Soil Lab.manual MANOJ

GEOTECHNICAL ENGG. DESIGN AND LABORATORY. I (7CE7)

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Experiment no.:-1

Object: - DETERMINATION OF SPECIFIC GRAVITY BY PYCNOMETER.

Scope: - The object of test is to determine the specific gravity of the Soil

fraction passing 4.75 mm IS Sieve by Pycnometer.

Standard: - IS: 2720 (Part 3/ sec.-1) 1980.

Definition: - Specific gravity G is defined as the ratio of the mass of a given volume of

the substance to the mass of an equal volume of water.

Apparatus:- (1) Pycnometer of approximately 900 ml. capacity with conical brass cap.

(2) Thermostatically controlled water bath maintained within 27 ± 0.2°C.

(3) Thermostatically controlled oven of capacity 250°C.

(4) Analytical balance of sensitivity 1 gm.

(5) 4.75 mm. IS Sieve.

(6) Glass rod.

(7) Deaired, distilled water.

Brief Procedure: - (1) Clean the Pycnometer and dry it. Find the mass (M1) of Pycnometer, brass cap and

washer, accurate to 1 gm. (2) Take approximately 200 to 400 grams of oven dried soil sample. (3) Transfer the soil sample in to Pycnometer. (4) Find the mass of Pycnometer and the soil sample together with stopper (M2) gm. (5) Add sufficient air free distilled water in to the Pycnometer to half its height and mix it

thoroughly with glass rod. (6) Add more water and stir it. Replace the screw top and fill the Pycnometer flush with

hole in the conical cap. Dry the Pycnometer from outside and find the mass (M3). (7) Empty the Pycnometer; clean it thoroughly and fill it with distilled water to the hole

of the conical cap and find mass (M4). (8) Repeat above steps for two more determinations of specific gravity. (9) Make at least two determinations for each test.


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Observation Table:-

DATA AND OBSERVATION SHEET FOR DETERMINATION OF SPECIFIC GRAVITY BY

PYCNOMETER

S.No. Determination No. 1 2 3

1 Pycnometer No.

2 Mass of Pycnometer(M1)g

3 Mass of Pycnometer +soil (M2)g

4 Mass of Pycnometer +soil + water (M3)g

5 Mass of Pycnometer + water (M4)g

6 Specific Gravity at T⁰C

7 Average Specific Gravityat T0C.

Calculations:- If distilled water is used as an air free liquid, calculate the specific gravity of

the soil particles “G” from the equation:-

G= (M2-M1) ⁄ (M2-M1) − (M3-M4)

Report:- (1) Report the individual and the mean results to the nearest 0.01 at 27⁰ C.

(2) If the two results differ by more than 0.03, Repeat the test.

Result: - The specific gravity of the given soil sample at 27⁰ C is G=……………….

Precautions:- (1) Soil should not be dried more than 80⁰ C, if there is any doubt in change of specific gravity by

oven drying due to loss of water during hydration.

(2) It has been observed that largest source of error in the test is due to the difficulty in ensuring

the complete removal of air from the sample.

(3) To obtain reliable and quicker results the soil should be left under vacuum for several hours,

preferably overnight shaking the bottle in hand once or twice interrupting the vacuum.

Comment: - (1) The Pycnometer or flask method is used for coarse grained soils. (2) The other methods are by 50 ml. density bottle or a 500 ml. flask. (3) For cohesive soil density bottle is used with kerosene as liquid.


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INTERPRETATION AND REPORTING:-

Unless or otherwise specified specific gravity values reported shall be based on water at 270C. So the

specific gravity at 270C = K (Sp. gravity at T0C.)

The specific gravity of the soil particles lay within the range of 2.65 to 2.85. Soils containing

organic matter and porous particles may have specific gravity values below 2.0. Soils having heavy

substances may have values above 3.0.

Questions:-

(1) (2) (3) (4) (5)

PYCNOMETER


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Experiment no.:-2 Object: - GRAIN SIZE DISTRIBUTION BY SIEVING.

Standard: - IS: 2720 (Part 4/ sec.-3&4) 1985.

Objective: - (1) Select sieves as per I.S specifications and perform sieving.

(2) Obtain percentage of soil retained on each sieve.

(3) Draw graph between log grain size of soil and % finer.

(4) The object of this experiment is to determine grain size distribution of coarse grained

soil by sieving. The test covers both coarse sieve analysis (for gravel fraction) as well

as fine sieve analysis (for sand fraction).

