Date post: | 28-Oct-2014 |
Category: |
Documents |
Upload: | darya-memon |
View: | 311 times |
Download: | 10 times |
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 1
Practical#1: Obtain the Representative Soil Center by Quarter Method
To obtain a representative sample, it is required that more material be sampled than will be
tested. This material sample is then reduced in quantity without affecting the overall mix of
the sample. This is achieved with the aid of a rifle box or quartering
Apparatus: Earthen Soil, Wide Tray,
Procedure:
1. Sample each field separately and divided the field and sample each area separately. 2. Take a composite sample from each area. Collect these samples in a clean bucket or
some such wide container. 3. Do not sample unusual area. Avoid areas recently fertilized, old bunds, marshy
spots, near tress, compost piles, other non-representative locations. 4. Take a uniform thick sample from the surface to plough depth. If a spade or a trowel
is used, dig a v-shaped hole, collect the sample and place it in the bucket. 5. Pour the soil from the bucket on a piece of clean cloth or paper and mix thoroughly,
discard, by quartering, all but 1 to 2 lbs. of soil. Quarterly may be done by mixing sample well, dividing it into four equal parts, then rejecting two Diagonal opposite quarters, mixing the remaining two portions, again dividing into four parts and rejecting two opposite quarters, and so on till we get the required amount of Soil.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 2
Practical#2: Obtain the Representative Soil Center by Rifle Box Method
To obtain a representative sample, it is required that more material be sampled than will be
tested. This material sample is then reduced in quantity without affecting the overall mix of
the sample. This is achieved with the aid of a rifle box or quartering
Apparatus: Earthen Soil, Wide Tray, Riffle Boxes.
Procedure:
1. Sample each field separately and divided the field and sample each area separately. 2. Take a composite sample from each area. Collect these samples in a clean bucket or
some such wide container. 3. Then Pour the sample into riffle boxes and soil is collected in two portions 4. The Process is repeated till we get the required weight of soil for testing purpose.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 3
Practical#3: To Collect Soil Sample from the Field for Lab Test and Determine Various Properties of Soil.
(A) OVEN DRY METHOD
Apparatus: Shovel, Gunny Bag, Sample Tray, Small bowl (Container) & Digital Weight
Machine.
Procedure:
1. First of all collect the soil sample from the field, find a soil which should have a some moisture .
2. Fill about half of the gunny bag and empty it in sample tray.
3. Mix the soil so well so that consolidated particles are turned into soil, don’t remove any
vegetation if any.
4. Using digital weight machine weigh the weight of small bowl (Container) and note the readings.
5. Now take a little sample for your well mixed sample soil and weigh it by using digital weight
machine and preserve the readings.
6. Now leave the Soil to get dry and take the readings of dry soil by using same instrument for
measuring the weight and note down the readings.
Calculations:
W1 = Weight of Container ------------------------------------------------------- 48.86 g
W2 = Weight of Container + Weight of Wet Soil ---------------------------- 360.8 g
W3 = Weight of Container + Weight of Dry Soil----------------------------- 295.46 g
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
360.8−295.46
295.46 −48.86 → 0.264
Water Content is 26.4 %
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 4
Practical#4: To Collect Soil Sample from the Field for Lab Test and Determine Various Properties of Soil.
(B) SAND BATH METHOD
Introduction: This is field method of determining rough value of the water content,
where the facility of an oven is not available.
Apparatus: Container, Kerosene Stove & Weight Machine
Procedure:
1. First of all collect the soil sample from the field, find a soil which should have
a some moisture .
2. Fill about half of the gunny bag and empty it in sample tray.
3. Mix the soil so well so that consolidated particles are turned into soil, don’t
remove any vegetation if any.
4. Using digital weight machine weigh the weight of small bowl (Container) and
note the readings.
5. Now take a little sample for your well mixed sample soil and weigh it by
using digital weight machine and preserve the readings.
