Question $1.$ This is a common FE exam question! This problem is geared toward giving you

some practice in estimating permeability from lab test data.

The coefficient of permeability of sands can be directly measured in the laboratory by using

either the Constant Head permeability test or the Falling Head permeability test. Refer to the

Direct Methods discussion in the Permeability Notes handout located on Canvas.

Data from a constant head test conducted a specimen of coarse sand at one head difference

are included in the table below. Data are also included for a falling head test conducted on a

fine sand specimen.

$($a$)$ Please use the data to estimate the saturated permeability coefficient in units of $c\frac{m}{sec}$ of

the two soils $($coarse sand, fine sand$).$

$($b$)$ How do your permeability values in b$)$ and c$)$ above compare to values given in the table of

typical permeability ranges we discussed in class?

Permeability Test Data

The soil was placed in the permeability devices when dry, then the soil was saturated with water

before the test started. See the sketch of the specimen on the next page.

Diameter of all laboratory test specimens $=6\mathrm{.}2cm.,G_s=2\mathrm{.}65.$

Laboratory Data

Constant Head Permeability Test $-$ Coarse Sand

Water temperature during test $($deg$.$ C$)$: $26\mathrm{.}5$ Falling Head Permeability Test $-$ Fine Sand

$*$Water height in burette measured from datum at top of table $($base of apparatus$).$

Water temperature during test $=24\mathrm{.}0$ degrees C

Standpipe Diameter, $d=1\mathrm{.}5cm$