Need and Scope of Experiment:-

The grain size analysis is widely used in classification of soils. The data obtained from

grain size distribution curves is used in the design of filters for earth dams and to

determine suitability of soil for road construction, air field etc. Information obtained

from grain size analysis can be used to predict soil water movement although

permeability tests are more generally used.

Apparatus:-

(1) Balance accurate to 0.1 gm.

(2) I.S sieves 100, 75, and 22,10,4.75,2,1 (in mm.)

(3) I.S sieves 600, 425, 300, 212, 150, and 75. (In micron.)

(4) Rubber pestle and mortar.

(5) Mechanical Sieve Shaker.

(6) Metal trays.

(7) Sieve brushes & a wire brush.

(8) Riffler.

The grain size analysis is an attempt to determine the relative proportions of different

grain sizes which make up a given soil mass.


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Knowledge of Equipment:-

(1) The balance to be used must be sensitive to the extent of 0.1% of total weight of

sample taken.

(2) I.S 460-1962 is too used. The sieves for soil tests: 4.75 mm to 75 microns.

Brief Procedure: -

(1) For soil samples of soil retained on 75 micron I.S sieve.

(2) The proportion of soil sample retained on 75 micron I.S sieve is weighed and

recorded weight of soil sample is as per I.S 2720, Take 200 gm. dried soil.

(3) I.S sieves are selected and arranged in the order as shown in the table.

(4) The soil sample is separated into various fractions by sieving through above sieves

placed in the above mentioned order.

(5) The weight of soil retained on each sieve is recorded.

(6) The moisture content of soil if above 5% it is to be measured and recorded.

(7) No particle of soil sample shall be pushed through the sieves.

(8) Dry sieve analysis: -If the soil sample contains little or no fines (Passing 75 micron

IS Sieve) dry sieve analysis may be carried out.

(9) The gravel fraction and sand fraction are first separated by dry sieving through

4.75 mm. sieve.


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Observation Table No. (1):-

Gravel or coarse fraction retained on 4.75 mm. sieve, mass retained on 4.75 mm. sieve =………gm.

Mass of dry soil sample = 1000 gm.

OBSERVATION SHEET:-1

S.No.

IS Sieve

size in

(mm.)

Particle

size D

(mm.)

Mass

retained in

each sieve

(gm.)

Percentage

Retained on

each sieve

Cumulative

% Retained

on each sieve

Cumulative

% Finer

(N)

Remarks

1 100 100

2 75 75

3 19 19

4 10 10

5 4.75 4.75

Observation Table No. (2):-

Sand or Finer fraction Passing 4.75 mm. sieve.

Mass of dry soil sample = 200 gm.

Moister content =

Weight of soil sample =

OBSERVATION SHEET:-2

S.No.

IS Sieve

size in

(mm.)

Particle

size D

(mm.)

Mass

retained in

each sieve

(gm.)

Percentage

Retained on

each sieve

Cumulative

% Retained

on each sieve

Cumulative

% Finer

(N)

Remarks

1 2 2

2 1 1

3 0.600 0.600

4 0.425 0.425

5 0.300 0.300

6 0.212 0.212

7 0.150 0.150

8 0.075 0.075


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Graph:-

Draw graph between log sieveVS. % Finer.

The graph is known as grading curve.

Corresponding to 10 %, 30 % and 60 % finer,

Obtain diameters from graph are designated as D10, D30, D60.

Calculation:-

The percentage of soil retained on each sieve shall be calculated on the basis of

total weigh of soil sample taken. Cumulative percentage of soil retained on

successive sieve is found.

Result: -

Comment: -

Questions:- (1) (2) (3) (4) (5)


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Experiment no.:-3

Object: - DETERMINATION OF WATER CONTENT BY PYCNOMETER.

Object and Scope:-

The object of the test is to determine the water content of a moist soil sample by Pycnometer.

For this determination, by specific gravity (G) of soil solids must be known.

Material and Apparatus:-

(1) Pycnometer of about 900 ml. capacity, with a conical brass cap screwed at its top.

(2) Balance sensitive to 1 gm.

(3) Glass rod.

Brief Procedure: -

(1) Clean the Pycnometer and dry it. Find the mass (M1) of the Pycnometer, brass cap and

the washer, accurate to 1 gm.

(2) Put about 200 gm to 400 gm of wet soil sample in the Pycnometer and find its mass

with its cap and washer (M2).

(3) Fill the Pycnometer to half its height and mix thoroughly with the glass rod. Add more

water and stir it.

(4) Replace the screw top and fill the Pycnometer flush with the hole in the conical cap.

(5) Dry the Pycnometer from outside and find its mass (M3).

