Dependence of anisotropy on saturation in a stratified sand
Dependence of anisotropy on saturation in a stratified sand
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分层砂中各向异性对饱和度的依赖性
DOI：
10.1029/wr024i005p00770
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
S. Heermann
中科院分区：
文献类型：
--
作者：
D. B. Stephens;S. Heermann
进行了一个实验室实验，以研究水从点源渗透到多孔介质中的运动，该多孔介质由填充在透明塑料罐中的细砂和粗砂交替层组成。实验的目的是证明分层材料的有效各向异性是否取决于饱和度。比流量和水头梯度方向的非共线性被用作各向异性的度量。染料被用来映射特定的放电方向和张力计被用来表征水力梯度场在不饱和，稳态条件下。结果表明，比流量和梯度的方向之间的分歧，随着压头降低而增加。从实验中确定的各向异性超过了从个别材料的水力传导率计算。
A laboratory experiment was performed to investigate the movement of water infiltrating from a point source into a porous medium comprised of alternating layers of fine and coarse sand packed in a clear plastic tank. The purpose of the experiment is to demonstrate whether the effective anisotropy of stratified materials is dependent upon saturation. The noncolinearity of the specific discharge and hydraulic head gradient directions is used as a measure of anisotropy. Dyes were used to map the specific discharge direction and tensiometers were used to characterize the hydraulic gradient field under unsaturated, steady state conditions. The results indicate a divergence between the direction of the specific discharge and gradient which increases as the pressure head decreases. Anisotropy determined from the experiment exceeds that calculated from the hydraulic conductivities of the individual materials.