Determination of specific gravity of soils

Aim: Determination of specifte grausty of soils "Particle of coarse and

fine grained soil
Codal reference: 2710-3-(1980)
Apparatus: Density bottle, Balance, Pycommeter, Water bath,
desicator oven, etc.
PROCEDURE:
 The Complete density bottle with stopper, shall be dried at
105degree-110degree, Cooled in the desicator and weighed to
the nearest 0.01g(m1)
 The 50g Sample obtained as described in the procedure for the
preparation of distributed samples for testing shall if nessary be
ground to pass 4.75mm & 2mm Sieve
 A 5 to 10g of Samples shall be obtained by riffiling, and oven
dried at 105-110°C. This sample shall be transferred to density
bottle Sufficient air-free distilled water should be added to that
the soil in the bottle is just Covered. Then it is placed in Vaccum
desicator.
 The Vaccum shall be released and the led of the desicator
removed. The battle shall then be cleaned out and filled
Completely With air free liquid, the stopper inserted and then
the Whole immersed in the Constant temperature bath for 1 hour
or until if has attained the Constant temperature for bath. If there
an apparent decrease in the Volume of the liquid.
 The Stopper shall be removed and further liquid added to fill
bottle and the Stopper replaced, The Stopper bottle shall than be
returned to the botch and sufficient time shall be allowed to
elapse after this operation to ensure that the bottle and its
content again attain the constant temperature. If the bottle still
not completely full this process shall be repeated
 The bottle the bottle Shall than be taken out of the bath. wiped
dry and Weighed to the nearst 0.01g (m)

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G-Specific gravity of Water.
m1=Mass of density bottle in g.
m2=Mass of bottle and dry coil in g.
m3=Mass bottle Soil and liquid in g.
m4=Mass of bottle when full of liquid g.

Result:

Specific gravity of red soils.

(a) Densit "Density bottle method = … … … .
(b) Pycnometer Method = … … … .

Specific gravity of black Cotton foil

(a) Density bottle method = … … … .
(b) Pyconmeter method = … … … .

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 Determination of Dry dingsty of land (in-situ) the by the sand
replacement method

Aim: Determination in place of the dry density of natural Or

compacted fine and medium grained soil. This method is applicable to
layer not exceeding 150mm in thickness.

Codal reference:

Apparatus: Small pouring cylinder, tools for excavating holes,

Calibration container, balance plane Surface, metal tray with holes
etc.

Material: clean, uniformly graded natural and passing the 1mm IS

Sieve and retained on the 600 IS- Sieve shall be used. It shall be free
from organic matter, and shall have been oven dried and stored for a
suitable periat to allow ite Water content to reach equilibrium with
atmospheric humidity.

PROCEDURE:-

 Weight of the sand sand found in the Cone of the pouring

cylinder.
 The Pouring cylinder the cylindar Shall be filled so that the
level of the of sand cylinder is with in about 10mm, of the top.
It’s total initial Weight (Wi) shall be found and shall be a
maintained constant throughout the tests for which the
Calibration is used to volume of sand equivalent to the

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 excavated hole in soil shall be allowed to rumour of the cylinder
under gravity. The Shattered on the pouring Cylinder shall be
than closed and the cylinder placed on a plane surface such as a
glass plate
 The container Containing the soil Core shall be weighed to the
nearest gram (ws)
 The Soil Core shall be removed from the Cutter and a
representative Sample shall be placed in an air tight Container
and it’s Water Content.

Note:-
 necessary to make a mumber of repeat determin -ation and to
oversea results, since the dry density of the soil Varies
appreciably from point to point. The number of determinations
should be such that of additional one Would mot after the
average significant.

 Results:

Dry unit height of given soil. Sample (in situ) __________ kN/m³.

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 Direct shear test

Codel reference: IS 2780-13 (1986)

Aim: Determination of shear test (strength) of soil with a maximum particle size of both 4.75mm
passing and retained (both Cohesive & Cohansionless).

APPARATUS:

1. loading frame
2. The Vertical Stress on the sample shall remain Vertical and content during the test and there
shall be arrangement To measure Compression.
3. The Shear Stress or Strain Can be applied in the Dividing plane of the two parts of shear.
4. It shall be Possible to maintain a Content role of increase in stress during the test with
arrangement to get different rates of stress increase.
5. In Case of a strain-Controlled apparatus, the strain rate Should remain Content respective of
the Stress. Suitable arrangement Shall be provided to obtain different, Strain rates.
6. No Vibration should be transmitted to the Sample during the test and there should be any
loss of Shear force due to friction between the loading frame and the shear box – Container
assembly.
7. Weights→ Proving ring
8. Micrometer dial gauge
9. Sample trimmer / Core Cutter→ Balance.