(6) Empty the Pycnometer, clean it thoroughly and fill it with clean water to the hole of

the conical cap and find its mass (M4).


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Observation Table:-

DATA AND OBSERVATION SHEET FOR WATER CONTENT DETERMINATION BY PYCNOMETER

Specific gravity =……………………………

S.No. Determination No. 1 2 3

1 Mass of Pycnometer(M1)g

2 Mass of Pycnometer +Moist soil (M2)g

3 Mass of Pycnometer +soil + water (M3)g

4 Mass of Pycnometer + water (M4)g

5 Water content (W) %

Specific gravity = 2.66

Calculations:- Water content “W” is calculated from equations:-

W= [M2-M1 / M3-M4 (G-1 / G)-1] ×100

Result: - water content of given soil sample = ………………………. %.

Comment: -


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Experiment no.:-4

Object: - DETERMINATION OF LIQUID LIMIT BY CASAGRANDE’S

APPARATUS.

Scope: - The object of the test is to determine the liquid limit of the soil sample using Casagrande type mechanical liquid limit Apparatus.

Standard: - IS: 2720 (Part 5) 1985.

Definition: - Liquid limit is defined as the water content at which the soil changes from liquid state to plastic state.

Apparatus:- (1) Casagrande apparatus confirming to IS: 9259-1979 (2) Grooving tool. (Casagranded or BS Tool) (3) Balance of capacity 500 grams and sensitivity 0.01gram. (4) Thermostatically controlled oven with capacity up to 250 0C. (5) Porcelain evaporating dish about 12 to 15cm in diameter. (6) Spatula flexible with blade about 8cm long and 2cm wide. (7) Palette knives with the blade about 20cm long and 3cm wide. (8) Wash bottle or beaker containing distilled water. (9) Containers airtight and non- corrodible for determination of moisture content. (10) 425 micron sieve. (11) Desiccators.

Brief Procedure: -

(1) Take representative soil sample of approximately 120gms passing through 425 micron ISsieve and mix thoroughly with distilled water in the evaporating dish to a uniform paste.

(2) The paste shall have a consistency that will require 30 to 35 drops of the cup to cause therequired closure of the standard groove.

(3) Leave the soil paste to stand for 24 hours to ensure uniform distribution of moisture throughout the soil mass.

(4) Remix the soil thoroughly before the test. (5) Place a portion of the paste in the cup above the spot where the cup rests on

the base,squeeze down and spread in to position with a few strokes of the spatula as possible and atthe same time trim to a depth of 1cm at the point of maximum thickness.

(6) Make a clean, sharp groove by a grooving tool along the diameter through the centerline ofthe cam follower.

(7) Drop the cup from a height of 10 ± 0.25 mm by turning the crank at the rate of two revolutions/sec, until the two halves of the soil cake come in contact with the bottom of thegroove along the distance of about 12mm.


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(8) Record the number of drops required to cause the groove close for the length of 12mm.

(9) Collect a representative slice of sample of soil approximately the width of spatula,extending from about edge to edge of the soil cake at right angle to the groove in to an airtight container and keep in the oven for 24hrs,maintained at a temperature of 1050Cto 1100C and express its moisture content as the percentage of the oven dried weight.

(10) Transfer the remaining soil in the cup to the evaporating dish and clean the cup and thegrooving tool thoroughly.

(11) Repeat the operation specified above for at least three more additional trials (minimum offour in all) with soil collected in evaporating dish to which sufficient water has been addedto bring the soil to more fluid condition.

(12) In each case record the number of blows and determine the moisture content as before.

(13) The specimens shall be of such consistency that the number of drops required to close thegroove shall not be less than 15 or more than 35.

Observation Table:-

DATA AND OBSERVATION SHEET FOR LIQUID LIMIT DETERMINATION

S.No. Determination Number 1 2 3 4

1 Number of blows

2 Container Number

3 Mass of Container + wet soil (g)

4 Mass of Container + dry soil (g)

5 Mass of water (g)

6 Mass of Container (g)

7 Mass of oven dry soil (g)

8 Water content (%)

Liquid Limit (From Graph) =…………………%. Flow Index (From Graph) = …………………………..%.


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Report:- (1) Plot a flow curve with the points obtained from each determination on a semi

logarithmicGraph representing water content on the arithmetical scale and the no of drops on theLogarithmic scale.

(2) The flow curve is a straight line drawn as nearly as possible through the four or more plotted points.

(3) The moisture content corresponding to 25 drops as read from the curve shall be rounded off to the nearest second decimal and is reported as liquid limit of the soil.

