soil laboratory testing report by a k jha-libre

INDIANINSTITUTEOFSCIENCE(IISc)DEPARTMENTOFCIVILENGINEERING

GEOTECHNICALENGINEERINGBANGALORE,INDIA

LAB REPORT ON SOIL EXPLORATION AND TESTING

.

Submitted By: Submitted To:

Arvind Kumar Jha Dr. P. Anbazhaghan Ph. D. Student Department of Civil Engineering

SR. NO.: 07-05-00-90-12-12-1-09649 Indian Institute of Science, Bangalore

Geotechnical Engineering

Prepared By: Arvind Kumar Jha



LAB REPORT

ON

SPECIFIC GRAVITY OF FINE GRAINED SOIL BY DENSITY BOTTLE

METHOD



Geotechnical Engineering Indian Institute of Science, Bangalore

16th August, 2012

1 Lab Report on Determination of Specific Gravity of Fine grained soil


NAME OF TEST: TO DETERMINE SPECIFIC GRAVITY OF FINE GRAINED SOIL BY DENSITY BOTTLE METHOD.

APPARATUS REQUIRED: a) Five density bottles of 50 ml capacity with stoppers.

b) Oven (105o to 110

oC)

c) Vacuum desiccator fitted with rubber tube.

d) Source of vacuum or vacuum pump.

e) A balance readable and accurate to 0.001g.

f) Spatula (150mm length and 3mm width )

g) Constant temperature bath of temperature 27oC 0.2

oC.

h) Thermometer

THEORY:

This test is done to determine the specific gravity of fine-grained soil by density bottle method as

per IS: 2720 (Part 3/Sec 1) 1980 (Reaffirmed 1987).

Specific gravity is the ratio of the weight in air of a given volume of a material at a standard

temperature to the weight in air of an equal volume of distilled water at the same stated

temperature. The specific gravity is used to find out the degree of saturation and unit weight of

moist soil. Ultimately the unit weight of soil is used to determine pressure, settlement and

stability problem.

It is determined in the laboratory by using following formula:

..... (I)

Where

m1 = mass of density bottle in gm;

m2 = mass of bottle and dry soil in gm;

m3 = mass of bottle, soil and water in gm; and

m4 = mass of bottle when full of water only in gm.



The specific gravity is calculated at temperature 27oC 0.2

oC. If the room temperature is differ

from 27oC, following correction is necessary:

(II)

Where, correctedspecificgravityat27oC,and. (III)

PROCEDURE

1. Five density bottles are washed in distilled water and dry it in thermostatically controlled

drying oven, capable of maintaining a temperature of 105oC to 110

oC. Cool it in

desiccators.

2. Weigh the bottle with stopper to nearest 0.001 gm (m1).

3. Take oven dried Soil sample of 50 gm passing through 4.75 mm and Transfer 5 gm of the

oven dried soil sample in the density bottle. Weigh the bottle with stopper and soil

sample (m2).

4. Add sufficient air free distilled water so that soil is just covered. Place the bottle

containing water and soil without stopper in vacuum desiccators which is evacuated

gradually. The bottle is kept 1 hour in the desiccator until no further loss of air is

apparent.

5. Release the vacuum and remove the lid of the desiccator. Stir the soil in the bottle

carefully with a spatula. Before removing the spatula from the bottle, the particles of soil

adhering to it should be washed off with a few drops of air free water. Replace the lid of

the desiccator and again apply vacuum. Repeat the procedure until no more air is evolved

from the specimen. (if desiccator is not available, the entrapped air can be removed by heating density bottle on water bath or sand bath).

6. Remove the bottle from desiccator and fill again with air free distilled water upto neck of

bottle. The stopper is placed in each bottle and kept in constant temperature bath till it

maintain constant temperature but if temperature of room is constant it is not necessary.



If volume of water is decreased, remove stopper and filled with water upto neck and

placed again in constant temperature bath until attained constant temperature.

7. Take out the bottle from water bath, wiped dry and weighed to the nearest 0.001gm (m3).

8. Clean the bottle and filled with air free distilled water upto neck, keep in water bath. If

any change in volume, fill water and again keep in water bath until constant temperature

is reached.

9. Weigh the bottle filled with water and closed with stopper (m4).

OBSERVATIONS AND CALCULATIONS:

Specific Gravity of Soil Solid (Gs) Name of Test: Specific Gravity of Fine Grained Soil Date of Testing: 14-Aug.-2012

Location of Test: Soil Mechanics Lab, IISc, Bangalore, India.

Description of Soil: Red silty clay Tested By: Group 2

S.N. Observations and Calculations Determination No.

