This document provides details of laboratory experiments conducted to determine various properties of soil, including: 1. The dry density of soil in situ using the sand replacement method. Testing yielded a dry density of 1.79 g/cm3. 2. The maximum dry density and optimum moisture content of soil through dynamic compaction, which were determined to be 1.85 g/cm3 and 11% respectively. 3. Particle size distribution through a hydrometer analysis, with procedures and apparatus described.

1. UNIVERSITY OF NAIROBI
FCE 311
GEOTECHNICAL ENGINEERING
SOIL MECHANICS LABORATORY
F16/1585/2015
SAKWA IGNATIUS SHIUNDU
20TH
NOVEMBER, 2016

2. F16/1585/2015
1
DETERMINATION OF THE DRY DENSITY OF SOIL IN SITU
SAND REPLACEMENT METHOD
SCOPE
This method covers the in situ determination of the dry density of natural or compacted soil. The
method is applicable to soils containing not less than 90% passing the 1’ (25mm) sieve, and
compacted layers not exceeding 20cm (8’) thickness.
PRINCIPLE OF METHOD
The method is based on excavating a round hole in the soil stratum, weighing the amount of soil
excavated, and measuring the volume of the hole by filling it with calibrated dry sand.
The dry density of the soil is found as the dry weight of the excavated soil divided by the volume
of the hole that was occupied by that soil.
APPARATUS
1) A pouring cylinder incorporating a shutter and a cone.
2) A calibrating can of size corresponding to ‘1)’, i.e. for the medium size 6in. (15cm) diameter
and 8in. (20cm) deep.
3) Suitable tools for excavating holes in the soil e.g. bent spoon, dibber, chisel or other hand tools.
4) A balance, readable and accurate to 1g.
5) A glass plate about 20in. (50cm) square and 3
/8in. (9mm) thick or any plane smooth surface of
this size or larger.
6) A metal tray 12in. (30cm) square and 11
/2in. (4cm) deep, with a 6in. (15cm) diameter hole in
the middle for the medium size equipment.
7) Metal containers with a lid to take excavated soil. The same container may or may not be used
for drying the soil.
8) A drying oven capable of maintaining a temperature of 105°–110°C.

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MATERIAL
Clean uniform natural sand, e.g. material passing B.S sieve no. 25 and retained on B.S sieve no.
52. This should have been oven-dried and stored to allow its moisture content to reach equilibrium
with atmospheric humidity.
CALIBRATION OF APPARATUS
The pouring cylinder was filled with the prepared sand and weighed. This total initial weight was
maintained throughout the tests for which the calibration was used.
The pouring cylinder was placed on a glass plate and the shutter opened allowing sand to run out.
Flapping or vibrating of the cylinder was avoided. When no further movement of sand took place
in the cylinder, the shutter was closed and the cylinder removed carefully.
The amount of sand that had filled the cone was weighed. This was repeated thrice and the mean
mass (W2) recorded.
BULK DENSITY OF SAND
The volume (V) of the calibration can was determined by weighing the amount of water required
to fill it exactly to the brim.
The pouring cylinder was filled to the predetermined mass (W1) and placed concentrically atop the
calibrating can. The shutter was opened, allowing the sand to run out, but tapping or vibrating the
pouring cylinder was avoided. When no further movement of sand took place, the shutter was
closed, and the cylinder removed and weighed. This measurement was repeated three times and
the mean mass (W3) recorded.
MEASUREMENT OF SOIL DENSITY
A flat area of the soil to be tested was exposed, about 18in. (45cm), and trimmed down to a level
surface.
The metal tray was placed on the prepared surface and, using the hole in the tray as a pattern, a
hole in the soil was excavated about 6in. (15cm) diameter and up to a maximum of 8in. (20cm)
deep (These dimensions depend on the size of the apparatus). No loose material was left in the
hole. All excavated soil was carefully collected in the container, keeping it closed between fillings.
The tray was removed and any spillage of soil collected.