Precautions:-

(1) This test should proceed from the drier (more drops) to the wetter (less drops) condition of the soil.

(2) This test may also be conducted from wetter to drier condition provided drying is achieved by kneading the wet soil and not by adding dry soil.

(3) Use distilled water in order to minimize the possibility of the ion-exchange between the soil and impurities in the water.

Result:- The water content corresponding to 25 blows is taken as the liquid limit of the soils.

Liquid limit of the given sample of soil = ……………………………… %.

Comments: -

Remarks:-


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Questions:- (1) (2) (3) (4) (5)

LIQUID LIMIT TEST BY CASAGRANDE’S APPARATUS.

Divided soil cake before test

Soil cake after test


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Experiment no.:-5

Object: - DETERMINATION OF PLASTIC LIMIT.


Definition: - Plastic Limit is defined as minimum water content at which soil remains in

plastic state.

Apparatus:- (1) Porcelain evaporating dish about 12cm in diameter.

(2) Flat glass plate 10mm thick and about 45cm square or longer.

(3) Spatula flexible with the blade about 8cm long and 2cm in wide.

(4) Ground glass plate 20 x 15 cm.

(5) Airtight containers.

(6) Balance of capacity 500grams and sensitivity 0. 01gram.

(7) Thermostatically controlled oven with capacity up to 250 0C.

(8) Rod 3mm in diameter and about 10cm long.

Brief Procedure: - (1) Take representative soil sample of approximately 20g from the portion of the material

passing 425 micron IS sieve and mix thoroughly with distilled water in an evaporating dish

till the soil mass becomes plastic enough to be easily molded with fingers.

(2) In the case of clayey soils, leave the soil mass to stand for 24 hours to ensure uniform

distribution of moisture throughout the soil.

(3) Form a ball with about 8 grams of this soil mass and roll between the fingers and the glass

plate as shown in Fig: 2.7.1 with just sufficient pressure to roll the mass into a thread of

uniform diameter throughout its length.

(4) The rate of rolling shall be between 80 and 90 strokes/minute counting the stroke as one

complete motion of the hand forward and back to the starting position again.

(5) Continue the rolling till the thread crumbles exactly at 3mm diameter.

(6) If the soil thread doesn’t crumble exactly at 3mm knead the soil together to a uniform mass

and roll it again.

(7) Continue this process of alternate rolling and kneading until the thread crumbles under the

pressure exactly at 3mm diameter.

(8) Collect the pieces of crumbled soil thread in an airtight container and determine its moisture

content.

(9) Determine the plastic limit for at least two points of the soil passing 425 micron IS sieve.


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Observation Table:-

DATA AND OBSERVATION SHEET FOR PLASTIC LIMIT DETERMINATION


1 Container Number


3 Mass of Container + oven dry soil (g)

4 Mass of water (g)



7 Water content (%)

Plastic Limit =………………………% Natural water content of field soil = …………………………..%

Report:- Report the individual and the mean of the results as the plastic limit of the soil to the nearest second decimal.

Precautions:-

At no time shall an attempt be made to produce failure at exactly 3mm diameter by allowingthe thread to reach 3mm then reducing the rate of rolling or pressure or both and continuingthe rolling without further deformation until the thread falls apart.

Result:-

Comments: -

Questions:- (1) (2) (3) (4) (5)


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PLASTICITY INDEX

Definition:- The plasticity Index is defined as the numerical difference between its Liquid Limit andPlastic Limit.

Report:- Plasticity Index = Liquid Limit - Plastic Limit.

Precautions:- (1) In the case of sandy soils plastic limit should be determined first. (2) When plastic limit cannot be determined the Plasticity Index should be

reported as NP (Non-Plastic). (3) When the plastic limit is equal to or greater than liquid limit, the plasticity

index shall be reported as zero.

Plastic Limit Test

Plastic Limit Test


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Liquid limit device, Porcelain (Evaporating) dish, Flat grooving tool with gage, Eight

moisture cans, Balance, Glass plate, Spatula, Wash bottle filled with distilled Water,

drying oven set at 105°C.


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Experiment no.:-6

Object: - DETERMINATION OF SHRINKAGE LIMIT.

Standard: - IS: 2720: 1972/78 (Part VI).

Definition: - Shrinkage limit (Ws):-Shrinkage limit is defined as the maximum water

content at which a reduction in water will not cause a decrease in the

volume of a soil mass. It is lowest water content at which a soil can still be

completely saturated.