6. Now take a sample on Kerosene stove for ½ or 1 Hour till it dries.
7. Weight the Sample and Calculate the water content.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 5
Calculations:
SAMPLE: SL-18
W1 = Weight of Container ------------------------------------------------------- 58.6 g
W2 = Weight of Container + Weight of Wet Soil ---------------------------- 392.10 g
W3 = Weight of Container + Weight of Dry Soil----------------------------- 328.243 g
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
392.10−328.243
328.243−58.6 → 0.244
Water Content is 24.4 %
SAMPLE: D-1
W1 = Weight of Container ------------------------------------------------------- 64.89 g _
W2 = Weight of Container + Weight of Wet Soil ---------------------------- 381.7 g _
W3 = Weight of Container + Weight of Dry Soil----------------------------- 310.78 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
381.7−310.78
310.78−64.89 → 0.288
Water Content is 28.8 %
Precautions: Not suitable for Organic soils or soils having higher percentage of gypsum
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 6
Practical#5: To Collect Soil Sample from the Field for Lab Test and Determine Various Properties of Soil.
(C) Hot Plate
Apparatus: Stove or hot plate, Steel plate(s), approximately ¼” (6.3 mm) thick to place
between the burner(s) and the sample pan, Pan of sufficient size to contain the material and
allow room for stirring without loss of material, Spoon or trowel for stirring the material
during the drying process , Weight Machine.
Procedure:
1. Obtain a sample of wet material weighing a minimum of 100 grams for soils and
a minimum of 500 grams for granular materials.
2. The sample usually has been dried to constant weight, when, using a cool metal
spoon or spatula, the sample is briefly stirred and there is no evidence of moisture
or material sticking to the metal of the stirring instrument.
3. Place the steel plate on the burner of the stove or gas hot plate. Steel plates are
not required on electric hot plates. Place the pan holding the material on the steel
plate.
4. Stir the material during drying to prevent the temperature of the sample from
exceeding 230° ±9°F (110° ±5°C).
5. When you feel it is completely dried , Weigh again and note the water content.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 7
Calculations:
SAMPLE: T-1
W1 = Weight of Container ------------------------------------------------------- 49.51 g_
W2 = Weight of Container + Weight of Wet Soil ----------------------------330.04 g_
W3 = Weight of Container + Weight of Dry Soil----------------------------- 242.84 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
330.04−242.84
242.84−49.51 → Water Content 45.10 %
SAMPLE: A-3
W1 = Weight of Container -------------------------------------------------------47.56 g_
W2 = Weight of Container + Weight of Wet Soil ----------------------------342.74 g_
W3 = Weight of Container + Weight of Dry Soil----------------------------- 220.78 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
342.74−220.78
220.78−47.56 → Water Content is 70.4 %
SAMPLE: YL-005R
W1 = Weight of Container ------------------------------------------------------- 48.19 g_
W2 = Weight of Container + Weight of Wet Soil ----------------------------393.27 g_
W3 = Weight of Container + Weight of Dry Soil----------------------------- 331.88 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
393.27−331.88
331.88−48.19 → Water Content is 21.6 %%
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 8
Practical#6: To determine the Water content by Infrared Lamp.
Apparatus: Soil sample, Infrared lamps
Calculations:
Moisture Content = 102%
Temperature = 100oC
Formula : W = m / 1-m
m = 50 g
W = 10.2 %
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 9
Practical#7: To determine the water content by Calcium Carbide Gas Pressure Moisture Tester Method.
Apparatus: A calcium carbide gas pressure moisture (Speedy) tester, Tared scale, Cleaning
brush, Calcium Carbide reagent, Two 13 g weights, Reagent scoop.
Procedure:
1. Weigh the soil sample by Tared Scale and Place into speedy tester. 2. Now Place 3 scoops of calcium carbide into speedy tester but Place the calcium carbide in
the cap. With the pressure vessel in a horizontal position, insert the cap in the pressure vessel
and tighten the clamp to seal the unit, taking care that no carbide comes in contact with the soil
until a complete seal is achieved.