1 2 3 4 5 Observations

1 Room Temperature in 0C 23.4 23.4 23.4 23.4 23.4

2 Density Bottle No. I II III IV V

3 Mass of empty density bottle in gm (m1) 29.8 33.68 30.22 27.84 29.99

4 Mass of density bottle + Soil in gm (m2) 37.79 41.66 38.24 35.9 37.99

5 Mass of density bottle + Soil + Water in gm (m3) 85.51 89.02 86.16 82.9 85.77

6 Mass of density bottle + Water in gm (m4) 80.55 84.11 81.25 77.96 80.85

Calculations 7 m2-m1 7.99 7.98 8.02 8.06 8

8 m4-m1 50.75 50.43 51.03 50.12 50.86

9 m3-m2 47.72 47.36 47.92 47 47.78

10 Specific Gravity using Formula in Eq. (I) 2.64 2.60 2.58 2.58 2.60 11 Average Specific Gravity (23.4

oC) 2.59

12 Temperature correction factor K (using Eq. (III) 1.000925199

13 Corrected G (at 27oC), using Eq.(II) 2.59



RESULT AND DISCUSSION

The specific gravity of soil sample at 270C is 2.59. The value shows, the soil sample is organic

clay because the range of specific gravity for organic clay is 2.58 to 2.65 but in some book range

is 1.0 to 2.60. We know that smaller the particle size, higher the value of specific gravity and

vice versa. According to IS soil classification system, organic clay has high compressibility and

liquid limit greater than 50. Similarly, it has medium to high dry strength and high toughness but

dilatancy is very slow. It has very poor bearing capacity and also compaction characteristic is

very poor. The value as sub-grade, sub-base and base for road construction when not subjected to

frost action is poor to very poor and generally not suitable. It has practically impervious drainage

characteristics. The unit weight, CBR value and sub-grade modulus are 1.28-1.76 g/cm3, 5 or

less % and 0.69 to 2.77 kg/cm3 respectively. Hence it is not suitable for civil engineering

construction work, especially for road, airfields and embankment construction. This value is used

in hydrometer analysis and useful to compute soil density.




LAB REPORT

ON

DETERMININATION OF THE PERCENTAGE OF DIFFERENT GRAIN SIZES IN SOIL PASSING THROUGH 4.75 IS SIEVE AND RETAINED ON

75-MICRON IS SIEVE




16th August, 2012

1 Lab Report on Grain Size Analysis by Wet Sieving


NAME OF TEST: TO DETERMINE THE PERCENTAGE OF DIFFERENT GRAIN SIZES IN SOIL PASSING THROUGH 4.75 IS SIEVE AND RETAINED ON 75-MICRON IS SIEVE

APPARATUS REQUIRED:

a) Balance sensitive to 0.1 percent of the mass of sample to be weighted.

b) IS sieves (300mm dia.) of mesh sizes 4.75 mm, 2.36mm, 1.18mm, 600, 300, 150,

75 with lid and pan.

c) Thermostatically controlled oven to maintain temperature between 105 and 1100C.

d) Trays and Buckets

e) Brushes

f) Mechanical sieve shaker

THEORY:

The distribution of different grain sizes affects the engineering properties of soil. Grain size

analysis provides the grain size distribution, and it is required in classifying the soil. Grain size is

one of the suitable criteria of soils for road, airfield, dam and other embankment construction. It

is also used to predict soil water improvement, susceptibility to frost action and filter design of

dam. The particle size analysis is attempted to determine the relative proportion of the different

grain sizes that make up a given soil mass.

A grain size distribution curve is also used to determine the coefficient of uniformity (Cu) and

coefficient of curvature (Cc).

Co-efficient of Uniformity (Cu) = ...... (I)

Co-efficient of curvature (Cc) = .. (II)

Where,

D60 = diameter of particles corresponding to 60% fines;

D10 = diameter of particles corresponding to 10% fines, also known as effective size;

D30 = diameter of particles corresponding to 30 % fines;

PROCEDURE: 1. Take 500gm oven dried sample passing through IS sieve 4.75mm.



2. Clean the different sizes of sieve with brushes and weigh all sieves separately in balance.

3. Assemble sieve in ascending order of sizes i.e. 4.75mm, 2.36mm, 1.18mm, 600, 300,

150, 75 and pan. Carefully pour the soil sample into top sieve and place lid on top.

4. Place the sieve stack in the mechanical shaker and shake for 10 minutes.

5. Remove the stack from the shaker and carefully weigh and record the weight of each

sieve with its retained soil and also weigh the soil retained in pan.


Sieve Analysis of Fraction Passing 4.75mm IS Sieve but Retained on 75-Micron IS Sieve Name of Test: Grain Size Analysis Date of Testing: 09-Aug.-2012


Description of Soil: Red sand Tested By: Group 1

MassofSampleTakenforAnalysis=500gm.