Apparatus:- (1) Evaporating dish (2 Nos.) of porcelain, about 12 cm. in diameter with flat bottom. (2) Shrinkage dish, of non-corroding metal, having flat bottom and 45 mm. in diameter and 15

mm. in height internally (3 Nos.). (3) Glass cup, 50 to 55 mm. in diameter and 25 mm. in height, the top rim of which is ground

smooth and level. (4) Glass plates, (2 Nos.), each 75 ×75 mm. one plate should be of plain glass and the other should

have three metal prongs. (5) Spatula. (6) Straight edge. (7) 425 micron IS sieve. (8) Balances, sensitive to 0.1 gm. and 0.01 gm. (9) Oven (Thermostatically controlled1050- 1100C) (10) Mercury. (11) Desiccator. (12) Wash bottle containing distilled water.

Brief Procedure: - (for Remoulded sample)

(1) Preparation of soil paste: - Take about 100 gm. of soil sample from a thoroughly

mixed portion of the material passing 425 micron IS Sieve.

(2) Place about 30 gm. of the above sample in evaporating dish and mix it thoroughly

with distilled water. Water added should be sufficient to fill the void in the soil

completely and make the soil pasty

(3) Determine of mass and volume of the shrinkage dish: - Clean a shrinkage dish and

determine its mass accurate to 0.1 g. To determine its volume, place the evaporating

dish and fill it to overflowing the mercury. Remove the excess mercury by pressing

the plain glass plate firmly on its top, taking care that no air is entrapped. Wipe off,

carefully, any mercury which may be adhering to the outside of the shrinkage dish.

Carefully transfer the mercury, accurate to 0.1g. The mass of mercury divided by its

density would give the volume of the shrinkage dish, which is also the volume of wet

soil pat.


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(4) Filling the shrinkage dish soil pat: - Coat the inside of the shrinkage

dish with a thin layer of silicon grease or Vaseline. In the Centre of dish,

place the soil paste, about one-third of the volume of the dish, with the

help of spatula. Tap the dish gently on a firm surface, cushioned with

layers of blotting paper or rubber sheet and allow the paste to flow

towards the edges. Place another equal installment of the paste in the

dish and make it flow toward the edges by tapping. Tapping should be

continued till the paste is compared and all the entrapped air is brought

to the surface. Repeat the process till the dish is completely filled and the

excess soil overflows. Strike off the excess soil paste with a straight edge.

Wipe off the soil adhering to the outside of the dish.

(5) Determine of wet and dry mass of soil pat: - weight immediately

the shrinkage dish plus the wet soil pat, accurate to 0.1 g. keep the

shrinkage dish open to air until the colour of pat turns from dark to light.

Keep the shrinkage dish in the oven and thus dry the pat to constant mass

at 1050- 1100 C. Cool the dish in a desiccators and weight immediately.

(6) Determine of volume of dry soil pat: - To determine the volume of the

dry soil pat, keep the glass cup in the evaporating dish. Fill the cup to

overflowing with mercury. Remove the excess mercury by pressing the

glass plate with the three prongs firmly over the top of the cup. Transfer

the cup carefully to another evaporating dish, carefully wiping off any

mercury which may be adhering to the outside of the cup. Place the oven-

dried soil pat on the surface of mercury in the cup and carefully force the

pat into the mercury by pressing it by the same glass plate containing

three prong. Press the plate firmly on the top of the cup. Collect carefully

the displaced mercury and find its mass by accuracy of 0.01 g. the volume

of the dry soil pat is then determined by dividing this mass by the density

of mercury.


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Observation Table:-

DATA AND OBSERVATION SHEET FOR SHRINKAGE FACTORS (REMOULDED SAMPLE)

S.No. Determination Number 1 2 3

(a) Water content of wet soil pat

1. Shrinkage dish No.

2. Mass of shrinkage dish

3. Mass of shrinkage dish + wet soil pat

4. Mass of shrinkage dish + dry soil pat

5. Mass of dry soil pat (Md)

6. Mass of water

7. Water content of soil pat (w)

(b) Volume of wet soil pat

8. Evaporating dish No.

9. Mass of mercury filling shrinkage dish + mass of Evaporating dish

10. Mass of Evaporating dish

11. Mass of mercury filling shrinkage dish

12. Volume of wet soil pat V =(11)/13.6 (cm3)

(c) Volume of dry soil pat

13. Evaporating dish No.

14. Mass of mercury displaced by dry soil pat + mass of Evaporating dish

15. Mass of Evaporating dish

16. Mass of mercury displaced by dry soil pat

17. Volume of dry soil pat V =(11)/13.6 (cm3)

(d) Calculations

18. Shrinkage limit Ws ={W- (V-Vd)/Md} ×100

19. Shrinkage Ratio SR =Md/Vd

20. Volumetric shrinkage VS =(W- Ws)SR


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Calculations: - shrinkage limit (Remoulded sample) Ws =

Ws = {W- (V-Vd)/Md} ×100 {since ᵱw = 1 gm. /cm3}

Results:-

Shrinkage limit of give soil sample (Remoulded):- ………………………………%.

