darshan institute of engineering & technology rajkot · fineness with the finest sieve...

D E P A R T M E N T O F C I V I L E N G I N E E R I N G D I E T - R A J K O T

DARSHAN INSTITUTE

OF

ENGINEERING & TECHNOLOGY

RAJKOT

GEOTECHNICS & APPLIED GEOLOGY

LAB MANUAL - 2130606

DEGREE CIVIL ENGINEERING

SEMESTER – III

Name of student

Roll No.

Enrollment No.

A.Y.

Department of Civil Engineering

Geotechnical Engineering Laboratory

Darshan Institute of Engineering and Technology-Rajkot.

This is to certify that Mr. /Miss.___________________________________________

Of B.E. (3rd Semester-Civil), Enrolment No________________________________

has satisfactorily completed his/her term work in the subject of Geotechnics & Applied

Geology (2130606) for the Academic year____________ in this institute.

Submission Date:_____________

Faculty sign Head of Department

D E P A R T M E N T O F C I V I L E N G I N E E R I N G D I E T - R A J K O T

INDEX

Sr.

No. Name of Experiment

Page

No. Date Sign.

1. Determination of Specific Gravity of Soil 1

2. Determination of Particle Size Distribution (Soil) 4

3. Determination of Grain Size Distribution By Hydrometer

8

4. Determination of Liquid Limit & Plastic Limit of Soil

14

5. Determination of Shrinkage Limit of Soil 19

6. In Situ Density-Core Cutter and Sand Replacement

23

7. Determination of Permeability of Soil 28

Geotechnics and Applied Geology (2130606)

Experiment-1 Determination of Specific Gravity of Soil

1 | P a g e D I E T - R a j k o t

SCOPE:

Determination of the specific gravity of fine soil.

APPARATUS:

• Two density bottles (Pycnometer) of approximately 50 ml capacity with stoppers.

• A water-bath maintained at a constant temperature to within ± 0.20C (If standard density bottles are used,

this constant temperature is 270 C.)

• A vacuum desiccator (a convenient size is one about 200 mm to 250 mm in diameter).

A desiccator (a convenient size is one about 200 mm to 250 mm in diameter) containing anhydrous silica

gel. A thermostatically controlled drying oven, capable of maintaining a temperature of 105 to 110oC. • A balance readable and accurate to 0.001 g.

• A source of vacuum, such as a good filter pump or a vacuum pump.

• A spatula (a convenient size is one having a blade 150 mm long and 3 mm wide; the blade has to be small

enough to go through the neck of the density bottle), or piece of glass rod about 150 mm long and 3 mm

diameter.

• A wash bottle, preferably made of plastics, containing air-free distilled water.

• A sample divider of the multiple slot type (riffle box) with 7 mm width of opening

• A length of rubber tubing to fit the vacuum pump and the desiccator.

Density bottle (Specific Gravity bottle) Specific gravity Determination




PROCEDURES:

1. The complete density bottle with stopper shall be dried at 105 to 110°C, cooled in the desiccator and

weighed to the nearest 0.001 g (m1).

2. The 50 g sample obtained as described in the procedure for the preparation of disturbed samples for

testing shall, if necessary, be ground to pass a 2-mm IS test sieve.

3. A 5 to 10 g subsample shall be obtained by riffling, and oven-dried at 105 to 1100 C.

4. This sample shall be transferred to the density bottle direct from the desiccator in which it has been

cooled.

5. The bottle and contents together with the stopper shall be weighed to the nearest 0.001 g (m2).

6. The stoppered bottle shall then be taken out of the bath, wiped dry and the whole weighed to the nearest

0.001 g (m3).

7. The bottle shall then be taken out of the bath, wiped dry and the whole weighed to the nearest 0.001 g

(m4)

8. Two determinations of the specific gravity of the same soils sample shall be made.

CALCULATION:

The specific gravity of the soil particles G shall be measured at room temperature. If water has been used as

the air-free liquid, then the following equation shall be used

G = (𝑀2−𝑀1)

(𝑀4−𝑀1)−(𝑀3−𝑀2)

M1 = mass of density bottle in g

M2 = mass of bottle and dry soil in g

M3 = mass of bottle, soil and liquid in g and

M4 = mass of bottle when full of liquid only in g.




REPORTING OF RESULTS:

The average of the values obtained shall be taken as the specific gravity of the soil particles and shall be

reported to the nearest 0.01. If the two results differ by more than 0.03, the tests shall be repeated.

Test No. 1 2 3

Pycnometer /density bottle no

Mass of Pycnometer bottle M1 (g)

Mass of Pycnometer +dry soil, M2(g)

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

Mass of Pycnometer +water M4(g)

Specific gravity=(M2−M1)

(M4−M1)−(M3−M2)

Conclusion:


Experiment-2 Determination Of Particle Size Distribution (Soil)


SCOPE:

This standard (Part 4) covers the method for the quantitative determination of grain size distribution in soils.

