释放”的示踪剂在粗颗粒层下方中央形成一条明显的空隙 ;而由土体“中间释放”的示踪剂在粗颗粒层下方中央形成一条狭窄的示踪剂色带 ,两者形成了互补景象。另外 ,在未喷水的静置条件下 ,“中间释放”的示踪剂随着静置时间的增大而向上、下两侧黄土中的扩展范围也在逐渐增大更多还原

【Abstract】 The method and main results of qualitative experiment of unsaturated water vadose through two layer porous media is introduced in this paper. Two types of compositions of porous media, i.e. coarse fine quartz sand (Type Ⅰ) and quartz sand loess (Type Ⅱ), were used for the experiment. The experiment box is made of glass. And tracers used for the experiment are Rhodamine B and Eosin Y. The vadose path and expansion of tracers through two layer porous media were observed under artificial sprinkling from top surface for “top release” of Type Ⅰ and Ⅱ as well as for “middle release” of Type Ⅱ, respectively. The detouring flow phenomenon of unsaturated water through two layer porous media is observed, whether they are made up of coarse and fine quartz sand or quartz sand and loess, even though the coarse particle layer is very thin. An obvious space is formed at the lower part of the coarse particle layer at longer time of releasing tracer from the top. And a narrow tracer zone is formed at the lower part of coarse particle layer for releasing tracer from mixed tracer and quartz sand layer in the middle of loess. The complementary scenario is observed for both mentioned above. Moreover, the tracer, which is initially put in coarse particle layer within loess, expanded up and down into loess and the expansion extent increases with retention period under no water sprinkling. (更多还原