3. Raise the moisture tester to a vertical position and tap the side of the vessel with the hand so the soil in the cap falls into the pressure vessel and Hold the vessel in a horizontal position and shake. 4. One minute of shaking should be sufficient for granular soils, while 5 minutes or more may be
required for highly plastic soils or shale.
5. Cool the gas. When the needle has STOPPED moving SHAKE
THE “SPEEDY” for at least a half minute, in order to cool the gas
produced. Read the dial while holding the instrument in a
horizontal position at eye level.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 10
Precautions: Point the instrument away from the operator and slowly release the gas pressure, then empty the
contents. When the sample is dumped, it should be examined for lumps. If the sample is not completely broken
down, the test is not valid.
Calculations:
The dial on the moisture tester reads directly in percent moisture by wet
weight. The reading must be converted to percent moisture by dry
weight. The computation is made by using the conversion table which
equates moisture contents by wet weight and dry weight in the normal
range that will be encountered on grading projects, or by using the
following formula:
Formula :
% Moisture by Dry Weight = % Moisture by Wet Weight
1 – (% Moisture by Wet Weight divided by 100)
7.9 =
1 – ( 7.9 divided by 100)
7.9 = 7.9 = 8.577 %
1 - .0.079 .921
See Speedy Conversion Chart On Next Page to Confirm your Results.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 11
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
-
28.9 40.6
29.0 40.8
28.7 40.3
28.8 40.4
28.5 39.9
28.6 40.1
28.3 39.5
28.4 39.7
28.1 39.1
28.2 39.3
27.9 38.7
28.0 38.9
27.7 38.3
27.8 38.5
27.5 37.9
27.6 38.1
27.3 37.6
27.4 37.7
27.1 37.2
27.2 37.4
26.9 36.8
27.0 37.0
26.7 36.4
26.8 36.6
26.5 36.0
26.6 36.2
26.3 35.7
26.4 35.9
26.1 35.3
26.2 35.5
35.025.9
26.0 35.1
25.7 34.6
25.8 34.8
25.5 34.2
25.6 34.4
25.3 33.9
25.4 34.0
25.1 33.5
25.2 33.7
32.8
33.0
33.2
33.3
32.1
32.3
32.4
32.6
31.4
31.6
31.8
31.9
30.7
30.9
31.1
31.2
30.0
30.2
30.4
30.5
29.4
29.5
29.7
29.9
28.7
28.9
29.0
29.2
28.0
28.2
28.4
28.5
27.4
27.6
27.7
27.9
26.7
26.9
27.1
27.2
24.7
24.8
24.9
25.0
24.3
24.4
24.5
24.6
23.9
24.0
24.1
24.2
23.5
23.6
23.7
23.8
23.1
23.2
23.3
23.4
22.2
Speedy Conversion Chart
22.3
22.4
22.5
22.6
22.7
22.8
22.9
23.0
21.8
21.9
22.0
22.1
26.3
26.4
26.6
21.1
21.2
21.3
21.4
21.5
21.6
21.7
25.6
25.8
25.9
26.1
25.0
25.2
25.3
25.5
24.4
24.5
24.7
24.8
23.8
23.9
24.1
24.2
23.2
23.3
23.5
23.6
22.5
22.7
22.8
23.0
22.0
22.1
22.2
22.4
20.9
21.0
20.8
20.9
21.1
21.2
21.4
21.5
21.7
21.8
20.5
20.6
20.7
20.8
20.1
20.2
20.3
20.4
19.7
19.8
19.9
20.0
19.3
19.4
19.5
19.6
18.9
19.0
19.1
19.2
18.5
18.6
18.7
18.8
18.1
18.2
18.3
18.4
20.6
17.2
17.3
17.4
20.2
20.3
20.5
17.1
17.5
17.6
17.7
17.8