APPARATUS:

Balance: Sensitive to 0.1 percent of the weight of sample to be weighed.

Sieves: 100-mm IS Sieve, 75-mm IS Sieve, 19-mm IS Sieve and 4.75-mm to 75 µ IS Sieve conforming to the

requirement of IS: 460 (Part I)-1978.

Rubber Pestle and Mot-tat

Trays or Bucket - two or more large metal or plastic watertight trays or a bucket about 30 cm in diameter and

30 cm deep (convenient sizes of the trays are in the range of 45 to 90 cm2 and 8 to 15 cm deep).

Brushes - sieve brushes and a wire brush or similar stiff brush.

Mortar with a Rubber Covered Pestle

Mechanical Sieve Shaker (Optional)

Riffle

IS Sieve Sieve Analysis




PREPARATION OF SAMPLE:

• The soil sample received from the field shall be prepared as-specified in IS: 2720 (Part I)-1983. The soil

fractions retained on and passing 4.75-mm IS Sieve shall be taken separately for the analysis.

Maximum Size of Material

Present In Substantial

Quantities in (mm)

Mass to be

taken for test in

(kg)

75 60 40 25 25 13 19 6.5

12.5 3.5 10 1.5 6.5 0.75 4.75 0.4

PROCEDURE: • Analysis by Wet Sieving - The portion of the soil passing 4.75-mm IS Sieve obtained as given in shall be

oven-dried at 105 to 110°C. The oven-dried material shall then be riffled so that a fraction of convenient

mass is obtained. This shall be about 200 g if a substantial proportion of the material only, just passes the

4.75-mm IS Sieve or less if the largest size is smaller. The fraction shall be weighed to 0. 1 percent of its

total mass and the mass recorded. The riffled and weighed fraction shall be spread out in the large tray or

bucket and covered with water.

• Two grams of sodium hexametaphosphate or one gram of sodium hydroxide and one gram of sodium

carbonate per liter of water used should then be added to the soil. The mix should be thoroughly stirred

and left for soaking.

• The soil soaked specimen should be washed thoroughly over the nest of sieves, nested in order of their

fineness with the finest sieve (75-micron IS Sieve) at the bottom. Washing shall be continued until the

water passing each sieve is substantially clean. Care shall be taken to see that the sieves are not overloaded

in the process.

• The fraction retained on each sieve should be emptied carefully without any loss of material in separate

trays. Oven dried at 105 to 110°C and each fraction weighed separately and the masses recorded.

• Alternatively, the soaked soil specimen may be washed on the 75-micron IS Sieve until the water passing

the sieve is substantially clean. The fraction retained on the sieve should be tipped without loss of material




in a tray, dried in the oven and sieved through the nest of sieves, either by hand or by using mechanical

sieve shaker. The fraction retained on each sieve should be weighed separately and the masses recorded.

FROM FOR THE RECORED OF RESULT OF GRAIN SIZE ANALYSIS

Sieve size

(mm)

Soil retained

(g)

Percent retained (%)

Cumulative percent retained

(%)

Percent finer

4.75 mm

2.00 mm

1.00 mm

600 micron

425 micron

300 micron

212 micron

150 micron

75 micron

Pan




Make a grain size distribution curve by plotting sieve size on log scale and percent finer on ordinary scale.

Read off the sizes corresponding to 60%, 30% and 10% finer. Calculate the uniformity coefficient (Cu) and the curvature coefficient (Cc) for the soil.

Draw chart % passing v/s Sieve size and find the particle size as below Find D60 =_________________mm D30 =_________________mm D10 =_________________mm Calculate

Cu = D60 / D10 = _________________ Cc = (D30)2 /( D60 * D10 ) =_________________

Result

Particle type % Silt and Clay Sand Gravel


Experiment-3 Determination Of Grain Size Distribution By Hydrometer


OBJECTIVE The object of this experiment is to determine the distribution of particle size, finer than 75-micron sieve, by

sedimentation analysis, using a density hydrometer, and then to plot the grain size distribution curve.

APPARATUS

Density hydrometer conforming to IS : 3104-1965, (ii) Two glass measuring cylinders of 1000 ml capacity

with ground glass or rubber stoppers about 7 cm diameter and 33 cm high marked at 1000 ml volume, (iii)

Thermometer to cover the range 0 to 50⁰C, accurate to 0.50 ⁰C, (iv) water bath or constant temperature room

(optional), (v) stirring apparatus, (vi) 75 micron sieve, (vii) balance accurate to 0.01 g, (viii) stop watch, (ix)

wash bottles containing distilled water, (x) glass rod, about 15 to 20 cm long and 4 to 5 mm in diameter, (xi)

reagents : hydrogen peroxide, hydrochloric acid N solution and sodium hexametaphosphate, (xii) conical flask

of 1000 ml capacity, (xiii) Buchner of Hirch funnel, (xiv) filter flask, (xv) measuring cylinder of 100 ml

capacity, (xvi) filter paper and blue litmus paper.

