Geotechnical Permeability Calculator
Calculate soil permeability using various laboratory and field methods
Constant Head Test
Falling Head Test
Field Methods
Constant Head Test Parameters
Soil Properties
Constant Head Test Method
The constant head test is used for coarse-grained soils (gravels and sands) where water flows freely through the sample.
Darcy’s Law: Q = k × i × A
Where: Q = flow rate, k = coefficient of permeability, i = hydraulic gradient, A = cross-sectional area
Permeability: k = (Q × L) / (A × h)
Where: L = sample length, h = head difference
Permeability Results
Coefficient of Permeability
0.033 cm/s
Medium permeability – typical for clean sand
| Parameter | Value | Units |
|---|---|---|
| Hydraulic Gradient | 5.0 | – |
| Flow Velocity | 0.167 | cm/s |
| Reynolds Number | 0.33 | – |
Permeability Scale
High
>10⁻² cm/s
Medium
10⁻³ – 10⁻² cm/s
Low
10⁻⁵ – 10⁻³ cm/s
Very Low
<10⁻⁵ cm/s
Typical Soil Permeabilities
Clean Gravel
10⁻¹ – 10⁰ cm/s
Clean Sand
10⁻³ – 10⁻¹ cm/s
Fine Sand
10⁻⁴ – 10⁻³ cm/s
Silt
10⁻⁶ – 10⁻⁴ cm/s
Clay
10⁻⁹ – 10⁻⁶ cm/s
Comments are closed, but trackbacks and pingbacks are open.