17.9
18.0
19.6
19.8
19.9
20.0
19.0
19.2
19.3
19.5
18.5
18.6
18.8
18.9
17.9
18.1
18.2
18.3
17.4
17.5
17.6
17.8
16.8
17.0
17.1
17.2
16.3
16.4
16.6
16.7
16.9
17.0
15.2
15.3
15.5
15.6
15.7
15.9
16.0
16.2
16.5
16.6
16.7
16.8
16.1
16.2
16.3
16.4
15.7
15.8
15.9
16.0
15.3
15.4
15.5
15.6
14.9
15.0
15.1
15.2
14.5
14.6
14.7
14.8
14.1
14.2
14.3
14.4
13.7
13.8
13.9
14.0
13.3
13.4
13.5
13.6
13.1 15.1
13.2
13.0 14.9
12.8 14.7
12.9 14.8
12.6
12.7
14.4
14.5
12.4 14.2
12.5 14.3
13.8
13.9
12.3 14.0
12.1
12.2
12.7
12.9
13.0
13.1
13.2
13.4
13.5
13.6
11.7
11.8
11.9
12.0
11.3
11.4
11.5
11.6
11.1 12.5
11.2 12.6
10.9 12.2
11.0 12.4
10.7 12.0
10.8 12.1
10.5 11.7
10.6 11.9
10.3 11.5
10.4 11.6
10.1
10.2
10.5
10.6
10.7
10.9
11.0
11.1
11.2
11.4
9.1
9.2
9.3
9.4
Pe
rce
nt
Mo
istu
re
Dry
We
igh
t
Sp
ee
dy
Re
ad
ing
Pe
rce
nt
Mo
istu
re
Dry
We
igh
t
Sp
ee
dy
Re
ad
ing
10.1
10.2
10.4
9.5
9.6
9.7
9.8
9.9
10.0
8.8
8.9
9.0
9.2
9.3
9.4
9.5
9.6
9.8
9.9
8.4
8.5
8.6
8.7
8.2 8.9
8.3 9.0
8.0 8.7
8.1 8.8
7.8 8.4
7.9 8.6
7.6 8.2
7.7 8.3
7.4 8.0
7.5 8.1
7.2 7.8
7.3 7.9
7.0 7.5
7.1 7.6
6.8 7.3
6.9 7.4
6.6 7.1
6.7 7.2
6.4 6.8
6.5 7.0
6.2 6.6
6.3 6.7
6.0 6.4
6.1 6.5S
pe
ed
y R
ea
din
g
Pe
rce
nt
Mo
istu
re
Dry
We
igh
t
10.0P
erc
en
t M
ois
ture
Dry
We
igh
t
Sp
ee
dy
Re
ad
ing
Sp
ee
dy
Re
ad
ing
Pe
rce
nt
Mo
istu
re
Dry
We
igh
t5.8 6.2
5.9 6.3
5.6 5.9
5.7 6.0
5.4 5.7
5.5 5.8
5.2 5.5
5.3 5.6
5.0
5.1
Sp
ee
dy
Re
ad
ing
5.3
Pe
rce
nt
Mo
istu
re
Dry
We
igh
t
5.4
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 12
Practical#8: To determine specific gravity of soil sample utilizing density bottle method by Vacuum Pressure
6-9-11
Theory:
The Specific gravity of solid particles is the ratio of the mass density of solids to that water. It is
determined in the laboratory using the relation:
Where ,
M1 = Mass of Empty Bottle
M2 = Mass of the bottle and Dry Soil
M3 = Mass of bottle , Soil and Water
M4 = Mass of bottle filled with water only.
Apparatus: 50 ml Density bottle with stopper, Oven , Vacuum pump, Weighing balance and
Spatula.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 13
Procedure:
1. Wash the Density bottle and dry it in oven at 1000c and weigh the bottle (M1)
2. Take 5 to 10 g of oven dried soil and transfer it to density bottle , weigh the bottle with stopper
and dry sample (M2)
3. Add Distilled water to the density bottle to cove the soil, and shake gently to mix the soil and
water.
4. Evacuate the desiccator gradually by operating the vacuum pump, reduce the pressure to about
20mm of mercury.
5. Replace the vacuum and remove the lid of the desiccator . Stir the soil in the bottle carefully
with a spatula from the bottle , the particles adhering to it should be washed off with few drops
of distilled water. Replace the lid of the desiccator again and apply vacuum until no more air is
evolved from specimen .