Hydrometer




PROCEDURES:

(A) CALIBRATION OF HYDROMETER

1. Determination of volume of the hydrometer bulb (Vh). Pour about 800 ml of water in the 1000 ml

measuring cylinder and note the reading at the water level. Immerse the hydrometer in water and

note the water reading. The difference between the two readings is recorded as the volume of the

hydrometer bulb plus the volume of that part of the stem which is submerged. For practical

purposes, the error due to the inclusion of this stem volume may be neglected. Alternatively, weigh

the hydrometer to the nearest 0.2 g. This mass in grams is recorded as the volume of the

hydrometer in ml. This includes the volume of the bulb plus the volume of the stem. For practical

purposes the error due to the inclusion of the stem may be neglected.

2. In order to find the area of cross-section (A) of the measuring cylinder in which the hydrometer

is to be used, measure the distance, in cm, between two graduations of the cylinder. The cross-

sectional area (A) is then equal to the volume included the two graduations divided by the distance

between them.

3. Measure the distance (h) from the neck to the bottom of the bulb, and record it as the height of

the bulb.

4. With the help of an accurate scale, measure the height H between the neck of the hydrometer to

each of the other major calibration marks (Rh).

5. Calculate the effective depthe (He) corresponding to each of the major calibration marks by the

following equation : He=H+1/2(h-Vh/a)

6. The readings may be recorded as illustrated in Table.

7. Draw a calibration curve between He and Rh which may be used for finding the effective depth

(He) corresponding to hydrometer readings (Rh) obtained during the test.

8. Meniscus correction. Insert the hydrometer in the measuring cylinder containing about 700 ml of

water. Take the readings of the hydrometer at the top and bottom of the meniscus. The difference

between two readings is taken as the meniscus correction (Cm) which is a constant for a

hydrometer. During the actual sedimentation test, the readings should be taken at the bottom of

the meniscus but since the soil suspension is opaque, readings are taken at the top of meniscus. It

is clear from figure that readings decrease in the upward direction. Thus the observed hydrometer

readings is always less than the true one. Hence the meniscus correction is always positive.




(B) PRE-TREATMENT OF SOIL

1. Weigh accurately 50 to 100 gm of oven-dried soil sample (Md) passing the 2 mm IS sieve. If the

percentage of soluble salts is more than one per cent, the soil should be washed with water before

further treatment, taking care to see that the soil particles are not lost.

2. Add 150 ml of hydrogen peroxide to the soil sample placed in a wide mouth conical flask and stir

it gently for few minutes with a glass rod. Cover the flask with glass and level it to stand overnight.

3. Next morning, the mixture in the conical flask is gently heated in an evaporating dish, stirring the

contents periodically. Reduce the volume to about 50 ml by boiling. With very organic soils

additional peroxide may be required to complete the oxidation.

4. If the soil contains insoluble calcium compounds, add about 50 ml of hydrochloric acid to the

cooled mixture of soil obtained in step 3. The solution is stirred with a glass rod for a few minutes

and allowed to stand for one hour or for longer periods, if necessary.

5. Filter the mixture and wash it with warm water until the filtrate shows no acid reaction to litmus.

Transfer the damp soil on the filter paper and funnel to the evaporating dish using a jet of distilled

water. Place the dish and its contents to the oven. Take the mass (Md) of the oven-dried soil

remaining after pre-treatment and find the loss of mass due to pre-treatment. Note. In case of soils

containing no calcium compounds or soluble salts having a low organic content the pre-treatment

prescribed above may be omitted and the dispersing agent is added direct to the soil taken for

analysis.

(C) DISPERSION OF SOIL

1. To the oven-dried soil in the evaporating dish, and 100 ml of sodium hexametaphosphate solution

and warm the mixture gently for about 10 minutes. Transfer the mixture to the cup of the

mechanical mixer using a jet distilled water, and stir it well for about 15 minutes. The sodium

hexametaphosphate solution is prepared by dissolving 33 g of sodium hexametaphosphate and

seven grams of sodium carbonate in distilled water to make one litre of solution. This solution is

unstable and should be freshly prepared approximately once in a month.

2. Transfer the soil suspension to the 75 micron IS sieve placed on a receiver and washes the soil on

this sieve using jet of distilled water from a wash bottle. The amount of distilled water used during

this operation may be about 500 ml.