ISSieveDesignation

MassofsoilRetainedandMassofContainer

MassofContainer

MassofSoilRetained

CumulativeMassRetained

SoilRetainedas%ofPartialSoilTaken

SoilPassingasPercentageofPartialSoilSampleTakenforAnalysis

mm gm gm gm gm % %I II III IV=IIIII V VI=V/500.22% VII=100VI

4.75 506.62 506.62 0 0 0.000 100.0002.36 439.46 427 12.46 12.46 2.492 97.5081.18 423.29 334.62 88.67 101.13 20.217 79.7830.6 617.3 428.11 189.19 290.32 58.038 41.9620.3 523.11 376.97 146.14 436.46 87.254 12.7460.15 397.4 344.32 53.08 489.54 97.865 2.1350.075 364.37 356.8 7.57 497.11 99.378 0.622Pan 366.59 363.48 3.11 500.22 _ _

From graph,

D60 = 0.8, D30 = 0.47 and D10 = 0.28;

From Eq. (I), Cu = 2.85 < 4

From Eq. (II), Cc = 0.986 1



RESULT AND DISCUSSION:

From grain size distribution curve it is found that, soil consists of 2% silt, 23% fine sand and

75% coarse grained sand. The coefficient of uniformity is less than 4 and coefficient of curvature

is near to 1. Hence, soil is classified as uniformly graded sand containing particle of same size

with slightly silt.




LAB REPORT-3

ON

GRAIN SIZE ANALYSIS OF SOIL BY WET SIEVE METHOD




21th August, 2012



NAME OF TEST: TO DETERMINE THE PERCENTAGE OF DIFFERENT GRAIN SIZES BY WET SIEVE METHOD FOR SOIL PASSING THROUGH 4.75 IS SIEVE AND RETAINED ON 75-MICRON IS SIEVE.

APPARATUS REQUIRED: a) Balance: - sensitive to 0.1 percent of the mass of sample to be weighted. b) Sieves: IS sieves conforming to IS: 460 (part I)-1978: 4.75mm, 2mm, 1.18mm, 600,

425, 300, 150, 75 and pan. c) Oven: - thermostatically controlled maintain the temperature between 105 and 1100c with

interior of non-corroding material. d) 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 trays are in the range of 45 to 90 cm2 and 8 to 15 cm deep)

e) Brushes: - sieve brushes and wire brushes or a similar stiff brush. f) Mechanical sieve shaker (optional) g) Riffler

REAGANTS REQUIRED: Sodium hexametaphosphate (NaPO3), chemically pure or a mixture of sodium hydroxide and sodium carbonate or any other dispersing agent which has been found suitable.

THEORY: The distribution of different grain sizes affects the engineering properties of soil. Grain size analysis provides the grain size distribution, and it is required in classifying the soil. Grain size is one of the suitable criteria of soils for road, airfield, dam and other embankment construction. It is also used to predict soil water improvement, susceptibility to frost action and filter design of dam. The particle size analysis is attempted to determine the relative proportion of the different grain sizes that make up a given soil mass.

A grain size distribution curve is also used to determine the coefficient of uniformity (Cu) and coefficient of curvature (Cc).

Co-efficient of Uniformity (Cu) = ...... (I)



Co-efficient of curvature (Cc) = .. (II)

Where,

D60 = diameter of particles corresponding to 60% fines; D10 = diameter of particles corresponding to 10% fines, also known as effective size; D30 = diameter of particles corresponding to 30 % fines;

PROCEDURE: 1) The soil oven dried and passing through 4.75mm is taken. 2) The riffled and weighed fraction shall be spread out in large tray or bucket and cover with

water.

3) Two grams of sodium hexametaphosphate (NaPo3) 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 amount of dispersing agent may be varied depending on the type of soil. A dispersing agent may not be required in the case of all soils; in such cases the wet sieving may be carried out without the addition of dispersing agent.) The soil soaked specimen should be washed thoroughly stirred and left for soaking.

4) The soil soaked is washed through 75 IS sieve until 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.

5) The dried soil sample is sieved through nest of sieves 4.75mm, 2mm, 1.18mm, 600, 425, 300, 150, 75 and pan in mechanical sieve shaker.

6) The fraction retained on each sieve should be weighed separately and the mass recorded.


Sieve Analysis of Fraction Passing 4.75mm IS Sieve but Retained on 75-Micron IS Sieve Name of Test: Grain Size Analysis by wet sieving Date of Testing: 16-Aug.-2012 Location of Test: Soil Mechanics Lab, IISc, Bangalore, India. Description of Soil: Red sand Tested By: Group 2 MassofPartialSampleTakenforAnalysis=263.22gm.



