8/13/2019 Permeability 1
2/2
LOC. :Project Title:
Borehole No. Date Tested Tested by:
Sample: Dept From: to Calculated by:Very dark peggasse mix with
dark grey silty organic clay. .
Sample Dimensions:
2246 g Diameter 10 cm
1703 g Area (A) 78.55 cm 2
543 g Height (L) 9 cm
Volume 706.95 cm 3
Density 0.768 g / cm
2660 g
1703 g
957 g
Test Data
Standpipe = 250 ml Burette Area Standpipe 1.00 cm 2
Test No. h1, cm h2, cm t, sec Qin, cm3 Qout, cm3 T, deg. C Test
No. h1, cm h2, cm t, sec T, deg. C
1 250 150 600 100 26 1
2 250 150 590 100 26 2
250 150 595Area of standpipe (a )= 1.00 cm 2
Coefficient of Permeability at temperature 26 deg. C (kT) = a *
L ln h1/h2 = ((1* 9)/(78.55*595))*LN(250/150) = 0.0000984
cm/sec
A * t
Coefficient of Permeability at temperature 20 deg. C (k20) = a *
kT = (NT / N20)* kT= (0.00874/0.01005)*K33= 0.00008555 cm/sec
Where : a = cross sectional area of burette, cm 2
A = cross sectional area of soil sample, cm 2
h1,h2 = hydraulic head across sample at beginning and ending of
test.
NT, N20= viscosities of water at the test temperature and at 20
deg. C.L = length of sample or f low path that produces the head
difference.
t = time of test
Mass mould + frame + wet soil
Mass mould + frame
Mass Wet Soil
Average
COEFFICIENT OF PERMEABILITY - FALLING HEAD METHOD
July 2012
After
T.I
E.A
Before
Mass mould + frame + dry soil
Mass mould + frame
Mass Dry Soil