3. Transfer the soil suspension passing the 75 micron IS sieve to the 1000 ml measuring cylinder,

and adds more distilled water to make the volume to exactly 1000 ml in the cylinder.




4. Collect the material retained on 75 micron sieve and put it in the oven for drying. Determine the

dry mass of soil retained on 75 micron sieve.

(D) SEDIMENTATION TEST WITH HYDROMETER

1. Insert a rubber bung or any other suitable cover on the top of the 1000 ml measuring cylinder

containing the soil suspension and shake it vigorously end over end. Stop shaking and allow it to

stand. Immediately, start the stop watch, and remove the top cover from the cylinder.

2. Immerse the hydrometer gently to a depth slightly below its floating position and then allow it to

float freely. Take the hydrometer readings after periods of ½, 1, 2 and 4 minutes. Take out the

hydrometer, rinse it with distilled water and allow it to stand in a jar containing distilled water at

the same temperature as that of the test cylinder.

3. The hydrometer is re-inserted in the suspension and readings are taken after periods of 8, 15 and

30 minutes; 1, 2 and 4 hours after shaking. The hydrometer should be removed, rinsed and placed

in the distilled water after each reading. After the end of 4 hours, readings should be taken once

or twice within 24 hours.

4. Composite correction. In order to determine the composite correction, put 100 ml of dispersing

agent solution in another 1000 ml measure ing cylinder and make it to 1000 ml by adding distilled

water. The cylinder should be maintained at the same temperature as that of the test cylinder

containing soil specimen. Insert the hydrometer in this comparison cylinder containing distilled

water and the dispersing agent and take the reading corresponding to the top of the meniscus. The

negative of the hydrometer reading so obtained gives the composite correction (C). The composite

correction is found before the start of the test, and also at every time intervals of 30 minutes, 1

hour, 2 hours and 4 hours after the beginning of the test, and afterwards, just after each hydrometer

reading is taken in test cylinder.

5. The temperature of the suspension should be observed and recorded once during the first 15

minutes and then after every subsequent reading.

Tabulation of observations.

The test observations and results are recorded as illustrated in Table. The observation for the

calibration of the hydrometer have been recorded in Table.

Particle size distribution curve.

The results of the above table are plotted to get a particle size distribution curve with percentage

finer N as the ordinate and the particle diameter (D) on logarithmic scale as abscissa.




Calculations. 1. The loss in mass in pre-treatment of the soil in percentage is calculated from the following

expression :

P= (1 −𝑀𝑏

𝑀𝑑)*100

Where,

P = loss in mass in percentage

Mb = mass of dry soil sample taken from the soil passing 2 mm sieve

Md = mass of the soil after pre-treatment.

2. The diatmeter of the particles in suspension at any sampling time t is calculated from Eq. D=10-

5 F√𝐻𝑒/𝑡 : , where factor F is taken either from Table.

3. The percentage finer N’ based on the mass Md is calculated from Eq.

N’ =1000𝐺

𝑀𝑑(𝐺 − 1)∗ 𝑅

4. The percentage finer N based on total mass of dry soil sample sample (M) is obtained from the relation :

N = N′ ∗𝑀′

𝑀

Where M’ = cumulative mass passing 2 mm sieve

Table Data and observation sheet for hydrometer analysis

1. Sample No.

2. Mass of dry soil sample (M) = 500 g

3. Mass of fraction passing 2 mm sieve (M’) = 500 g

4. Mass of dry sample taken from minus 2 mm sieve (Md) = 50 g

5. Specific gravity of soil particles from minus 75 micron: G = 2.67

6. Hydrometer no. : Sedimentation jar no. ; Meniscus correction: Cm = +0.5




Dat

e

Tim

e

Ela

psed

Tim

e in

Min

. (t)

Hyd

rom

eter

R

eadi

ng (

Rh’)

Tem

p 0 C

Cor

rect

ion

C

Rh

=R

h’+

Cm

Eff

ecti

ve d

epth

in

cm

(H

e)

Fac

tor

F

Par

ticl

e S

ize

in

mm

(D

)

R=

Rh’+

C

% Finer based on Md

(N’)

% Finer based on Whole N=

N’ X 𝑀′

𝑀

The uniformity coefficient Cu and coefficient of curvature Cc are calculated respectively as

per equation Note

1) Specific gravity G should be determined for the fraction of the sample passing 75 micron sieve.

2) For highly flocculated soil use N-Sodium hydroxide solution as a dispersing agent at the rate of

4 ml per 10 g of soil in place of sodium hexametaphosphate.


Experiment-4 Determination Of Liquid Limit & Plastic Limit Of Soil

1 4 | P a g e D I E T - R a j k o t

SCOPE

Determination of the liquid limit and plastic limit of soils by mechanical method.