6. After that determine the mass of bottle and its contents ( M3)
7. Empty the bottle and fill it with distilled water and weigh it (M4)
Observations:
Sr.
No.
M1
(Mass of
empty
density
bottle.)
M2
(Mass of
density
bottle + Soil
grains)
M3
(Mass of empty
density bottle +
Soil grains +
water)
M4
(Mass of empty
density bottle +
water.)
Specific Gravity
G
= (𝑀2 − 𝑀1 )
(𝑀2 −𝑀1) − (𝑀3−𝑀4)
1 176.97 g 276.97 g 732.96 g 673.94 12.127
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 14
Practical # 9 : To Find the liquid limit by Using Casagrande Method.
Theory:
The liquid limit is determined from a apparatus that consists of a Semispherical brass cup that is
repeatedly dropped onto a hard rubber base from a height of 10mm by a Cam-operated mechanism.
The Apparatus was developed by A.Casagrande (1932) .
Apparatus: Casagrande Device , Soil Sample and Grooving Tool.
Procedure:
1. A dry powder of sample soil is mixed with distilled water into a paste and placed in a cup to
thickness of about 12.5 mm.
2. The Soil surface is smoothed and a groove is cut into soil using standard grooving tool.
3. The crank operating the cam is turned at a rate of 2 revolutions per second and the number of
blows required to close the groove over a length of 12.5 mm is counted and recorded.
4. The Soil within the closed portion is extracted for determination of the water content.
5. The liquid limit is defined as the water content at which the groove cut into the soil will close
over a distance of 12.5 mm following 25 blows
6. Four or more tests at different water contents are performed to get Terminal blows ( no. of
blows to close the grove over a distance of 12.5 mm)
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 15
For Fine Grained Soil For Fine Grained having Sand Content
Observations:
Sample No. of Blows
W1 (g) W2(g) W3(g) Water Content (%)
SL-46 45 46.95 70.84 51.36 20.17
B-9 33 49.90 85.96 81.67 20.60 D-10 18 30.9 81.67 76.14 22.09
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 16
From Above Graph we can examine the Liquid limit is 20%
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 17
Practical # 10 : To Find the liquid limit by Using Fall Cone Method.
Theory:
The Fall cone test apparatus is an alternative method to the Casagrande Device in measuring the Liquid
Limit of a soil sample.
Procedure:
1. In a fall cone test, a cone with a apex angle of 300 and total mass of 80 grams( 0.78 N) is
suspended.
2. The cone is permitted to fall freely for a period for 5 seconds
3. The water content corresponding to a cone penetration of 20mm defines the liquid limit.
4. The sample preparation is similar to cup method except that that the sample container in the
fall cone test has a different shape and size
5. Four or more tests at different water contents are also required because of the difficulty of
achieving the liquid limit from a single test.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 18
SAMPLE: BL-005
W1 = Weight of Container -------------------------------------------------------34.96 g_
W2 = Weight of Container + Weight of Wet Soil ----------------------------109.32 g_
W3 = Weight of Container + Weight of Dry Soil----------------------------- 87.61 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
109.32−87.61
87.61−34.96 → Water Content is 41.2 %
SAMPLE: SL-95
W1 = Weight of Container -------------------------------------------------------37.12 g_
W2 = Weight of Container + Weight of Wet Soil ----------------------------109.44 g_
W3 = Weight of Container + Weight of Dry Soil----------------------------- 86.88 g_
Formula = 𝑊2−𝑊3
𝑊3− 𝑊1 * 100 →
109.44−86.88
86.88−37.12 → Water Content is 45.33 %
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 19
Penetration ( mm) Water Content ( % )
18 41.2
26.5 45.33
Making a semi-logarithm graph will help us to find liquid limit. So, from above Graph.
Liquid Limit = 42 %
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 20
Practical # 11 : To Find the Plastic limit by Utilizing glass plate.
Apparatus: Spatula, glass plate and balance.