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The pouring cylinder filled to the predetermined mass (W1) was placed to cover the hole
concentrically. The shutter was opened allowing sand to run out, tapping or vibrating the cylinder
was avoided. When no further movement of sand took place, the shutter was closed and the
cylinder removed.
The pouring cylinder was weighed (W4). The excavated soil sample was weighed (WE) and the
moisture content (m) determined by oven-drying preferably the whole sample or otherwise a
representative part of it, using a container of known mass (WC).
The measurement was repeated at a number of different points of the site to obtain a representative
average density.
RESULTS DATE: 15/11/2016
Calibrations
Weight of sand filled cylinder (constant), (W1) = 7000g
Mass of sand in cone(W2) = 1270g
Bulk density of sand (PS = WA/VA) = 1.3 ; where VA is the volume of calibrating can.
Soil density determinations
MASS OF CYLINDER AFTER POURING IN HOLE (W4) = 2200g
MASS OF SAND POURED IN HOLE AND CONE (W1 –
W4)
= 4800g
MASS OF SAND TO FILL HOLE (WB = W1 –W4 – W2) = 3530g
VOLUME OF HOLE VB =
WB
PS
= 2715.4cm3
MASS OF WET EXCAVATED SOIL (WE) = 5100g
CONTAINER NO. = 55B
MASS OF DRYING CONTAINER + WET SAMPLE (W6) = 331g
MASS OF DRYING CONTAINER + DRY SAMPLE (W7) = 319.2g
LOSS OF WEIGHT IN DRYING SAMPLE (W6 – W7) = 11.8g
MASS OF DRYING CONTAINER (W’C) = 76g
MASS OF DRY SAMPLE (W7 – W’C) = 243.2g
MOISTURE CONTENT, M =
W6− W7
W7− W′C
= 4.85%
BULK DENSITY OF SOIL, P =
WE
VB
= 1.88g/cm3
DRY DENSITY OF SOIL, PD =
P
1+M
= 1.79g/cm3

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DYNAMIC COMPACTION USING A 2.5 KG RAMMER
SCOPE
This method covers the determination of dry density of soil when compacted over a range of
moisture contents. The method is applicable to soils containing not less than about 90% passing
the 3
/4in. (19mm) B.S. Sieve.
PRINCIPLE OF METHOD
The method is based on a series of tests, each of which includes compacting the soil at different
moisture content into a specified mould by means of a rammer. The dry density of the soil is plotted
as a function of the moisture content and a Maximum Dry Density as well as Optimum Moisture
Content determined.
APPARATUS
1) A metal mould with a detachable base plate and a removable collar.
2) A metal rammer weighing 2.5 kg with sleeve to control the specified drop of 30.5 cm.
3) A 3
/4 in. (19mm) B.S. sieve and metal trays.
4) A balance, hand tools and straightedge.
5) A sample extruder, oven and moisture content dishes.
6) Measuring cylinder and water.
PROCEDURE
1) An air-dry sample was prepared to provide about 20 kg of soil passing the 3
/4 in. (19cm) B.S.
Sieve and weigh six sub-samples each weighing about 3kg.
2) The samples were mixed with different amounts of water tom give a suitable range of moisture
content. The increment of water from one sub-sample to the next should be 1–2% or 2–4%.
3) The mould was weighed with the base-plate, W1, and the collar attached.
4) Each sub-sample was compacted into the mould in 3 layers of equal weight, each layer being
given 25 blows from the rammer dropped above the soil.
5) The collar was removed and excess soil trimmed off. The mould, base plate and soil specimen
contained were weighed.