DETERMINATION OF LIQUID LIMIT

APPARATUS

Mechanical Liquid Limit Device - It shall conform to IS: 9259-1979.

Grooving Too-It shall conform to IS: 9259- 1979.

Porcelain Evaporating Dish - about 12 to 15 cm in diameter.

Flat Glass Plate-10 mm thick and about 45 cm square or larger (alternative to porcelain evaporating dish for

mixing soil with water).

Spatula-flexible, with the blade about 8 cm long and 2 cm wide (for mixing soil and water in the porcelain

evaporating dish).

Palette Knives-two, with the blade about 20 cm long and 3 cm wide (for mixing soil and water on the flat

glass plate).

Balance-sensitive to 0.01 g.

Oven-thermostatically controlled with interior of non-corroding material to maintain the temperature between

105 and 110°C.

Wash Bottle or Beaker-containing distilled water Containers-air-tight and non-corrodible for

determination of moisture content.

Liquid limit Appartus Filling Paste




Making Grove Grove Measurment

SOIL SAMPLE A sample weighing about 120 g shall be taken from the thoroughly mixed portion of material passing 425-

micron IS Sieve is IS: 460 (Part I)-19781 obtained in accordance with IS: 2720 (Part I)-1983.

PROCEDURE 1. About 120 g of the soil sample passing 425-micron IS Sieve shall be mixed thoroughly with distilled

water in the evaporating dish or on the flat glass to form a uniform paste. The paste shall have a

consistency that will require 30 to 35 drops of the cup to cause the required closure of the standard

groove. In the case of clayey soils, the soil paste shall be left to stand for a sufficient time (24 hours)

so as to ensure uniform distribution of moisture throughout the soil mass.

2. The soil should then be re-mixed thoroughly before the test. A portion of the paste shall be placed in

the cup above the spot where the cup rests on the base, squeezed down and spread into position, with

as few strokes of the spatula as possible and at the same time trimmed.

3. A depth of one centimeter at the point of maximum thickness, returning the excess soil to the dish. The

soil in the cup shall be decided by firm strokes of the grooving tool along the diameter through the

center line of the cam follower so that a clean, sharp groove of the proper dimensions is formed. In

case where grooving tool, Type A does not give a clear groove as in sandy soils, grooving tool Type

B or Type C should be used.




4. The cup shall be fitted and dropped by turning the crank at the rate of two revolutions per second until

the two halves of the soil cake come in contact with bottom of the groove along.a distance of about 12

mm. This length shall be measured with ‘the end of the grooving tool or a ruler. The number of drops

required to cause the grove close for the length of 12 mm shall be recorded. A little extra of the soil

mixture shall be added to the cup and mixed with the soil in the cup. The pat shall be made in the cup

and the test repeated.

5. In no case shall dried soil be added to the thoroughly mixed soil that is being tested and in, this clause

shall be repeated until two consecutive runs give the same under of drops for closure of the groove.

6. A representative slice of soil approximately the width of the spatula, extending from about edge to

edge of the soil cake at right angle to the groove and including that portion of the groove in which the

soil flowed together. Shall be taken in a suitable container and its moisture content expressed as a

percentage of the oven-dry weight otherwise determined as described in IS: 2720 (Part 2)-1973. The

remaining soil in the cup shall be transferred to the evaporating dish and the cup and the grooving tool

cleaned thoroughly.

7. The operations shall be repeated for at least three more additional trials (minimum of four in all), with

the soil collected in the evaporating dish or flat glass plate, to which sufficient water has been added

to bring the soil to a more fluid condition. In each case, the number of blows shall be recorded and the

moisture content determined as before. The specimens shall be of such consistency that the number of

drops required to close the groove shall be not less than 15 or not more than 35 and the points on the

flow curve are evenly distributed in this range. The test should proceed from the drier (more drops) to

the wetter (less drops) condition of the soil. The test may also be conducted from the wetter to the drier

condition provided drying is achieved by kneading the wet soil and not by adding dry soil.

Determination of Liquid Limit:

Liquid Limit (WL):

A flow curve ‘shall be plotted on semi-logarithmic graph representing water content on the arithmetical scale

and the number of drops on the logarithmic scale. The flow curve is a straight line drawn as nearly as possible

through the four or more plotted points. The moisture content corresponding to 25 drops as read from the

curve shall be rounded off to the nearest whole number and reported as the liquid limit of the soil.




DETERMINATION OF PLASTIC LIMIT

APPARATUS

Porcelain Evaporating Dish about 12 cm in diameter.

Flat Glass Plate - 10 mm thick and about 45 cm square or larger. Spatula - flexible, with the blade about 8 cm long and 2 cm wide.

or

Palate Knives-two, with the blade about 20cm long and 3 cm wide (for use with flat glass plate for mixing

soil and water).

