Effective unsaturated hydraulic conductivity of layered sands
Effective unsaturated hydraulic conductivity of layered sands
复制标题
层状砂的有效不饱和导水率
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
D. Harvey
中科院分区：
文献类型：
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作者：
T. Yeh;D. Harvey
准确估计非饱和非均质土的现场尺度水力传导率是非常困难的。在本研究中，各种确定非均质砂岩有效导电性值的方法与实验室测量结果进行了比较。采用稳态通量控制方法测量了两种均质砂和由两种均质砂组成的一层砂的非饱和导流系数K（ψ）。用直接平均法对两种均质砂的平均K（ψ）曲线与实测层状砂的K（ψ）数据进行了比较。结果表明：粗砂和中砂的水力导吸曲线几何平均值与层状砂的实测水力导吸曲线接近；将观测到的吸力方差和有效水力导率与随机理论推导的表达式进行了比较。结果支持随机方法。
Accurate estimates of field-scale hydraulic conductivities of unsaturated heterogeneous soils are very difficult to obtain. In the present study, various approaches to determining effective conductivity values for heterogeneous sands are compared with laboratory measurements. The unsaturated hydraulic conductivity, K(ψ), of two homogeneous sands and one layered sand composed of the two homogeneous sands was measured using the steady-state flux control method. The averaged K(ψ) curves of the two homogeneous sands using a direct averaging approach were compared with the measured layered sand K(ψ) data. The result shows that the geometric mean of hydraulic conductivity-suction curves of the coarse and medium sands approximates the measured hydraulic conductivity-suction curve of the layered sand. The observed suction variance and effective hydraulic conductivity were compared with expressions developed from a stochastic theory. The results support the stochastic approach.