ISSieveDesignation

MassofsoilRetainedonContainer

CumulativeMassRetained

SoilRetainedas%ofPartialSoilTaken

SoilPassingasPercentageofPartialSoilSampleTakenforAnalysis

mm gm gm % %I II V VI VII

4.75 5.98 5.98 2.272 97.7282.36 11.95 17.93 6.812 93.1882 4.44 22.37 8.499 91.501

1.18 24.17 46.54 17.681 82.3190.6 52.49 99.03 37.623 62.377

0.425 22.05 121.08 46.000 54.0000.3 31.4 152.48 57.929 42.0710.15 66.23 218.71 83.090 16.9100.075 44.05 262.76 99.825 0.175Pan 0.95 263.71 100.186 _



From graph,

D60 = 0.55, D30 = 0.21 and D10 = 0.12; From Eq. (I), Cu = 4.583 > 4 From Eq. (II), Cc = 0.668


From grain size distribution curve it is found that, soil consists of 52% fine sand, 40% medium 8 % coarse grained sand. The coefficient of uniformity is more than 4 and coefficient of curvature is 0.668. Hence, soil is classified as well graded soil.




LAB REPORT

ON

DETERMININATION OF THE MINIMUM DENSITY (LOOSEST STATE) AND MAXIMUM DENSITY (DENSEST STATE) OF

COHESIONLESS SOIL




16th August, 2012

1 Lab Report on Relative Density


NAME OF EXPERIMENT: TO DETERMINE THE MINIMUM DENSITY (LOOSEST STATE) AND MAXIMUM DENSITY (DENSEST STATE) OF COHESIONLESS SOIL.

NAME OF APPARATUS USED:

i. Vibratory table: steel table with vibrating deck about 75 x 75 cm, capacity to vibrated

over 45 kg, having 3600 vibrations per minute and amplitude of 0.05-0.25mm, should be

suitable for use with 415-V three phase supply.

ii. Moulds with guide sleeves: capacity of 3000 and 15000 cm3.

iii. Surcharge base plates with handle: 10mm thick base plates.

iv. Surcharge masses: 24.7 0.2 kg for 3000 m3 and 86.0 0.5 kg for 15000 cm

3.

v. Dial gauge holder

vi. Dial gauge

vii. Calibration bar

viii. Pouring devices

ix. Mixing pans

x. Weighing scale

xi. Hoist

xii. Metal hand scoop

xiii. Bristle brush

xiv. Timing device

xv. Metal straight edge

xvi. Micrometer

THEORY:

Density index or relative density is the ratio of the difference between the void ratio of a

cohesionless soil in the loosest state and any given void ratio to the difference between its void

ratios in the loosest and the densest state. The concept of density index (relative density) gives a

practically useful measure of compactness of soil. The compactive characteristics of cohesionless

soils and the related properties of such soils are dependent on factors like grain size distribution

and shape of individual particles. Density index is also affected by these factors and serves as a

parameter to correlate properties of soils. Various soil properties like, penetration resistance,

compressibility, compaction friction angle, permeability and California bearing ratio are found to

have simple relations with density index. Hence, for such purpose it is necessary to find out

maximum and minimum density of soil.

The minimum and maximum density can be calculated as:

Fig. General arrangement of apparatus. (Source: IS:2720(part 14)-1983, page 173)



Minimum density (min.) =Wsm/Vc .... (1) Where,

Wsm = mass of dry soil in minimum density test in gm; and

Vc = calibrated volume of mould in cm3.

Maximum density (max.) = Ws/Vs.. (2) Where,

Ws = mass of dry soil in the maximum density test in gm.

Vs = volume of soil in maximum density test in cm3.

= Vc (Di Df) A;

Di = initial dial gauge reading in cm;

Df = final dial gauge reading on the surcharge base plate after completion of vibration period in

cm; and

A = cross-sectional area of mould in cm2

Density index (Relative Density): it expressed as percentage should be calculated as;

... (3)

Or in terms of void ratio,

... (4)

Where,

emax =void ratio of the soil at loosest state,

e = void ratio of the soil in the field and

emin = void ratio of the soil in its densest state obtainable in laboratory

d = the dry density of the soil in the field.



PROCEDURE

There are two method of obtaining minimum and maximum density i.e. using vibratory table and

vibratory hammer. Also from vibratory table, maximum density can be achieved by dry and wet

method. Here, in laboratory, we used vibratory table and done by dry method.

Followings are the procedures:

1) Calibration: i. Determination of volume by direct measurement: volume is calculated by

measuring inside diameter and height of the mould to 0.025mm.

ii. Determination of volume by filling with water: volume is calculated by filling the

water in the mould and weights it. Then mass of water in the mould is multiplied

by volume of water per gram at measured temperature.

iii. Determination of initial dial gauge reading: six dial gauge readings should be

obtained after filling the soil sample in the mould and keeping surcharge plate

over the soil sample , three in left side and three in right side and these sixed

readings averaged.