Surface for Rolling - ground-glass plate 20 × 15cm.

Containers - air-tight to determine moisture content.

Balance - sensitive to 0.01 g.

Oven - thermostatically controlled with interior of noncorroding material to maintain the temperature

between 105 and 110 ̊ C.

Rod-3 mm in diameter and about 110 cm long.

Determination of Plastic Limit Crumbed Sample

Soil Sample - A sample weighing about 20 g from the thoroughly mixed portion of the material passing

425-micron IS Sieve, obtained in accordance with IS -2720 (Part l)-1983 shall be taken




REPORT

The observations of the test should be recorded suitably.

The moisture content determined as is the plastic limit of the soil.

The plastic limit shall be determined for at least three portions of the soil passing 425-micron IS Sieve.

The average of the results calculated to the nearest whole number shall be reported as the plastic limit

of the soil.

PROFOMA FOR TESTS AND CALCULATIONS OF LIQUID LIMIT AND PLASTIC LIMIT

Liquid limit Plastic limit

Determination

number 1 2 3 4 5 1 2 3 4

Number of drop - - - -

Container number

Container Weight

Weight of cont. +

wet soil, g

Weight of cont. +

oven dry soil, g

Weight of water

Weight of oven

dry sample

Moisture content

RESULT SUMMARY

Liquid

limit

WL

Flow

Index

IF

Plastic

limit

Wp

Plasticity

index

IP=WL-WP

Toughness

index

It=IP/IF

Liquidity

index

IL=(W-WP)/IP

Consistency

index

IC=(WL-W)/IP


Experiment-5 Determination Of Shrinkage Limit Of Soil


OBJECTIVE

To determine the shrinkage limit and calculate the shrinkage ratio for the given soil.

THEORY As the soil loses moisture, either in its natural environment, or by artificial means in laboratory it changes

from liquid state to plastic state, from plastic state to semi-solid state and then to solid state. Volume changes

also occur with changes in water content. But there is particular limit at which any moisture change does not

cause soil any volume change.

NEED AND SCOPE

Soils which undergo large volume changes with change in water content may be troublesome. Volume

changes may not and usually will not be equal.

A shrinkage limit test should be performed on a soil.

1. To obtain a quantitative indication of how much change in moisture can occur before any appreciable

volume changes occurs

2. To obtain an indication of change in volume.

The shrinkage limit is useful in areas where soils undergo large volume changes when going through wet and dry cycles (as in case of earth dams) APPARATUS

1. Evaporating Dish. Porcelain, about 12cm diameter with flat bottom. 2. Spatula 3. Shrinkage Dish. Circular, porcelain or non-corroding metal dish (3 nos) having a flat bottom and 45

mm in diameter and 15 mm in height internally. 4. Straight Edge. Steel, 15 cmm in length. 5. Glass cup. 50 to 55 mm in diameter and 25 mm in height, the top rim of which is ground smooth and

level. 6. Glass plates. Two, each 75 75 mm one plate shall be of plain glass and the other shall have prongs. 7. Sieves. 2mm and 425- micron IS sieves. 8. Oven-thermostatically controlled. 9. Graduate-Glass, having a capacity of 25 ml and graduated to 0.2 ml and 100 cc one mark flask. 10. Balance-Sensitive to 0.01 g minimum. 11. Mercury. Clean, sufficient to fill the glass cup to over flowing 12.Wash bottle containing distilled

water.




Shrinkage Limit Appratus Determination of Shrinkage Limit

PROCEDURE Preparation of soil paste

1. Take about 100 gm of soil sample from a thoroughly mixed portion of the material passing through

425-micron I.S. sieve.

2. Place about 30 gm the above soil sample in the evaporating dish and thoroughly mixed with distilled

water and make a creamy paste.

Use water content somewhere around the liquid limit.

Filling the shrinkage dish

3. Coat the inside of the shrinkage dish with a thin layer of Vaseline to prevent the soil sticking to the

dish.

4. Fill the dish in three layers by placing approximately 1/3 rd of the amount of wet soil with the help of

spatula. Tap the dish gently on a firm base until the soil flows over the edges and no apparent air

bubbles exist. Repeat this process for 2nd and 3rd layers also till the dish is completely filled with the

wet soil. Strike off the excess soil and make the top of the dish smooth. Wipe off all the soil adhering

to the outside of the dish.

5. Weigh immediately, the dish with wet soil and record the weight.

6. Air- dry the wet soil cake for 6 to 8hrs, until the color of the pat turns from dark to light. Then oven-

dry the to constant weight at 1050C to 1100C say about 12 to 16 hrs.