Remoulded specimen:

 Cohesive soils may be compacted to the required density and moisture content the sample
atracted and then trimmed, to the required density and moisture content directly into the
shear box after fixing the two halves of the shear box together by means of the fixing screws
 cohonsionless soils may be tamped in the shear box itself with the base plate and plate or
porous stone as required in placed at the bottom of the box.

PROCEDURE

 Undrained text: The shear box with the specimen plan grid plate Over the base plate at the
bottom of the specimen and plain grid plate at the top of the specimen should be fitted into
position in the load frame. The Serretions of the grid Plates should be at right angles to the
direction of shear. The loading Pod should be placed on the top grid plate. The water jacket
should be provided so that the sample does not get dried during the test the Sample. The
required normal stress should be applied and the rate of longitudinal displacement shear
stress application So adjusted that no drainage. The Shear load readings indicated by the

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 provingring assembly and the Corresponding longitudinal displacement, Whichever occurs
first. The shear loading readings are noted down regular intervals. If necessary the vertical
Compression if any of the soil spicimen may be measured by Serve as a check to ensure that
drainage has not taken place from the Soil speciemen. At the end of the test, the specimen
should be removed from the box and the final moisture Content measured. A minimum of
three (preferably fours) tests should be mode on Seperate speciemen of the same density.

RESULT:-

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 Determination of uncompened Compresive Strength

Codal reference: IS 2720 (Part 10): 1991

Unconfined Comprenive Strength (qu): It is the load Per Unit area at which on unconfined
cylindrical speciemen of soil Will fail in axial Comprensive test.

APPARATUS
a) Compression device
b) Platform Weighing Scale equipped
c) Hydraulic laading device
d) Screw jack With a provingring.
e) Provingring
f) Deformation dial gauge.

Preparation of test specimen: The Specimen for the test shall have a minimum diameter for
the test shall have of 38mm and the largest particle Contained within the test specimen
shall be Smaller than 1/8 of the Specimen diameter. If after Completion of test on
undistrubted Sample.
Remoulded Specimen: The Specimen may be prepared either from a failed Undistrubted
specimen or from a disturbed specimen In the case of field undistrubed Specimen, the
material shall Wrapped in a thin rubber membrane and thoroughly worked With the fingers
to ensure complete remoulding. Care shall be taken to avoid entrapped air, to obtain a
uniform density, to remould to the Same Void ratio as that of undisturbed specimen, and to
Preserve the natural Water Content of the soil.
Compacted Specimen: when Compacting distrubed material it shall be done using a mould
of circular crossection With dimensions Corresponding to those table. Can be prepared at
any Predetermined Water Content and denesity.
Procedure:
The initial length, diameter and Weight of the specimen shall be measured and the
specimen placed on the bottom plate of the loading device. The upper plate Shall be
adjusted to make Contact with the specimen.
The deformation dial gauge shall be adjusted to a suitable reading, Preferably in multiples of
100. Force shall be applied to as to produce axial strain of a rate of 0.5 to 2%. Perminute
causing failure with 5 to 10. The force reading shall be taken of suitable intervals of the
deformation dail gauge readings

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•The specieman shall be compressed untill failure Surface have defienetly developed, or the
stress strains Curve is well port, its Peak or until in axiall Strain of 20% in reached.

•The failure pattern shall be sketched Carefully and shown on the data sheet on the sheet
preseative the stress-Strain plot the angle between failure surface and the horizontal may
be measured, of possible, and reported.

Formule:

1. Axial strain(€)=∆L/L
∆L= Change in length
L= Initial length

PROCEDURE:
 Measure the length, diameter & man of the Specimen accurately
 Cover the pedestal of the triaxial Cell with a Soil end capor keep the drainage Valve closed.
place the specimen on thesolid end cap. on the pedatal cell & place the other end Cap on
top of specimen.
 Place rubber membrane around the Specimen using. membrane Stretcher and seal the
membrane to end caps by means of rubber ringe.
 Assemble the Cell with the loading the ram initially clear of top of specimen & place it on
loading machine
 Admit the operating fluid into the cell & bring its pressure to the desired Value.
 Adjust the loading machine Such that loading ram Comes just In contact with the seat on
the top of specimen. Note the initial reading on dial measuring axial Compression
 Apply an axial Compressive force at a Constant rate such that the failures occurs within a
periods of approximately 5 to 15min. Note down the proving readings Corresponding to
known Compression gauge readings.

