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The following calculations are used in this test:

 

Hydraulic Gradient

 

i = Δh / L

 

where,

i        = Hydraulic gradient

Δh        = Difference in manometer levels

L        = Manometer tap distance

 

Discharge Velocity

 

v = (Mw - Mc) / t / (π * D2 / 4)                Water collected measured by mass

 

v = Vc / t / (π * D2 / 4)                Water collected measured by volume

                 

where,

v        = Discharge velocity

Vc        = Volume of water collected

Mw        = Mass of container and water collected

Mc        = Mass of container

t        = Sampling duration

D        = Specimen diameter

 

 

Hydraulic Conductivity

 

k = v / i

 

where,

KT        = Hydraulic conductivity