7. Remove the dried disk of the soil from oven. Cool it in a desiccators. Then obtain the weight of the

dish with dry sample.

8. Determine the weight of the empty dish and record.

9. Determine the volume of shrinkage dish which is evidently equal to volume of the wet soil as follows.

Place the shrinkage dish in an evaporating dish and fill the dish with mercury till it overflows slightly.




Press it with plain glass plate firmly on its top to remove excess mercury. Pour the mercury from the

shrinkage dish into a measuring jar and find the volume of the shrinkage dish directly. Record this

volume as the volume of the wet soil pat.

Volume of the Dry Soil Pat

10. Determine the volume of dry soil pat by removing the pat from the shrinkage dish and immersing it in

the glass cup full of mercury in the following manner.

Place the glass cup in a larger one and fill the glass cup to overflowing with mercury. Remove the

excess mercury by covering the cup with glass plate with prongs and pressing it. See that no air bubbles

are entrapped. Wipe out the outside of the glass cup to remove the adhering mercury. Then, place it in

another larger dish, which is, clean and empty carefully.

Place the dry soil pat on the mercury. It floats submerge it with the pronged glass plate which is again

made flush with top of the cup. The mercury spills over into the larger plate. Pour the mercury that is

displayed by the soil pat into the measuring jar and find the volume of the soil pat directly.

CALCULATION First determine moisture contain Shrinkage limit Ws ={ W-(V-V0)-

𝛄𝐰

𝑾𝟎 }

Where, W = Moisture content of pat (%)

V = Volume of wet soil pat in cm3

V0 = Volume of dry soil pat in cm3

W0 = Weight of even dry soil pat in g

CAUTION Do not touch the mercury with gold rings.




Table For Determination of Shrinkage Limit

Sr.No Determination No. 1 2 3

1 Wt. of container in g W1

2 Wt. of container +wet of soil pet in g (W2)

3 Wt. of container +dry of soil pat in g (W2)

4 Wt. of oven dry soil pat in g (W0)

5 Wt. of water

6 Moisture content (W %)

7 Volume of wet soil pat in cm3

8 Volume of dry soil pat in cm3

By Mercury displacement method

a.Weight of displaced Mercury

b. Specific gravity of Mercury

9 Shrinkage limit(Ws)

10 Shrinkage Ratio (R)


Experiment-6 In Situ Density-Core Cutter and Sand Replacement


CORE CUTTER METHOD

OBJECTIVE

Determination of the in-situ density of soils by core cutter method.

APPARATUS

Cylindrical core cutter, Dolly, Rammer, Balance (1 g accuracy), Spade, Straight edge knife, Sample extruder, Apparatus for moisture content determination.

Core Cutter

In situ density of soil Leveling the sample




PROCEDURE

1. Measure the internal dimensions of the core cutter and weigh it.

2. Clean and level the site surface where the field density is to be determined.

3. Place the dolly on the cutter and press both into the soil using the rammer until only about 15 mm of the dolly protrudes above the surrounding soil surface.

4. Remove the soil around the cutter with the spade, lift up the cutter, and trim carefully the top and bottom surfaces of the soil sample.

5. Clean the outside surface of the cutter and weigh it with the soil.

6. Remove the soil core from the cutter and take three representative samples in moisture cans for water content determination.

OBSERVATIONS

Internal diameter of core cutter, (cm) = ______________

Height of cutter, (cm) =______________

Volume of cutter, V (cm3) =______________

OBSERVATION TABLE

Test No. 1 2 3

Mass of core cutter (g), W1

Mass of cutter + soil (g), W2

Mass of moist soil (g), (W2- W1)

Average water content, W (%)

Field bulk density (g/cm3),

Field dry density (g/cm3),

In-situ dry density (Average of the computed values)




SAND REPLACEMENT METHOD

NEED AND SCOPE

For hard and gravelly soils, the core-cutter method is not suitable. In its place, sand replacement method can be used, and it involves making a hole in the ground, weighing the excavated soil and determining the volume of the hole.

APPARATUS Sand pouring cylinder, Calibrating cylinder, Clean and dry sand, Metal tray with a central circular hole, Balance (1 g accuracy), Glass plate, Trowel, Scraper tool, Apparatus for moisture content determination.

Calibration cylinder, sand pouring cylinder, Metal Container

Excavation of soil Sand replacement




PROCEDURE

1. An inverted cone forms the base of the sand pouring cylinder, and a shutter at the cone tip controls the release of sand through a uniform free fall.

2. First determine the bulk density of the sand to be used in the field. For this, measure the internal dimensions of the calibrating cylinder so as to obtain its volume. Fill the pouring cylinder with sand and weigh. Place it concentrically on top of the calibrating cylinder, and allow sand to run out and fill both the calibrating cylinder and the inverted conical portion.