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6) The specimen was extruded from the mould and a representative part of the specimen taken
for moisture content (M) determination. The same was repeated for the rest of the sub-samples.
RESULTS DATE: 15/11/2016
Weight of air-dried sample = 3 kg
Volume of mould, V =
𝜋𝐷2𝐻
4
= 956 cm3
No. of layers: 3 No. of blows per layer: 25
TEST NUMBER
1 2 3 4
WATER ADDED IN cm3 100 200 300 400
WEIGHT OF MOULD + SPECIMEN, W1 (g)
6248 6430 6400 6300
WEIGHT OF MOULD, W2 (g)
4470 4470 4470 4470
WEIGHT OF SPECIMEN, W = W1 – W2 (g)
1778 1960 1930 1830
BULK DENSITY OF SPECIMEN, P = W/V (g/cm3
)
1.86 2.05 2.02 1.91
DRYING DISH NO.
37 13 31 57
WEIGHT OF DRYING DISH + WET SPECIMEN, W3 (g)
253.6 212.0 311.2 332
WEIGHT OF DRYING DISH + DRY SPECIMEN, W4 (g)
242.2 198.7 283.1 296.3
WEIGHT OF DRYING DISH, W5 (g)
78.9 76.0 78.9 77.4
LOSS OF WEIGHT IN DRYING, W3 – W4 (g)
11.4 13.3 28.1 35.7
WEIGHT OF DRY SPECIMEN, W4 – W5 (g)
163.3 122.7 204.2 218.9
MOISTURE CONTENT, M (%)
6.98 10.8 13.8 16.3
DRY DENSITY OF SPECIMEN, PD =
P
1+M
(g/cm3
) 1.74 1.85 1.78 1.64

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From the graph, MDD = 1.85 g/cm3
OMC ≃ 11 %
6.98, 1.74
10.8, 1.85
13.8, 1.78
16.3, 1.64
1.6
1.65
1.7
1.75
1.8
1.85
1.9
0 2 4 6 8 10 12 14 16 18
Dry
Density
(g/cm
3
)
Moisture Content (%)
Compaction Curve

8. F16/1585/2015
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HYDROMETER ANALYSIS
SUBSIDIARY METHOD FOR FINE-GRAINED SOILS (HYDROMETER METHOD)
This method covers the quantitative determination of particle size distribution in a soil sample
from coarse sand size down. The test as described is not applicable if less than 10% of the material
passes the 63µm BS test sieve.
APPARATUS
1) A hydrometer fulfilling the following requirements of BS 718.
The bulb and stem was made of glass as free as possible from visible defects. The glass was
resistant to chemical elements and shall be well annealed.
Where a solid loading material was used, it was fixed in the bottom part of the hydrometer by
means of aa cementing material which did not soften when heated to 80°C. Where mercury
was the loading material, it was confined to the bottom part of the hydrometer.
The scale inscriptions were marked clearly in permanent black ink on high quality paper having
a smooth surface i.e. an esparto paper (65% to 75% esparto), the strips cut in the machine
direction of the paper.
The stem and bulb were circular in cross section shall be symmetrical about the main axis.
There were no abrupt changes in cross section such as would hinder cleaning or drying, or
permit air bubbles to be trapped. The hydrometer always floated, at all points within its range,
with the stem within 11
/2° of the vertical.
The graduation lines were fine, distinct and of uniform thickness, and showed no evident
irregularities in spacing. The scale was straight and without twist, with the graduation lines at
right angles to the axis of the vertical.
The graduation lines were at intervals of 0.0005, every alternate line extending beyond the
shortest lines, every tenth graduation exceeding that of all intervening lines and numbered in
full.
The basis of the scale was density (g/ml) and calibrated to read 1.000 at 20°C.
The adjustment of the hydrometer was related to a liquid having a surface tension of 55 mN/m.
The maximum permissible scale error the hydrometer was ± 1 scale division.
The following inscriptions were marked legibly within the stem or bulb of each hydrometer
and did not encroach on the scale or figuring.

