Question

(a)

A constant head permeability test was performed for the soil
specimen. The sample length was 90 mm and sample diameter was 75
mm. The total head loss across the sample was measured to be 635
mm. The flow rate was measured and it took 278 seconds to fill up a
1-litre beaker. Estimate the coefficient of permeability (k), in
m/s, based on results of the constant head test.

(b)

If a falling head test was conducted on the same soil specimen in
part (a) (with same dimensions), with a standpipe diameter of 4 mm
and initial total head difference of 1.05 m, how long would it take
for the water level to drop by 1 m through the standpipe? Is it
practical to use this test to determine k value of the soil?

(c)

The soil specimen in parts (a) and (b) were obtained from a project
site, where the soil layer was 10 m thick, overlying an impermeable
rock layer. A pumping test was conducted at the site.

Before the pumping started, the water table was found to be 2 m
below ground surface. At the pumping rate (flow rate, q) of 0.015
m3/s, the water table dropped by 1.5 m at a borehole 10 m away from
the pumping well. What would be the drop in water table at another
observation borehole, located 5 m away from the pumping well?

Answer #1

**Solution (a) :**

We have ,**for constant head permeability
test:**

**q = k * i * a** = k * ( h/L) * A

**k = q*L/(h.A)**

**Data given :** Discgarge (q) = 10-3/(278) m3/s =
3.60 * 10-6 m3/s

Sample length = 90 mm = 0.09 m

Head loss (h) = 635 mm = .635 m

Area = (3.14/4) * d2 = 4.42 * 10-3 m2

substitute these value in above equation ,

k = 3.6* 10-6 * .09/ ( .635 * 4.42 * 10-3)

**k = 1.154 * 10-4 m/s.**

**Answer (b) :**

**Falling head permeability test,**

Permeability is given by, **k = (aL/At) * ln(
h1/h2)**

Given data : Area of stand pipe (a) = (3.14/4) * 0.0042 = 1.26 * 10-5 m2.

initial head difference ( h1) = 1.05 m & final head difference (h2) = 1.05-1=0.05 m

Putting all the given values in equation we have,

1.154 *10-4 = ((1.26 * 10-5 * .09)/ (4.42 * 10-3 *t)) * ln( 1.05/.05)

**t = 6.768 seconds.**

Q1. A standard constant head permeability test was performed on
a coarse sand soil sample that was 100 mm in diameter and 200 mm in
length. The measured discharge through the sample was 2.16 litres
per minute with an equivalent constant head loss of 845 mm (acting
over the entire sample length). At the end of the test, the total
mass of the sample was recorded 3.142 kg and the moisture content
of the sample was measured at 24 %....

Length of soil sample for constant head permeability test is 30
cm, Area of specimen is 177cm2, constant head difference is 50 cm,
total volume of water collected in 5 min is 350003. Calculate the
hydraulic conductivity of the soil. A) 2.85 x 103cm/sec D) 1.09 x
102cm/sec B) 1.09 x 10" art/sec C) 3.95 x10' cm/sec

A Test was Performed according to the following data:
Volume of specimen, V = ? = ?? 2 L (cm2 )
.
418.03
Specific gravity of soil solids, Gs
2.66
Mass of specimen tube with fittings, (g)
238.4
Mass of tube with fittings and specimen, W2 (g) Dry density of
specimen,
9365
Void ratio of specimen,
0.53
(Note: pw = 1 g/cm3
If K=QL/Aht (cm/s) and Gs =2.66 , Volume of Specimen is 418.03
cm3
Determination of coefficient of permeability...

Give a definition of Permeability test
List the Equipments and tools needed to perform the costant
Head Test
A Test was Performed according to the following data
Volume of specimen, V = ?=??2L
(cm2) .
418.03
Specific gravity of soil solids, Gs
2.66
Mass of specimen tube with fittings, (g)
238.4
Mass of tube with fittings and specimen, W2
(g)
Dry density of specimen,
9653
Void ratio of specimen,
0.53
(Note: pw = 1 g/cm3)
■
If K=QL/Aht (cm/s) and...

Both falling head and constant
head permeability tests are common experiments to obtain
soil sample hydraulic conductivity.
Please provide 3 recommendations for each experiment to improve
their accuracy of test results.

1) A Standard Penetration Test (SPT was performed at a depth of
10 ft in sand of unit weight 125 lb/ft3. The N-value was
found to be 30. Determine the corrected N-value.
CN = 0.77 x log10 (20/po)
A. 32
B. 34
C. 37
D. 40
2) A standard penetration test was conducted in the field. The
boring logger recorded following three readings for 6 inch interval
of penetration: 1/2/3. What is N-value?
A. 3
B. 5
C. 2
D....

1. Operative Report
PREOPERATIVE DIAGNOSIS: Biliary colic
POSTOPERATIVE DIAGNOSIS: Biliary colic
OPERATIVE PROCEDURE:
1. Laparoscopic Cholecystectomy with intraoperative
cholangiogram
2. Tru-Cut liver biopsy
ANESTHESIA: General
DRAINS: None
COMPLICATIONS: None
ESTIMATED BLOOD LOSS: Minimal
DETAILS: After the induction of general anesthesia, the
patient's abdomen was prepped and draped sterilely. A small
supraumbilical incision was created. The abdomen was entered. The
peritoneal cavity was cannulated with a Veress needle. Position was
confirmed with the drop test. The abdomen was insufflated to 250...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 16 minutes ago

asked 46 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 3 hours ago

asked 3 hours ago