2) Soil sample: - oven dried representative soil sample is taken but the mass of sample depends upon maximum size particle in the soil.

3) Procedure for determination of minimum density: i. Measure the weight and volume of mould.

ii. Pour the sample in the mould by spout keeping 25 mm high free fall in spiral

motion from outside towards the centre to form uniform thickness without

segregation.

iii. The mould should be filled approximately 25 mm above the top and leveled with

top by one continuous path with steel straightedge.

iv. Take the weight of mould and sample.

v. Take six initial dial gauge reading including with surcharge plate and average it

for initial dial gauge reading.

4) Procedure for determination of maximum density: i. The mould is fixed in the vibrating plate. Keep the guide sleeve at the top of the

mould and clamp it with mould.



ii. Apply Surcharge weight to the base plate over sample, inserting it in guide

sleeves.

iii. Vibrate sample for 8 minutes. Remove the surcharge weight and guide sleeves.

iv. Obtained again the six dial gauge reading and average it for final dial gauge

reading.

v. Measure the weight of sample and mould.


DETERMINATION OF LOOSEST AND DENSEST STATE OF COHESIONLESS SOIL Name of Test: Density Analysis Date of Testing: 21-Aug.-

2012


Description of Soil: Red sand Tested By: Group 2

Observations Weight of Empty Mould 3.976 kg

Weight of Empty Mould +

Soil Sample 8.442 kg

Diameter of Mould 150 mm

Height of Mould 170 mm

Least count of dial gauge 0.01 mm

Thickness of Base Plate 115 cm

Dial Gauge Reading

Initial Dial

Gauge

Reading

Multiplied

by L.C.

mm

Average

Value

(Di) cm

Final

Dial

Gauge

Reading

Multiplied

by L.C.,

mm

Average

Value

(Df), cm

i 1293 12.93

1.228

3156 31.56

3.120ii 1134 11.34 3039 30.39iii 1139 11.39 3142 31.42iv 1352 13.52 3100 31v 1235 12.35 3147 31.47vi 1213 12.13 3137 31.37

Di - Df 1.893 cmVolume of mould (Vc) 3004.15 cm

3Weight of Sample(Wsm) 4466 gmX-Section area of mould

(A) 176.63 cm2

Minimum Density (min) 1.487 gm/cm3Maximum Density (max) 1.673 gm/cm3




The minimum unit weight and maximum unit weight are 14.78 KN/m3 and 16.73 KN/m

3

respectively.

The field density of soil sample should be lie in between minimum and maximum density. The

field density can be determined from sand replacement method. Then only we can determine

relative density of soil. But field density test of soil is beyond the scope for now.




LAB REPORT

ON

THE PERCENTAGE OF DIFFERENT GRAIN SIZES IN SOIL PASSING THROUGH 75-MICRON IS SIEVE BY HYDROMETER ANALYSIS.




16th August, 2012

1 Lab Report on Grain Size Analysis by Hydrometer


NAME OF TEST: TO DETERMINE THE PERCENTAGE OF DIFFERENT GRAIN SIZES IN SOIL PASSING THROUGH 75-MICRON IS SIEVE BY HYDROMETER ANALYSIS.

APPARATUS AND MATERIAL REQUIRED: 1. Hydrometer (should be no abrupt change in dimension, graduated on the basis of liquid

having a surface tension of 55 dynes/cm, the scale is at interval of 0.0005, the basis of

scale shall be density at 270c, and the permissible error should be 0.0005).

2. Glass measuring cylinder (3 nos, 1000ml capacity of 7 cm dia. and 33cm high)

3. Thermometer (range 0.50c)

4. Stirring apparatus (mechanical device, speed 8000 to 10,000 rev/min)

5. Sieves (2mm, 425 , 75, IS sieves and pan)

6. Weight balance (accuracy of 0.01 g)

7. Oven (thermostatically controlled to maintain temperature of 105 to 1100c with non

corroding material inside)

8. Stop watch

9. Desicator

10. Centimeter scale

11. Porcelain evaporating dishes (4.15 cm dia.)

12. Wide mouth conical flask or conical beaker

13. Funnel about 10 cm dia.

14. Measuring cylinder of 100 ml capacity

15. Glass rod

16. 7 gm Sodium carbonate (Na2CO3) and 33 gm sodium

hexametaphosphate (NaPHO3).

Figure 1: Hydrometer (Source: IS 2720 (part 4)-1985, Page 82)

THEORY:

Hydrometer analysis is a widely used method to determine the percentage of soil particle passing

through 75 micron IS sieve. The data are plotted in semi-log graph combined with the data from

mechanical sieve analysis (Wet sieve) to get complete grain size distribution curve.