9. F16/1585/2015
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i. The basis of scale i.e. g/ml at 20°C.
ii. The maker’s or vendor’s name or mark.
iii. An identification number.
iv. The number of this British Standard i.e. BS 1377.
2) Two 1000ml graduated glass measuring cylinders with parallel sides or two parallel-sided glass
cylinders with ground glass stoppers about 70 mm diameter and 330 mm high marked at
1000ml volume.
3) A thermometer to cover the temperature range 0°C to 50°C, readable and accurate to 0.5°C.
4) A mechanical shaker capable of keeping 75 g of soil and 150 ml water in continuous
suspension.
5) BS test sieves 2 mm, 600 µm,212 µm, 63 µm and a receiver.
6) A balance readable and accurate to 0.01 g.
7) A thermostatically controlled drying oven, capable of maintaining temperatures of 105°C to
110°C.
8) A stop watch.
9) A desiccator (200 mm to 250mm diameter) containing anhydrous silica gel.
10) A millimetre scale.
11) Four porcelain evaporating dishes (about 150 mm diameter).
12) A wide-mouthed conical flask or beaker of 1000 ml capacity.
13) A centrifuge capable of holding 250 ml capacity bottles.
14) 250 ml polypropylene centrifuge bottles.
15) A 100 ml measuring cylinder.
16) A wash bottle, preferably plastic, containing distilled water.
17) A length of glass rod about 150 mm to 200mm long and 5 mm in diameter.
18) A constant temperature bath or cabinet large enough to take the apparatus used in this test. The
bath did not vibrate the sample.

10. F16/1585/2015
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REAGENTS
The following reagents were required, and were of recognized analytical reagent quality.
1) Hydrogen peroxide. A 20 volume solution.
2) Sodium hexametaphosphate solution. 33 g of sodium hexametaphosphate solution and 7 g of
sodium carbonate were dissolved in distilled water to make 1 litre of solution. This solution is
unstable and was freshly prepared approximately once a month. The preparation date was
recorded on the bottle.
MENISCUS CORRECTION
1) The hydrometer was inserted in a 1000 ml measuring cylinder containing about 700 ml of
water.
2) By placing the eye slightly below the plane of the surface of the liquid and the raising it slowly
until the surface, seen as an ellipse, becomes a straight line, the point where the plane
intersected the hydrometer scale was determined.
3) By placing the eye slightly above the plane of the surface of the liquid, the point where the
upper limit of the meniscus intersected the hydrometer was determined.
4) The difference between the two readings taken above was recorded as the meniscus correction,
Cm.
PROCEDURE
Pre-treatment of soil
1) A sample of air-dried soil weighing approximately 75 g was obtained by riffling from the air-
dried bulk sample obtained as described in the procedure for preparation of disturbed samples
for testing. The soil, the mass of which need not be known accurately at this stage, was placed
in the wide-mouthed conical flask. 150 ml of hydrogen peroxide was then added and the
mixture stirred gently with a glass rod for a few minutes, after which it was covered with a
cover glass and left to stand overnight. The mixture in the conical flask was heated gently. As
soon as the vigorous frothing had subsided, the volume was reduced to about 50 ml by boiling.
With very organic soils, additional peroxide may be required to complete oxidation.
2) The centrifuge bottle with its stopper was weighed accurately to the nearest 0.001 g and the
contents of the beaker transferred to the centrifuge bottle, taking care not to lose any soil in the

11. F16/1585/2015
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transfer. The volume of water in the bottle was adjusted to about 200 ml, the bottle stoppered
and centrifuged for 15 minutes at about 2000 rev/min. The clear supernatant liquid was
decanted and the bottle and its contents placed in the oven and allowed to dry overnight. The
bottle was re-stoppered and allowed to cool in a desiccator. Once cool, the bottle was
reweighed and the mass of oven-dry pre-treated soil (m) calculated.
Dispersion of soil
1) 100 ml of sodium hexametaphosphate solution was added from a pipette to the soil in the
centrifuge bottle and the mixture shaken thoroughly until all the soil was in suspension. The
centrifuge tube was shaken in the mechanical shaking device for at least 4 hours or overnight.
2) The suspension was transferred from the centrifuge bottle to the 63 µm BS test sieve placed
on the receiver, and soil washed in the sieve using a jet of distilled water from the wash bottle.
The amount of water used during this operation did not exceed 500 ml. The suspension that
had passed through the sieve was transferred to the 1000 ml measuring cylinder and made up
to exactly 1000 ml with distilled water. This suspension was then used for the sedimentation
analysis.
3) The material retained on the 63 µm BS test sieve was transferred to an evaporating dish and
dried in the oven maintained at 105°C to 110°C. After drying, this material was re-sieved on
the 2mm, 600 µm, 212 µm and 63 µm BS test sieves. The material retained on these sieves
after the second sieving was weighed and the masses recorded as the mass of gravel, coarse,
medium and fine sand respectively in the sample (mg, mcs, mms and mfs).
Sedimentation
1) A rubber bung was inserted in the mouth of the measuring cylinder. The measuring cylinder
was then shaken vigorously until a uniform suspension was formed and finally inverted end-
over-end. Immediately the shaking had ceased, the measuring cylinder was allowed to stand
and the stop watch started. The hydrometer was immersed to a depth slightly below its floating
position and then allowed to float freely. The hydrometer readings were taken for periods of
11
/2 min, 1 min, 2 min and 4 min. The hydrometer was then removed slowly, rinsed in distilled
water and kept in a cylinder of distilled water of the same temperature as the soil suspension.