3. To obtain only the mass of sand filling up the conical portion, lift the pouring cylinder and then weigh with remaining sand. Place it on a glass plate, and allow sand to run out. Weigh again the pouring cylinder with left over sand.

4. Calculate the mass of sand that fills up the calibrating cylinder, and from its known volume, work out the bulk density of the sand for the allowed free fall.

5. Clean and level the site surface, and place the square tray with a central hole. Excavate a hole of diameter equal to that of the tray hole and depth equal to about 15 cm. Collect the excavated soil in the tray, weigh and then take representative samples for water content determination.

6. Fill the pouring cylinder with the same sand, place it concentrically over the hole, open the shutter and allow sand to fill up the hole.

7. When there is no further movement of sand, close the shutter, remove the cylinder and weigh it with the remaining sand.

OBSERVATIONS

Bulk density of sand (g/cm3) = ______________

Volume of calibrating cylinder (cm3) V1 = ______________

Mass of sand for filling the calibrating cylinder and cone (g), W1 = ______________

Mass of sand for filling only the cone (g), W2 = ______________

Mass of sand in the calibrating cylinder (g), W3 = W1 - W2 =______________




OBSERVATION TABLE

Field Test No. 1 2 3

Mass of pouring cylinder + sand before pouring in hole (g), W4

Mass of pouring cylinder + sand after pouring in hole (g), W5

Mass of sand used in the hole (g), W6 = W4 - W5 - W2

Volume of excavated hole (cm3),

Mass of excavated soil (g), W

Average water content, w (%)

Field bulk density (g/cm3),

Field dry density (g/cm3),

Conclusion


Experiment-7 Determination Of Permeability Of Soil


CONSTANT HEAD METHOD

OBJECTIVE

Determination of the coefficient of permeability of a soil using constant head apparatus

APPARATUS Permeameter mould and accessories, Circular filter papers, Compaction device, Constant head reservoir, Measuring flask, Stop-watch

Constant Head Permeability Test

Mould




PROCEDURE

1. Take 2.5 kg of dry soil and prepare it to obtain desired water content.

2. Apply little grease on to the interior sides of the permeameter mould.

3. 3. Keep a solid metal plate in the groove of the compaction base plate. Assemble the base plate, mould

and collar. Compact the soil into the mould.

4. 4. Remove the collar and base plate, and replace the solid metal plate with a porous stone covered with

filter paper.

5. 5. Trim off excess soil from the top of the mould and place another porous stone with filter paper on

it. Attach the top cap of the permeameter.

6. 6. Connect a constant head reservoir to the bottom outlet of the mould. Open the air vent of the top

cap, and allow water to flow in and upwards till the soil gets saturated.

7. 7. Disconnect the reservoir from the bottom outlet and connect it to the top inlet. Close the air vent and

allow water to establish a steady flow.

8. 8. Collect the water in a measuring flask for a convenient time interval. For similar time intervals,

measure the flow quantity for at least three times.

9. 9. After the test, measure the temperature of the water.

GENERAL DATA Diameter of sample D (cm) =_______________

Length of sample L (cm) =_______________

Area of sample A (cm2) =_______________

Volume of sample V (cm3) =_______________

Initial mass of sample W (g) =_______________

Initial water content w (%) =_______________

Moulding density (g/cm3) =_______________




OBSERVATION TABLE

Sr.No Quantity of water collected (Q) ml

Duration (t) second

Constant head h (cm)

i = h / L k= 𝑸

𝒕∗

𝟏

𝒊.𝑨

Conclusion (constant head):




VARIABLE HEAD TEST

OBJECTIVE Determination of the coefficient of permeability of a soil using variable head apparatus.

APPARATUS Permeameter mould and accessories, Circular filter papers, Compaction device, Graduated glass standpipes along with support frame and clamps, Measuring flask, Stop-watch.

Falling Head Permeability Test

PROCEDURE

1. Follow the same steps 1 to 6 as for the constant head test.

2. Disconnect the reservoir from the bottom outlet and connect a selected standpipe to the top inlet.

3. Fill the standpipe with water, close the air vent and allow water to flow.




4. Open the bottom outlet and record the time interval required for the water surface in the standpipe to

fall between two levels as measured from the center of the outlet.

5. Measure time intervals for similar drops in head at least three times after re-filling the standpipe.

6. At the end of the test, measure the temperature of the water.

OBSERVATION TABLE

Diameter of standpipe, d(cm) =_______________

Cross-sectional area of standpipe a (cm2) =_______________

Test No. 1 2 3

Initial head, h1 (cm)

Final head , h2 (cm)

Time interval in seconds, ( t2 - t1)

Coefficient of permeability (cm/sec)

Conclusion (variable head):

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