The hydrometer analysis is based on stokess law which gives the relation among the velocity of

fall of spheres in a fluid, the diameter of a sphere, the specific weight of the sphere and of the

fluid, and the fluid viscosity. In equation from the relationship:



..(1)Where,

= velocity of fall of the spheres Gs = specific gravity of the spheres

Gf = specific gravity of fluid varies with temperature

= absolute or dynamic viscosity of fluid (g/cm.s) D = diameter of sphere, cm (from equation 4)

PROCEDURE: I. Calibration of hydrometer

a. Volume of hydrometer bulb (Vh): keep 800ml water in 1000ml cylinder, take

reading and immersed hydrometer at water level, take another reading of rises

water level.

Hence, volume of hydrometer is the difference between water level after

immersion of hydrometer and before immersion of hydrometer. The rise of water

level due to stem weight is neglected.

II. Calibration a. Cross-sectional area of 1000ml cylinder: mark the two different water levels in

the cylinder and measure the distance between them. Hence, the cross-sectional

area of the cylinder is the ration of volume of water included between two

graduation and measured distance in cm between graduation.

b. The distance from the lowest calibration mark on the stem of the hydrometer to

each of the other major calibration marks (Rh) is measured and recorded.

c. Record the distance from the neck of the bulb to the nearest calibration mark.

d. The height (H) is equal to the summation of (b) and (c).

e. Measure the distance from the neck to the bottom of the bulb.

f. Calculated the effective depth (HR) corresponding to the major calibration marks

(Rh)

........................................................................................ (2)

Where,

HR = effective depth

H1 = length between neck to graduation Rh in cm



h = length between neck to the bottom

Vh= volume of hydrometer bulb

A = X-sectional area of cylinder

III. Meniscus correction (Cm) : Insert the hydrometer in the 1000ml cylinder containing 700 ml

distilled water.

Take the reading of upper and lower water level in hydrometer reading.

The difference between two readings is meniscus correction (Cm) and is constant for given hydrometer.

IV. Pre-treatment of soil Pre-treatment of soil is necessary when soil containing more than one percent of soluble

salts, then the soil should be washed with water before use.

If the soil is lateritic soil will be attacked by the acid but unless they contain calcium, need not be given the acid treatment. Ehen the soil containing insoluble calcium salts,

acid treatment is necessary.

V. Dispersion of soil Take 50 gm of soil sample passing through 75 IS sieve. (for clay 50gm and 100gm

sand)

Mixed 33 gm sodium hexametaphosphate and 7 gm sodium carbonate and mixed with 100 ml water.

Keep the soil suspension in the mechanical stirring device for 15 minutes. Keep the sample in 1000ml cylindrical and fill the soil sample with distilled water upto

1000ml.

Take another cylinder with distilled water. VI. Sedimentation of soil Soaked the cylinder vigorously then keep hydrometer in the cylinder, stop watch started. Take reading after min., 1 min, 2 min, and 4 min and temperature also.

Figure 2: Calibration of Hydrometer (Source: IS 2720 (part 4)-1985, Page 86)



Removed the hydrometer slowly, rinsed in the distilled water and keep the hydrometer in distilled water at same temperature as soil suspension.

Reinserted the hydrometer in the suspension and take readings after periods of 8, 15, 30 min, 1, 2, and 4 hrs after shaking. The hydrometer shall be removed rinsed and placed in

distilled water after each reading. This is due to avoid distributing the suspension

unnecessarily. Take 10 second for each operation.

For temperature correction, take the temperature of suspension at every reading near to 0.5

0c. For that, hydrometer temperature is taken at pure distilled water at same

temperature. The difference between the reading in hydrometer and that of the distilled

water is correction for temperature.

Measure the correction for dispersion agent, take reading of hydrometer by inserting in 1000ml cylinder containing distilled water and same proportion of dispersing agent. It is

also called zero correction (x).

CALCULATIONS AND OBSERVATIONS

Calculations:

a) Loss in mass in pre-treatment

. (3)

Where,

P = loss in mass in percentage

Wb = mass of soil after pre-treatment

W = air dry moisture content of soil

Wa = mass of air dry soil used

b) Sedimentation Diameter of particles

. (4)

Where,

D = diameter of particle in suspension in mm.



= co-efficient of viscosity of water at temperature of suspension at the time of

taking hydrometer reading in poises.

G = specific gravity of soil fraction used in sedimentation analysis.

G1 = specific gravity of water

HR = effective depth corresponding to Rh.

t = time elapsed between beginning of sedimentation and reading taken.