Comments:-

Remarks:-

Questions:-

(1) What is shrinkage limit of a soil?

(2) What is the use of shrinkage limit?

(3) What is shrinkage limit Ratio?

(4) Define volumetric shrinkage?

(5) What are consistency limits?

Shrink age Limit (Mercury Method)


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Experiment no.:-7

Object: - DETERMINATION OF LIQUID LIMIT BY CONE PENETROMETER.

Scope: - The object of the test is to determine the liquid limit of the soil sample using Cone Penetrometer Apparatus.


Definition: - Liquid limit is defined as the water content at which the soil changes from liquid state to plastic state.

The liquid limit of the soil corresponds to the water content of a paste which would give 20 mm. penetration of the soil.

Apparatus:- (1) Penetrometer: - control angle of cone 310, Total sliding mass=80 gm. (2) Cylindrical trough, 5 cm.dia & 5 cm.high. (3) Balance of capacity 500 grams and sensitivity 0.01gram. (4) Thermostatically controlled oven with capacity up to 250 0C. (5) Porcelain evaporating dish about 12 to 15cm in diameter. (6) Spatula flexible with blade about 8cm long and 2cm wide. (7) Palette knives with the blade about 20cm long and 3cm wide. (8) Wash bottle or beaker containing distilled water. (9) Containers airtight and non- corrodible for determination of moisture content. (10) 425 micron sieve. (11) Desiccators.

Brief Procedure: -

(1) Take representative soil sample of approximately 250 gm. passing through 425 micron IS sieve and mix thoroughly with distilled water in the evaporating dish to a uniform paste.

(2) The paste shall have a consistency that will require 12 to 15 mm. Penetration. (3) Leave the soil paste to stand for 24 hours to ensure uniform distribution of

moisture throughout the soil mass. (4) Remix the soil thoroughly before the test. (5) Soil pats are prepared at various water content and depth of penetration for

each pat is noted. (6) In each care record the penetration in mm. and determine the moisture

content. (7) The specimen’s shall be not less than 14 mm. or more than 28 mm. (8) A graph is plotted representing water content (w) on the X-axis and core

penetration (x) on the x-axis. (9) The best fitting lines are then drawn.


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(10) The water content corresponding to a cone penetration of 20 mm. is then taken as the liquid limit.

(11) The set of values used for the graphs should be such that the values of penetration are in the range of 14 to 28 mm.

Observation Table:-

DATA AND OBSERVATION SHEET FOR LIQUID LIMIT DETERMINATION


1 Penetration of cone in mm.

2 Container Number


4 Mass of Container + dry soil (g)

5 Mass of water (g)



8 Water content (%)

Liquid Limit (From Graph) =…………………%. Flow Index (From Graph) = …………………………..%.

Report:-

(1) Plot a flow curve with the points obtained from each determination on a semi logarithmic Graph representing water content on the arithmetical scale and the Penetration values in mm. on the Logarithmic scale.

(2) The flow curve is a straight line drawn as nearly as possible through the four or more plotted points.

(3) The moisture content corresponding to 20 mm. Penetration as read from the curve shall be rounded off to the nearest second decimal and is reported as liquid limit of the soil.

Precautions:-

(1) This test should proceed from the drier (more drops) to the wetter (less drops) condition of the soil.

(2) This test may also be conducted from wetter to drier condition provided drying is achieved by kneading the wet soil and not by adding dry soil.

(3) Use distilled water in order to minimize the possibility of the ion-exchange between the soil and impurities in the water.


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Result:- The water content corresponding to 20 mm. Penetration is taken as the liquid

limit of the soils.

Liquid limit of the given sample of soil = ……………………………… %.

Comments: -

Remarks:-

Questions:-

(1) Define liquid limit of soil? (2) What are the methods to determine liquid limit of soil? (3) What are consistency limits of soil? (4) What is plasticity of soil? (5) Will the clay become plastic when mixed with kerosene?

Cone-Penetration Apparatus

LIQUID LIMIT TEST BY CONE-PENETRATION APPARATUS


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Experiment no.:-8

Object: - DETERMINATION OF FIELD DENSITY BY CORE CUTTER.