12. F16/1585/2015
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2) The hydrometer was reinserted in the suspension and readings taken after periods of 8 min, 15
min, 39 min, 1 h, 2 h and 4 h after the shaking. The hydrometer was removed, rinsed and placed
in the distilled water after each reading. After 4 h, sedimentation readings were taken once or
twice daily, the exact period of sedimentation being noted. In taking all readings, insertion and
withdrawal of the hydrometer before and after taking a reading was done carefully to avoid
disturbing the suspension unnecessarily. Ten seconds were allowed for each operation;
vibration of the sample being avoided.
3) The temperature of the suspension was observed and recorded once during the first 15 min and
then after every subsequent reading. The temperature was read with an accuracy of at least ±
0.5°C.
4) The correction, x, to be applied for the dispersing agent was ascertained by placing exactly 50
ml of the dispersing agent solution in a weighed glass weighing bottle. After evaporating the
water by drying at 105°C to 110°C in the oven, the mass of the dispersing agent, md, was
calculated.
The dispersing agent correction, x, was calculated from the equation:
x = 2md
This correction is independent of the temperature and should be approximately 4 if the
concentration of the sodium hexametaphosphate is that recommended in 2.7.4.3(2).
CALCULATIONS
Fine sieving:
The mass of the pre-treated soil, m, in grams was used to calculated the calculate the percentages
which follow.
1) The percentage of gravel in the original sample was calculated from the following equation:
Percentage gravel (2.0 mm) =
𝑚𝑔
𝑚
× 100%
2) The percentage of coarse sand in the original sample was calculated from the following
equation:
Percentage coarse sand (2.0 mm to 0.6 mm) =
𝑚𝑐𝑠
𝑚
× 100%
3) The percentage of medium sand in the original sample was calculated from the following
equation:

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Percentage medium sand (0.6 mm to 0.2 mm) =
𝑚𝑚𝑠
𝑚
× 100%
4) The percentage of fine sand in the original sample was calculated from the following equation:
Percentage fine sand (0.2 mm to 0.06 mm) =
𝑚𝑓𝑠
𝑚
× 100%
Sedimentation:
1) The observed data and the computed quantities were recorded in a table containing the
following columns:
1 2 3 4 5 6 7 8 9
Date Time Temperature Elapsed time Rh
1
Rh = Rh
1
+ Cm D Rh + mt - x K%
where
Rh
1
is the hydrometer reading at the upper rim of the meniscus. This was made by reading
the decimals only and placing a decimal point between the third and fourth decimal
places. For instance, the density 1.0325 would read Rh
1
= 32.5.
Cm is the meniscus correction.
mt is the temperature correction.
x is the dispersing agent correction.
2) The equivalent particle diameter, D, was determined by means of a monographic chart for the
application of Stokes’ Law. To do this, a value of the constant B was obtained by placing a
straightedge across the relative density, Gs, and the temperature, T, scales at the appropriate
values. The value of B obtained was noted.
3) A value of velocity, v, was obtained by placing a straightedge across the hydrometer reading,
Rh, and time, t, scales at the appropriate values.
4) A value for the equivalent particle diameter, D, was obtained by placing the straightedge across
the velocity and B scales at points corresponding to the values of v and B.
5) The temperature correction, Mt, shall be obtained from the temperature correction chart and be
added to the quantity (Rh - x).
6) The percentage by mass, K, of the particles smaller than the corresponding equivalent particle
diameters were calculated from the equation:
K =
100Gs
m(Gs−1)
(Rh + Mt − x)
where