Procedure:
1. From the 20g sample select a 1.5 to 2 g specimen for testing.
2. Roll the test specimen between the palm or fingers on the ground glass plate to from a thread of uniform diameter.
3. Continue rolling the thread until it reaches a uniform diameter of 3.2mm or 1/8 in.
4. When the thread becomes a diameter of 1/8 in. reform it into a ball.
5. Knead the soil for a few minutes to reduce its water content slightly.
6. Repeat steps 2 to 5 until the thread crumbles when it reaches a uniform diameter of 1/8 in.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 21
7. When the soil reaches the point where it will crumble, and when the thread is a uniform diameter of 1/8", it is at its plastic limit. Determine the water content of the soil.
Observations:
Container W1 (g) W2 (g) W3 (g) WL (%) Average
Bl-5 7.78 16.39 15.28 14.8 Plastic
Limit (PL)
= 15%
C-7 7.83 13.43 12.69 15.2
D-66 15.16 21.23 20.43 15.1
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 22
Practical # 12 : Sieve Analysis
This test is performed to determine the percentage of different grain sizes contained within a soil. The mechanical or sieve analysis is performed to determine the distribution of the coarser, larger-sized particles.
Apparatus: Balance, Set of sieves, Cleaning brush, Sieve shaker
Procedure:
1. Obtain the mass of soil retained on each sieve by subtracting the weight of the empty sieve from the mass of the sieve + retained soil, and record this mass as the weight retained on the data sheet. The sum of these retained masses should be approximately equals the initial mass of the soil sample. A loss of more than two percent is unsatisfactory. 2- Calculate the percent retained on each sieve by dividing the weight retained on each sieve by the original sample mass. 3- Calculate the percent passing (or percent finer) by starting with 100 percent and subtracting the percent retained on each sieve as a cumulative procedure. For example: Total mass = 500 g Mass retained on No. 4 sieve = 9.7 g
Mass retained on No. 10 sieve = 39.5 g For the No.4 sieve: Quantity passing = Total mass - Mass retained = 500 - 9.7 = 490.3 g The percent retained is calculated as; % retained = Mass retained/Total mass = (9.7/500) X 100 = 1.9 % From this, the % passing = 100 - 1.9 = 98.1 % For the No. 10 sieve: Quantity passing = Mass arriving - Mass retained = 490.3 - 39.5 = 450.8 g % Retained = (39.5/500) X 100 = 7.9 % % Passing = 100 - 1.9 - 7.9 = 90.2 % (Alternatively, use % passing = % Arriving - % Retained For No. 10 sieve = 98.1 - 7.9 = 90.2 %)
4- Make a semilogarithmic plot of grain size vs. percent finer.
5- Compute Cc and Cu for the soil.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 23
S.No Size Opening Retained Cumulative % Passing %
3 75 mm Nil 3605 0 100
2.5 64 mm Nil 3605 0 100
2 50 mm Nil 3605 0 100
1 25 mm 2.917 3602.08 0.08 99.9
¾ 19 mm 43.04 3559.04 1.19 98.73
1.5 37.5 mm Nil 3559.04 0 98.73
0.5 12.7 mm 65.64 3493.4 1.820 96.91
3/8 9.5 mm 115.64 3377.6 3.20 93.71
#4 4.75 mm 347.38 3030.22 9.63 84.08
#10 2 mm 730.1 2300.12 20.25 63.83
#40 425 Micron 901.50 1398.62 25 38.83
#100 750 Micron 950.37 448.25 26.36 12.47
#200 0.75 Micron 8.57 439.68 0.229 12.24
Pan - 439.84 0 12.20 0
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 24
Observations:
% Gravel = 9.54 %
% Sand = 78.26 %
% Fine = 12.2 %
D10 = 3 micron
D30 = 95 Micron
D60 = 1000 Micron
C u = 𝐷60
𝐷10 → 333.33
C c = (𝐷30) 2
𝐷60∗𝐷10 → 3.08
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 25
Practical # 13 : To determine the particle size analysis by Hydrometer Analysis.