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  Unload the specimen & drain off the cell fluid Dismatle the Cell & take Out the Specimen.
Remove the rubber membrane & note down the mode of failure
 Repeat the text on three or more specimens different cell pressure.

Result:

The unconsolidated undrained triaxial Strength of soil _________ kg/cm².

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 Determination of liquid limit And plastic limit

Coded reference: IS: 2720-5(1985)

Aim: Determination of the liquid limit & plastic limit of Soils

APPARATUS:

a) Mechanical liquid limit device (Casagrande apprestaus)

b) Grooving tools.
c) Parcelain evaporating dish.
d) Flat glauss plate.
e) Spatule.
f) Palette Knives.
g) Oven.
h) Balance.

Soil Sample : A Sample Weighing about 120g shall be taken from the throughly mixed portion of
material Passing 426microns IS Sieve.

Adjustment of the mechanical device:

The liquid limit device shall be impacted to determine that it is clean, dry & to determine that it is
clean. dry & in good Working order that the Cup fall freely and it doesnot have to much side play at
its huge using the gauge handle of the the grooving tool or a separate gauge & by the means of the
adjustment plate of the mechinical Liquid Limit the mechanical device, the height through which
the Cup is lifted and dropped. Shall be which comes is Contact with the box falls through exactly one
centimetre for one revolution of the handle. The adjustment plate shall then be secured by
tightening the screw.

Cup Name Number of Empty weight Weight of cup Weight of cup (w2-w3)/(w3-
blows of cup (w1) g + wet + dry w1)X100
soil(w2)g soil(w3)g

WATER CONTENT DETERMINATION

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PROCEDURE: Using Casagrande' APPARATUS

A Sample of Soil weighing at least 150g from the Soil & theoughly mixed with destilled water in the
evaporating death the soil Should taken be revoixed thoroughly before the tept. A portion of the
porte Shall be placed in the Cup above the spot where the cup raty on the base, Squezed down Ey
Spread into poxition shown, With as few & bookes of the Spatula as posible and at the Same time
trimmed to o deepts of 1 centrimetre at the porot of maximum thicknew setumsog the exces poil to
the desh. The Soil in the cup soil be decided by firm Stroke of the groving tool along the dia through
the centre line of the Com follower so that a deep Starp groove of the proper dimensione is formed.

A representation. Slice of Soil appromate the width of the Spatida, extending from, about edge to
edge of the Soil Cake on sight angle to the groove & including that Pertion of the in the sort flowed
together Shau be taken in a suitable Containers & tis messture Contrat expressed percentage of the
wise determined Duen day Weight, other the operation specified Shall for at least thrice additional
triale be squeatat

Result:

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 Determination of liquid limit by Cone penetration method:
Aim: Determination of liquid limit by Cone penetration method.
Apparatus:
1. Come penetration.
2. Balance.
3. Oven.
Soil Sample: A Soil Sample Weighing about 150g from thoroughly mixed portion of the soil paring
425 micron IS sieve

PROCEDURE:

About 150g of Soil Sample obtained bas shau be Worked Well into a Case of a parte highly clayey
with addition of distilled water. In the Soils, to ensure cmiform moisture distribution, It is
recommended that the soil in the mixed State is left for sufficient time by houry) in an air tight
Container The Wet Soil parte shau be taken transfered. to cylindrical cup of Cone penetration
apparatus, ensuring that no air as trapped so this proces. Finally the Wet Soil levelled up to the top
of the cup and plate on the bare of the after Cone 5 ccc penetrometer apparater. Shalu be noted The
penetration of the Cone to the nearest millemetre If the difference in penetration (ses between 14 &
28 mm the test is repeated with suitable aldjurtimenta to moisture esther by addition of more on
the Water or exposure exposure of glass plat for reduction in the Spread parte In moriture Content.
The test Chau be then repeated at least to have 4 Sets Of Valud of penetration the range of 14 to
28mm. The exact Moisture Content of each trial shall be determined in accordance With IS: 2720

Traial Weight of cup + Depth of Weight of cup (W2-w3)/(w3-

Empty weight of
no wet soil(w2)g penetration(mm) + dry w1)x100
cup(w1)g
soil(w3)g

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