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m is the total dry mass of the soil after pre-treatment.
Gs is the relative density of soil particles.
7) The value of K was calculated for all values of D obtained and expresses as a percentage of the
particles finer than the corresponding values of D. These percentages were then expressed as
cumulative percentages of the pre-treated sample.
Alternatively,
The velocity of a spherical particle sinking in a fluid is given by Stokes’ Law as
V =
g
18η
(Gs − γω)D2
cms−1
where
If t (sec) is the same time taken for a particle of diameter D to fall through a distance HR (cm), then
V =
HR
t
cms-1
D = √
18η∗HR
g(Gs−γω)t
cm
When soil in water suspension is shaken up in a glass cylinder and then left to settle for a time t
(sec), then at any given depth–such as HR–below the surface, all the particles larger than a certain
diameter D will be absent. This is so because all the particles falling faster than V =
HR
t
must have
fallen to points deeper than HR so only particles smaller than
D =√
18η∗HR
g(Gs−γω)t
cm
i.e. =√
1800η∗HR
g(Gs−γω)t
mm are present at this level
The concentration at this level of particles finer than this remains unchanged since all particles of
any one size all settle at the same rate. If the original concentration of the suspension when
settlement starts is W g/ml, the concentration at every level, at all times after this will be less than
W.
Gs = specific gravity
γω = density of water in g/ml (1.0)
D = diameter of the particle in cm
g = gravitational acceleration in cm/s2
(981)
η = viscosity of water at T° in Poise or cmg-1
s-1
(9.38)

15. F16/1585/2015
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DATA SHEET DATE: 25/10/2016
Hydrometer No.: 48307 Meniscus Correction, Cm = 0.5
Specific gravity (measured/assumed) = 2.65 Temperature Correction, Mt = +3
Weight of dry soil = 50 g Rw = 1.0
K =
100Gs
m(Gs−1)
(Rh + Mt − x), where Rh + Mt − x = Rh − Rw
Elapsed
time in
min.
Temp.
(°C)
t (sec) Hydrometer
Reading,
Rh
1
(g/ml)
Rh HR
(cm)
D (mm) Rh-Rw K (%)
0.5 23 30 27.5 28 9.1 1.78 27 86.73
1 23 60 26 26.5 9.7 1.30 25.5 81.91
2 23 120 21.5 22 11.5 1.00 21 67.45
4 23 240 16 16.5 13.7 0.77 15.5 49.79
8 23 480 11 11.5 15.7 0.58 10.5 33.73
15 23 900 7.5 8 17.1 0.45 7 22.48
30 23 1800 4.5 5 18.3 0.33 4 12.85
60 23 3600 4.5 5 18.3 0.23 4 12.85
120 23 7200 4.5 5 18.3 0.16 4 12.85
240 23 14400 4.5 5 18.3 0.12 4 12.85
1440 23 86400 4.5 5 18.3 0.05 4 12.85
*Rh = Rh
1
+ Cm