Theory:
This test is performed to determine the percentage of different grain sizes contained within a soil. The
mechanical or sieve analysis is performed to determine the distribution of the coarser, larger-sized
particles, and the hydrometer method is used to determine the distribution of the finer particle
Apparatus:
Hydrometer, Measuring cylinder , balance , pipette , sodium Hexametaphosphate
Procedure:
1. Prepare the dispersing solution by mixing 40 g of Sodium Hexametaphosphate in 1 Litre of
distilled water. Stir or shake until the dispersing agent has all dissolved.
2. Weigh 50 g of dried, sieved soil and pour it into beaker. Add 100 mL of the dispersing solution
and about 50 mL of distilled water to the beaker. Stir vigorously with a spoon or sitrring rod for
at least one minute. Be sure the soil is thoroughly mixed and does not stick to the bottom of the
beaker. Do not let any of the soil suspension spill out the top.
3. Stir the suspension in the beaker again, and pour it into a 500 mL graduated cylinder. Use a
squirt bottle to rinse out the beaker and add this to the soil mixture in the cylinder
4. Mix vigorously by rotating the covered cylinder hand-over-hand at least 10 times. Be sure the
soil is thoroughly mixed in the solution and does not stick to the bottom of the cylinder. Try not
to let any of the suspension leak out the top.
5. Gently set the cylinder down in a safe place, and immediately begin timing with a stop watch or
clock with a second hand.
6. After 1 minute, carefully lower the hydrometer into the cylinder so it floats in the suspension.
Steady the hydrometer to keep it from bobbing up and down.
7. At exactly 2 minutes after the cylinder was set down, read the line on the hydrometer that is
closest to the surface of the soil suspension and record your result on the Particle-Size
Distribution Data Work Sheet.
8. Take Readings on 4,8,16,30,60 min .
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 26
Hydrometer Analysis
Test Date: 10/10/11
Tested By: 09CE (A)
Hydrometer Number (if known): 152 H
Specific Gravity of Solids: 2.55
Dispersing Agent: Sodium Hexametaphosphate
Weight of Soil Sample: 50 gm
Zero Correction: +3
Meniscus Correction: +1
Date Time (min)
Temp 0C
Actual Hydg. Reading Ra
Hyd. Corr for Meniscus
L from Table 1
D mm
K from Table 2
CT from Table 3
a from table 4
Corr. Hyd. Rdg. Rc
% finer P
% Adjusted Finer
10/10/11
1 20 33 34 10.7 0.04533 0.01386 0.00 1.02 30 61.2 7.49
2 20 31 32 11.1 0.03265 0.01386 0.00 1.02 28 57.12 6.99
4 20 29 30 11.4 0.02339 0.01386 0.00 1.02 26 53.04 6.48
8 20 26 27 11.9 0.02061 0.01386 0.00 1.02 26 53.04 6.49
16 20 24 25 12.2 0.01210 0.01386 0.00 1.02 21 42.84 5.24
30 20 20 21 12.9 0.00908 0.01386 0.00 1.02 17 34.68 4.24
60 21 13 14 14.0 0.00661 0.01369 +0.20 1.02 10 20.4 2.44
D = K 𝐿
𝑡
Where t is in minutes, and D is given in m
Rc = Ra - zero correction + CT
P = ( Rc * a / Ws ) * 100
Where Ws is the weight of the soil sample in grams
Pa = P * F200 / 100
Where F200 is the % finer sieve as a percent
Tables on Next Pages
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 27
Contributing Results from Sieve Analysis and from Hydrometer , constituting a new graph.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 28
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 29
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 30
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 31
Practical # 14 : To determine the co-efficient of Permeability
Theory:
The purpose of this test is to determine the permeability (hydraulic conductivity) of a sandy soil by the
constant head test method. There are two general types of permeability test methods that are routinely
performed in the laboratory: (1) the constant head test method, and (2) the falling head test method.
The constant head test method is used for permeable soils (k>10-4 cm/s) and the falling head test is
mainly used for less permeable soils k<10-4 cm/s)
Apparatus:
Permeameter, Tamper, Balance, Scoop, 1000 mL Graduated cylinders, Watch (or Stopwatch),
Thermometer, Filter paper
Procedure:
(1) Measure the initial mass of the pan along with the dry soil (M1).