Objectives: - The object of the test is to determine the dry density and dry unit weight of soil in-place by the core cutter.

Standard: - IS: 2720 (Part XXIV) 1988.

Need and Scope:-

(1) The in situ density of natural soil is needed for the determination of bearing capacity

of soils, for the purpose of stability analysis of slopes, for the determination of

pressures on underlying strata for the calculation of settlement and the design of

underground structures.

(2) It is very quality control test, where compaction is required, in the cases like

embankment and pavement construction.

Definition: - The dry density of the soil will be equal to the bulk density divided by (1+w).

Theory: - By conducting this test it is possible to determine the field density of the soil.

The moisture content is likely to vary from time and hence the field density

also. So it is required to report the test result in terms of dry density. The

relationship that can be established between the dry densities with known

moisture content is as follows:-


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Apparatus:-

(1) Cylindrical core cutter of steel, 130 mm. long and 10 cm. internal diameters,

with a wall thickness of 3 mm, beveled at one end.

(2) Steel dolly, 2.5 cm. high and 10 cm. internal diameters, with wall thickness 7.5

mm. fitted with a lip to enable it to be fitted on top of the core cutter.

(3) Steel rammer, having mass of 9 kg.

(4) Palette knife.

(5) Steel rule.

(6) Spade or pickaxe or grafting tool.

(7) Straight edge.

(8) Balance accurate to 1 gm.

(9) Container for water content determination.

Brief procedure:-

(1) Measure the inside dimensions (accurate to 0.25 mm.) of the core cutter and

calculate its volume. Find the mass of the core cutter (without dolly), accurate

to 1 gm.

(2) Expose the small area, about 30 cm. square, to be tested and level it. Put the

dolly on the top of the core cutter and drive the assembly into the soil with help

of the rammer until the ……….of the dolly protrudes about 1.5 cm. above the

surface.

(3) Dig out the container from the surrounding soil, and allow some soil to project

from the …… end of the cutter. With the help of the straight edge, trim flat the

end of the cutter. Take out dolly and also trim flat the other end of the cutter.

(4) Find the mass of cutter full of soil.

(5) Keep some representative specimen of soil for water content determination.

(6) Repeat the test at two or three locations nearby and get the average dry

density.


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Observation Table:-

DATA AND OBSERVATION SHEET FOR DRY DENSITY DETERMINATION BY CORE CUTTER

METHOD

S.NO. DETERMINATION NO. 1 2 3

1 Mass of core cutter + wet soil (g)

2 Mass of core cutter (g)

3 Mass of wet soil (g)

4 Volume of core cutter (g)

5 Bulk density ⍴=m/v (g/cm3)

6 Bulk unit weight Ὑ = 9.81 ⍴ (kN/ m3)

7 Container no.

8 Mass of container + wet soil (g)

9 Mass of container + dry soil (g)

10 Mass of container (g)

11 Mass of dry soil (g)

12 Mass of water

13 Water content (Ratio)

14 Dry density ⍴d=⍴/1+w (g/cm3)

15 Dry unit weight Ὑ d= Ὑ /1+w (kN/ m3)

Result:-

(1) In place bulk density of soil, ⍴= ………………………………….g/cc.

(2) In place dry density of soil, ⍴d=……………………………………… g/cc.

Comments: -


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Remarks:-

Questions:-

CORE CUTTER


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Experiment no.:-9

Object: - DETERMINATION OF FIELD DENSITY BY SAND REPLACEMENT METHOD.

Objective: - Determine the in situ density of natural or compacted soils using sand pouring cylinders.

Need and Scope:-

(1) The in situ density of natural soil is needed for the determination of bearing capacity of soils, for the purpose of stability analysis of slopes, for the determination of pressures on underlying strata for the calculation of settlement and the design of underground structures.

(2) It is very quality control test, where compaction is required, in the cases like embankment and pavement construction.

Standard: - IS: 2720 (Part XXVIII) 1988.

Definition: - The dry density of the soil will be equal to the bulk density divided by

(1+w).

Apparatus:-

(1) Sand pouring cylinder of 3 liter capacity mounted above a pouring cone and separated by a shutter cover plate.

(2) Tools for excavating holes; suitable tools such as scraper tool to make a level surface. (3) Cylindrical calibrating container with an internal diameter of 100 mm. and an internal

depth of 150 mm. fitted with a flange 50 mm. wide and about 5 mm surrounding the open end.