Hydrometer reading corrected for meniscus (Rh) shall be calculated as ..... (5)

Where,

Rh = hydrometer reading corrected for meniscus

Rh = hydrometer reading at upper rim of meniscus

Cm = meniscus correction

c) % finer than D

... (6)

Where,

Gs = specific gravity of soil particles;

Wb = weight of soil after pre-treatment

Rh = hydrometer reading corrected for meniscus

Mt = temperature correction

X = dispersion agent correction

Calculate the values of W for each values of D and expressed as percentage of particles finer than the corresponding value of D.



DETERMINATION OF PARTICLE SIZE DISTRIBUTION BY HYDROMETER METHOD Name of Test: Hydrometer Analysis Date of Testing: 29-Aug.-2012


Description of Soil: Red clay Tested By: Group 2

Meniscus Correction (Cm) = 0.0005 h, cm = 15.7 Specific Gravity of Soil(G) = 2.59Temperature correction (Mt) = 0.0105 Vh, ml = 70 Specific Gravity of water(G1) = 1

Dispersing Agent Correction (x) =0.0035 A, cm2 = 38.465 Total sample (wet + hydrometer) = 500 gm

Total sample retained on 75 IS sieve= 263.22 gm

Date

/Time Temp,0C

Elapsed

Time

(t),

min.

Hydrometer

Reading,

R,h

Corrected

Hydrometer

Reading,

Rh=R,h+Cm

Effective

depth (HR)

Coefficient

of viscocity

of water ()

Diameter

of

particle, D

(mm)

Rh+Mt-

x

Percentage of

Particles

Finer Than D,

W, %

Percentage

finer with

respect to

total soil

mass (Wt),%

1 2 3 4 5 6 7 8 9 10 118/29,

10:10AM 26 0 1streadingnotshown 26 0.5 1.0135 1.014 14.4800 0.0096 0.0730 21 68.42 32.40 26 1 1.013 1.0135 14.6657 0.0096 0.0520 20.5 66.79 31.63 26 2 1.0125 1.013 14.8514 0.0096 0.0370 20 65.16 30.86 26 4 1.0115 1.012 15.2228 0.0096 0.0265 19 61.90 29.31 26 8 1.0112 1.0117 16.2443 0.0096 0.0193 18.7 60.92 28.85 26 15 1.0111 1.0116 16.2814 0.0096 0.0141 18.6 60.60 28.70

10:40AM 26 30 1.011 1.0115 16.3186 0.0096 0.0100 18.5 60.27 28.5411:10AM 26 60 1.009 1.0095 17.0614 0.0096 0.0072 16.5 53.75 25.4612:10PM 26.5 120 1.007 1.0075 17.8043 0.0095 0.0052 14.5 47.24 22.372:10PM 27 240 1.006 1.0065 18.1757 0.0094 0.0037 13.5 43.98 20.836:10PM 27 480 1.005 1.0055 18.5471 0.0094 0.0026 12.5 40.72 19.281:10AM 27 960 1.004 1.0045 18.9186 0.0094 0.0019 11.5 37.47 17.7410:10AM 26 1440 1.0045 1.005 18.7329 0.0096 0.0015 12 39.09 18.5110:10AM 26 2880 1.003 1.0035 19.2900 0.0096 0.0011 10.5 34.21 16.20



Combined Wet Sieve Analysis and Hydrometer Analysis

Particle size (mm)

% Finer

4.75 98.802.36 96.412 95.53

1.18 90.690.6 80.19

0.425 75.780.3 69.500.15 56.260.075 47.450.0730 32.400.0520 31.630.0370 30.860.0265 29.310.0193 28.850.0141 28.700.0100 28.540.0072 25.460.0052 22.370.0037 20.830.0026 19.280.0019 17.740.0015 18.510.0011 16.20

Temp Visc(Poise)ofwater

5 0.0151910 0.0130720 0.0100230 0.0079840 0.0065350 0.0054760 0.0046770 0.0040480 0.0035590 0.00315

