1. MEKANIKA TANAH 1 PERTEMUAN III
Determination of Permeabilty Coefficient
Oleh :
Arwan Apriyono
PROGRAM STUDI TEKNIK SIPIL JURUSAN TEKNIK
FAKULTAS SAINS DAN TEKNIK UNSOED
TAHUN 2010

2. Introduction LABORATORY FIELD CONSTANT HEAD (TINGGI KONSTAN)
FALLING HEAD (TINGGI JATUH)
FIELD
UNCONFINED AQUIFER (AKIFER BEBAS)
CONFINED AQUIFER (AKIFER TERKEKANG )
INCONSTANT WATER HEIGHT (TINGGI AIR TIDAK TETAP)

3. CONSTANT HEAD (TINGGI KONSTAN)
Lab Test
CONSTANT HEAD (TINGGI KONSTAN)
SUITABLE FOR SANDY SOIL, SAND OR GRAVEL WHICH HAVE BIG VOID RATIO VALUE
BASIC EQUATION :
Bina Nusantara

4. FALLING HEAD (TINGGI JATUH)
Lab Test
FALLING HEAD (TINGGI JATUH)
MORE ECONOMICAL FOR LONG TERM TEST
Suitable For Clayed Soil that have low k
BASIC EQUATION :
Bina Nusantara

5. UNCONFINED AQUIFER (AKIFER BEBAS)
Field Test
UNCONFINED AQUIFER (AKIFER BEBAS)

6. UNCONFINED AQUIFER (AKIFER BEBAS)
Field Test
UNCONFINED AQUIFER (AKIFER BEBAS)

7. CONFINED AQUIFER (AKIFER TERKEKANG )
Field Test
CONFINED AQUIFER (AKIFER TERKEKANG )

8. CONFINED AQUIFER (AKIFER TERKEKANG )
Field Test
CONFINED AQUIFER (AKIFER TERKEKANG )

9. Layered Soil

10. Layered Soil

11. When equilibrium flow was reached, the following data were obtained:
Example
A pumping test was performed in a well penetrating a confined aquifer to evaluate the coefficient of permeability of the soil in the aquifer.
When equilibrium flow was reached, the following data were obtained:
Equilibrium discharge of water from the well = 200 gal/min.
Water levels (h1 and h2) = 15 and 19 ft at distances from the well (r1 and r2) of 60 and 180 ft, respectively.
Thickness of aquifer = 20 ft
Coefficient of permeability of the soil in the aquifer?

12. Example
A nonhomogeneous soil consisting of layers of soil with different permeabilities.
Average coefficient of permeability in the horizontal direction and vertical direction
1.5 m
Kx = 1.2 x 10-3 cm/s
Ky = 2.4 x 10-4 cm/s
Kx = 2.8 x 10-4 cm/s
Ky = 3.1 x 10-5 cm/s
2.0 m
Kx = 5.5 x 10-5 cm/s
Ky = 4.7 x 10-6 cm/s
2.5 m