(4) Balance to weigh unto an accuracy of 1g. (5) Metal containers to collect excavated soil. (6) Metal tray with 300 mm. square and 40 mm/50 mm deep with a 100 mm. diameter

hole in the centre. (7) Glass plate about 450 mm. square and 10mm thick. (8) Clean, uniformly graded natural sand passing through 0.600 mm I.S.sieve and

retained on the 300micron I.S.sieve. It shall be free from organic matter and shall have been oven dried and exposed to atmospheric humidity.

(9) Suitable non-corrodible airtight containers. (10) Thermostatically controlled oven with interior on non-corroding material to

maintain the temperature between 1050C to 1100C. (11) A dessicator with any desiccating agent other than sulphuric acid.


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Theory:- By conducting this test it is possible to determine the field density of the soil. The moisture content is likely to vary from time and hence the field density also. So it is required to report the test result in terms of dry density. The relationship that can be established between the dry density with known moisture content is as follows:

Procedure:-

(A) Calibration of the Cylinder:-

(1) Fill the sand pouring cylinder with clean sand so that the level of the sand in the cylinder is within about 10 mm from the top. Find out the initial mass of the cylinder plus sand (M1) and this mass should be maintained constant throughout the test for which the calibration is used.

(2) Allow the sand of volume equal to that of the calibrating container to run out of the cylinder by opening the shutter, close the shutter and place the cylinder on the glass plate open the shutter and allow the send to run out. Close the value when no further movement of sand takes place in the cylinder close the shutter and remove the cylinder carefully. Weigh the sand collected on the glass plate. Its mass (M2) gives the mass of sand filling the cone portion of the sand pouring cylinder.

(3) Repeat this step at least three times and take the mean mass (M2) Put the sand back into the sand pouring cylinder to have the same initial constant mass (M1)

(B) Determination of Bulk Density of Soil:-

(1) Determine the volume (V) of the container be filling it with water to the brim. Check this volume by calculating from the measured internal dimensions of the container.

(2) Place the sand poring cylinder centrally on hype of the calibrating container making sure that constant mass (M1) is maintained. Open the shutter and permit the sand to run into the container. When no further movement of sand is seen close the shutter, remove the pouring cylinder and find its mass (M3).

(C) Determination of Dry Density of Soil in Place:-

(1) Approximately 45 sq/cm of area of soil to be tested should be trimmed down to a level surface, approximately of the size of the container. Keep the metal tray on the


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level surface and excavate a circular hole of volume equal to that of the calibrating container. Collect all the excavated soil in the tray and find out the mass of the excavated soil (Mw). Remove the tray, and place the sand pouring cylinder filled to constant weight so that the base of the cylinder covers the hole concentrically. Open the shutter and permit the sand to run into the hole. Close the shutter when no further movement of the sand is seen. Remove the cylinder and determine its mass (M3).

(2) Keep a representative sample of the excavated sample of the soil for water content determination.

Observation Table:-

DATA AND OBSERVATION SHEET FOR DRY DENSITY DETERMINATION OF DRY

DENSITY BY SAND REPLACEMENT METHOD

S.NO. SAMPLE DETAILS CALIBRATION 1 2 3

(a) Determination of bulk density of sand

(1) Mean Mass of sand in cone (of pouring cylinder) M2 gm.

(2) Volume of calibrating container (V) in cc

(3) Mass of sand + cylinder before pouring M1 gm

(4) Mass of sand + cylinder after pouring M3 gm

(5) Mass of sand to fill calibrating containers Ma = (M1-M3-M2) (gm)

(6) Bulk density of sand s = Ma / V gm/cc

(b) Measurement of soil density

(1) Mass of wet soil from hole Mw gm

(2) Mass of sand + cylinder before pouring M1 gm

(3) Mass of sand + cylinder after pouring M4 gm

(4) Mass of sand in hole Mb = (M1-M2-M4) gm

(5) Bulk density of soil b = (Mw /Mb) s gm/cc

(6) Bulk unit weight of soil = 9.81 b (kN/ m3)

(c) Water content determination

(1) Container number

(2) Mass of wet soil

(3) Mass of dry soil (4) Moisture content (%)

(5) Dry density d = b / (1+w) gm/cc

(6) Dry unit weight d= 9.81 pd (kN/ m3)


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Precautions:-

(1) While calibrating the bulk density of sand great care has to be taken. (2) The excavated hole must be equal to the volume of the calibrating container.

Result:-

(1) In place bulk density of soil, ⍴= ………………………………….g/cc.

(2) In place dry density of soil, ⍴d=……………………………………… g/cc.

Questions:-

SAND REPLACEMENT METHOD

Determination of Density by Sand Replacement Method

Documents

Soil Lab.manual MANOJ