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ATTERBERG LIMITS
DETERMINATION OF LIQUID LIMIT AND PLASTIC LIMIT
LIQUID LIMIT
SCOPE
This method covers the determination of the liquid limit of air-dried soil, i.e. the moisture content
at which a soil passes from plastic state to the liquid state.
APPARATUS
1) A flat glass plate.
2) Two palette knives.
3) Liquid limit device.
4) Grooving tool and gauge.
5) A wash bottle and a damp cloth.
6) Moisture content dishes.
PROCEDURE
1) The liquid limit device was inspected to determine that the device was clean, dry and in good
order, that the cup fell freely when raised to its maximum height where the 1 cm gauge could
pass between it and the base.
2) A sample weighing at least 200 g was taken from the material passing the No. 36 BS test sieve.
The sample was placed on the flat glass plate and mixed with water until the mass became a
thick homogenous paste.
3) A portion of the sample was placed 3
/4 full in the cup, levelled off parallel to the base and
divided with a grooving tool along the diameter through the centre of the hinge facing the
direction of the movement.
4) By tuning the crank at the rate of two revolutions per second, the soil came into contact at a
distance of 1
/2 in. (13 mm) and the number of blows at which this occurred recorded, and the
moisture content taken for drying.

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5) The aforementioned was repeated with the addition of a little more water in order to get more
moisture contents with different number of blows. When the moisture contents were plotted,
they were evenly distributed over the range of 10 to 50 blows.
Calculation:
The moisture content and corresponding number of blows were plotted on a semi-logarithmic chart
with either the moisture content or the number of blows as ordinates, and the other as abscissae on
the logarithmic scale. The line of best fit was then drawn through the plotted points.
Results:
The moisture content corresponding to the intersection of the ‘flow curve’ with the 25 blows was
taken as the liquid limit (LL) of the soil.
PLASTIC LIMIT
SCOPE
This method covers the determination of the lowest moisture content at which the soil is plastic.
APPARATUS
1) A flat glass plate.
2) Two palette knives.
3) A wash bottle and a damp cloth.
4) Moisture content dishes.
5) A length of metal rod 1
/8 in. (3 mm) diameter.
PROCEDURE
1) About 20 g of the soil was taken from the material passing the No. 36 BS sieve and thoroughly
mixed with water on the glass plate to make it homogenous and plastic enough to be shaped
into a ball.
2) The ball of soil was rolled between the palm and the glass plate until it resulted in a thread of
1
/8 in. (3 mm) and crumbled.

18. F16/1585/2015
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3) The portions of the crumbled soil threads were put in a container and moisture content
determined. One more moisture content was determined and the average obtained. This
average was taken as the plastic limit (PL) of the soil.
Calculation of the plasticity index of the soil sample:
The plasticity index was calculated from the following formula;
PI = LL – PL
Reporting of results:
When the LL and/or the PL cannot be determined, the PI shall be reported as NP (non-plastic).
When PL is equal to or greater than LL, the PI shall be reported as 0 (zero).
DATA SHEET DATE: 25/10/2016
LIQUID AND PLASTIC LIMITS
Liquid limit using the Casagrande Apparatus:
Test Details: Proportion of sample retained on 425 μm BS test sieve.
Soil condition: Natural moisture content/Air dried/unknown.
Soil equilibrated with water for 1
/60 h.
Height of fall = 10 mm
TEST NO. 1 2 3 1 2
TYPE OF TEST LL LL LL PL PL
NO. OF BLOWS (LIQUID LIMIT TEST) 10 27 49 – –
CONTAINER NO. 29 13 12 26 27
MASS OF WET SOIL + CONTAINER (g) 66.6 72.5 71.7 26.4 36.2
MASS OF DRY SOIL + CONTAINER (g) 50.7 54.8 53.7 23.3 33.5
MASS OF CONTAINER (g) 28.3 29.3 28.2 16.0 27.4
MASS OF MOISTURE (g) 15.9 17.7 18.0 3.1 2.7
MASS OF DRY SOIL (g) 22.4 25.5 25.5 7.3 6.1
MOISTURE CONTENT (%) 71.0 69.4 70.6 42.5 44.3

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Results:
Liquid Limit (LL) = 70.36 %
Plastic Limit (PL) = 43.4 %
Plasticity Index (PI) = 26.96 %
10, 71.0
27, 69.4
49, 70.6
69.2
69.4
69.6
69.8
70.0
70.2
70.4
70.6
70.8
71.0
71.2
0 10 20 30 40 50 60
Moisture
Content
Number of Blows
Flow Curve
25