(2) Remove the cap and upper chamber of the permeameter by unscrewing the knurled cap nuts and
lifting them off the tie rods. Measure the inside diameter of upper and lower chambers. Calculate
the average inside diameter of the permeameter (D).
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 32
3. Mix the soil with a sufficient quantity of distilled water to prevent the segregation of particle sizes
during placement into the permeameter. Enough water should be added so that the mixture may flow
freely
4.Use the tamping device to compact the layer of soil. Use approximately ten rams of the tamper per
layer and provide uniform coverage of the soil surface. Repeat the compaction procedure until
the soil is within 2 cm. of the top of the lower chamber section
5.Replace the upper chamber section, and don’t forget the rubber gasket that goes between the
chamber sections. Be careful not to disturb the soil that has already been compacted
6. Secure the cap firmly with the cap nuts.
7. Connect the flexible tube from the tail of the funnel to the bottom outlet of the permeameter and
keep the valves on the top of the permeameter operator
8. Open Upper exit to sink to collect any water that may come out.
9. As soon as the water begins to flow out of the top control valve, close the control valve, letting water
flow out of the outlet for some time & Allow adequate time for the flow pattern to stabilize
10. Measure the time it takes to fill a volume of 750 - 1000 mL using the graduated cylinder, and then
measure the temperature of the water. Repeat this process three times and compute the average time,
average volume, and average temperature. Record the values as t, Q, and T, respectively
11. Measure the vertical distance between the funnel head level and the chamber outflow level, and
record the distance as h.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 33
Observations:
H1 =
H2 =
t =
Q =
a=
A =
L =
Calculations:
𝐾 = 𝑎 𝐿𝑛
𝐻1𝐻2
∗ 𝐿
𝐴 ∗ 𝑡
=
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 34
Practical # 15: To determine Consolidation Test.
Theory:
This test is performed to determine the magnitude and rate of volume decrease that a laterally confined
soil specimen undergoes when subjected to different vertical pressures.
Equipments:
Consolidation device (including ring, porous stones, water reservoir, and load plate), Dial gauge (0.0001 inch = 1.0 on dial), Sample trimming device, glass plate, Metal straight edge, Clock, Moisture can, Filter paper.
Procedure:
1. Weigh the empty consolidation ring together with glass plate.
2. Measure the height (h) of the ring and its inside diameter (d).
3. approximately a three-inch long sample. Place the sample on the consolidation ring and cut the sides of the sample to be approximately the same as the outside diameter of the ring.
4. Turn the ring over carefully and remove the portion of the soil protruding above the ring. Using the metal straight edge, cut the soil surface flush with the surface of the ring. Remove the final portion with extreme care.
Soil Mechanics Sir Dr.Aneel Kumar
Darya Memon – 09CE37 35
5. Weigh the specimen plus ring plus glass plate.
6. Being careful to prevent movement of the ring and porous stones, place the load plate centrally on the upper porous stone and adjust the loading device.
7. Adjust the dial gauge to a zero reading.
8. Fill the apparatus full of water. As we need Fully saturated Soil.
9. Record the consolidation dial readings
Calculations:
Weight of Wet Soil + Ring = 257.04 g Weight of Ring = 969 g Diameter of Ring = 7.575 Area of Ring = π / 4 * 7.575 → 45.043 cm2 → 45.043 / 10 → 4.5 cm2 4.5 * 0.25 → 1.126 kg
Time - Settlement Data (1 unit on dial guage = 0.0001 inches)
Loading = 2.256 kg, Initial Reading 10 mm
Time Dial Reading
0.5 min 9.61 mm
1 min 9.05 mm
2 min 9.595 mm
4 min 9.59 mm
Loading = 1.26 kg, Initial Reading 10 mm
Time Dial Reading
0.5 min 9.84 mm
1 min 9.83 mm
2 min 9.82 mm
4 min 9.815 mm