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DETERMINATION OF THE PARTICLE SIZE DISTRIBUTION
SCOPE
This method covers the quantitative determination of the particle size distribution in a soil sample
down to the fine sand size.
APPARATUS
1) Set of sieves.
2) Balance.
3) Trays.
4) Oven.
PROCEDURE
1) About 500 g of oven dried soil was taken.
2) The set of sieves was arranged such that every upper sieve had a larger opening than the sieve
below it.
3) The soil was transferred to the top sieve and the set of sieves agitated for about 10 minutes.
4) The test sieves were agitated so that the soil sample rolled in a regular motion over the test
sieves.
5) After the soil had been agitated well, the soil retained on each sieve was transferred to the
balance to weigh the amount of soil retained on each sieve.
Calculation: The gradation curve was plotted on a semi-log chart provided.
Result: The composition of soil was indicated.

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DATA SHEET DATE: 25/10/2016
Total Weight of Dry Sample = 500 g
Sieve Size Weight Retained
[each sieve] (g)
Percentage
Retained [each
sieve] (%)
Percentage
Retained
[cumulative] (%)
Percentage
passing (%)
21
/2 in. – – – –
2 in. – – – –
3
/4 in. – – – –
3
/8 in. 37.8 7.56 7.56 92.44
3
/16 in. 135.1 27.02 34.58 65.42
No.7 149.5 29.90 64.48 35.52
No.14 91.2 18.24 82.72 17.28
No.25 53.3 10.66 93.38 6.62
No.36 16.5 3.30 96.68 3.32
No.52 6.0 1.20 97.88 2.12
No.100 6.1 1.22 99.10 0.90
No.200 2.4 0.48 99.58 0.42
Pass 200 2.1 0.42 100.00 0.00
Total 500 100 – –

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METHODS OF DETERMINING SPECIFIC GRAVITY OF SOIL
SCOPE
This method covers the determination of specific gravity of soil of medium and coarse texture after
sieving through sieve No.7.
APPARATUS
1) A density of approximately 50ml capacity.
2) A vacuum desiccator or water bath.
3) Drying oven.
4) A balance readable and accurate to 0.001 g.
5) Vacuum pump (if vacuum desiccator is to be used).
6) A glass rod.
7) A wash bottle, water or paraffin.
PROCEDURE
1) The oven dried bottle was weighed to the nearest 0.001 g (W1).
2) About 15 g of oven dried was taken and sieved through BS sieve No.7. It was then put into the
density bottle and weighed to the nearest 0.001 g (W2).
3) Air-free distilled water or paraffin was added to only just cover the sample. It was then placed
in the vacuum desiccator or water bath to evacuate the air. The bottle remained in the desiccator
until no further air was released from the sample.
4) The bottle and contents were then removed from the desiccator and air-free liquid added until
the bottle was full. It was then stoppered and weighed (with contents) to the nearest 0.001 g
(W3).
5) The bottle was then completely cleaned and filled with air-free liquid, and stoppered. The dry
bottle was then wiped and weighed to the nearest 0.001 g (W4).

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DATA SHEET DATE: 25/10/2016
Sample passing BS Sieve No.: 7 (2.36 mm) Temperature: 20 ± 1°C
SAMPLE NO. 1
BOTTLE NO. 3
MASS OF EMPTY BOTTLE, W1 65.4 g
MASS OF BOTTLE + SOIL, W2 75.4 g
MASS OF BOTTLE + SOIL + WATER, W3 186.4 g
MASS OF BOTTLE FULL OF WATER, W4 180.1 g
MASS OF WATER USED, W3 – W2 111 g
MASS OF SOIL USED, W2 – W1 10 g
VOLUME OF SOIL, [W4 – W1] – [ W3 – W2] 3.7 cm3
SPECIFIC GRAVITY OF SOIL,
W2− W1
[W4− W1]−[W3− W2]
2.703
AVERAGE GS 2.7