100 0.00282

Rh H1 HRupto4min HRafter4min1.0300 1.6000 8.5401 9.4500

1.0290 1.9714 8.9115 9.8214

1.0280 2.3429 9.2829 10.1929

1.0270 2.7143 9.6544 10.5643

1.0260 3.0857 10.0258 10.9357

1.0250 3.4571 10.3972 11.3071

1.0240 3.8286 10.7687 11.6786

1.0230 4.2000 11.1401 12.0500

1.0220 4.5714 11.5115 12.4214

1.0210 4.9429 11.8829 12.7929

1.0200 5.3143 12.2544 13.1643

1.0190 5.6857 12.6258 13.5357

1.0180 6.0571 12.9972 13.9071

1.0170 6.4286 13.3687 14.2786

1.0160 6.8000 13.7401 14.6500

1.0150 7.1714 14.1115 15.0214

1.0140 7.5429 14.4829 15.3929

1.0130 7.9143 14.8544 15.7643

1.0120 8.2857 15.2258 16.1357

1.0110 8.6571 15.5972 16.5071

1.0100 9.0286 15.9687 16.8786

1.0090 9.4000 16.3401 17.2500

1.0080 9.7714 16.7115 17.6214

1.0070 10.1429 17.0829 17.9929

1.0060 10.5143 17.4544 18.3643

1.0050 10.8857 17.8258 18.7357

1.0040 11.2571 18.1972 19.1071

1.0030 11.6286 18.5687 19.4786

1.0020 12.0000 18.9401 19.8500

1.0010 12.3714 19.3115 20.2214

1.0000 12.7429 19.6829 20.5929

0.9990 13.1143 20.0544 20.9643

0.9980 13.4857 20.4258 21.3357

0.9970 13.8571 20.7972 21.7071

0.9960 14.2286 21.1687 22.0786

0.9950 14.6000 21.5401 22.4500



Figure1: Graph Showing Temperature vs Visocity of water

Figure2: Graph Showing Between Actual Hydrometer Reading and Effective Depth



Figure3: Graph Showing Combined curve of wet sieve analysis and Hydrometer Analyais From graph showing in figure 3,

From graph,

D60 = 0.19, D30 = 0.02 and D10 = 0


From Combined grain size distribution curve it is found that, soil consists of 18% Clay, 16% silt

and 65% sand. Hence, soil is classified as uniformly graded sand containing particle of same size

with slightly clay and silt.

INTERFERENCES:

In the figure 3, it is shown that at particle size 0.075 mm, the graph suddenly increases, because

this zone is transition zone between coarse particle and finer particle of soil. There is no particle

lesser than 10 percent finer so, we cannot calculate the coefficient of uniformity and coefficient

of curvature of soil. The disturbance happened during immersion and removal of hydrometer

during test is neglected.




LAB REPORT

ON

DETERMINATION OF THE LIQUID LIMIT (BY MECHANICAL METHOD AND CONE PENETRATION METHOD) AND PLASTIC LIMIT

OF SOILS




4th September, 2012



NAME OF TEST: TO DETERMINE THE LIQUID LIMIT (BY MECHANICAL METHOD AND CONE PENETRATION METHOD) AND PLASTIC LIMIT OF SOILS.

EQUIPMENT: i. Mechanical liquid limit device (Casagrandes liquid limit device)

ii. Grooving tools

iii. Porcelain evaporating dish iv. Flat glass plate

v. Spatula (for mixing soil and water on the porcelain evaporating dish) vi. Palette knives (for mixing soil and water on the flat glass plate)

vii. Balance (sensitive to 0.01g) viii. Oven (thermostatically controlled with interior of non-corroding material to maintain the

temperature between 1050C to 1100C) ix. Wash bottle or beaker (containing distilled water) x. Containers (air tight and non corrodible for determination of moisture content)

xi. Rod (3mm in diameter and about 10cm long for plastic limit)

THEORY:

The swedish soil scientist Albert Atterberg (1911) originally defined limit of consistency to classify fine-grained soil. This limit is based on water content of soil. If the water content of suspension soil is gradually reduced, the soil water mixture undergoes changes from a liquid state through a plastic state and finally into solid state. Transitions of soil from one state to another state according to increase and decrease in water content are termed as Atterberg Limits. So this test is also called Atterberg limit tests.

The liquid limit is the water content at which soil changes from liquid state to plastic state. At this stage all soil behaves practically like a liquid and posses certain small shear strength. It flow close the groove in just 25 blows in Casagrandes liquid limit device. As it is difficult to get exactly 25 blows in the test 3 to 4 tests are conducted, and the number of blows (N) required in ach test determined. A semi-log plot is drawn between logN and the water content (W). The liquid limit is the water content corresponding to N=25.



Also the liquid limit can be determined by cone penetration method. The main principle of this method is to observe depths of penetrations of soils at various initial moisture contents of a metal cone of certain weight and apex angle with point barely touching the surface is allowed to drop into surface. The plot is made between water content and depth of penetration and corresponding value of water content at 20mm depth of penetration is liquid limit of given soil.

The plastic limit is the water content at which soil changes from plastic state to semi-solid state. The soil in this stage behaves like plastic. It begins crumble when rolled in to threads 3mm diameter.

Importance: The liquid and plastic limit of soils are both dependent on the amount and type of clay in a soil and form the basis for soil classification system for cohesive soil based on the plasticity tests. Besides their use for identification, plasticity tests give information concerning the cohesion properties of soil and amount of capillary water which it can hold. They are also used directly in specifications for controlling soil for use in fill. The liquid limit is sometimes used to estimate settlement in consolidations problems and both limits may be useful in predicting maximum density in compaction studies. These index properties of soil have also been related to various other properties of the soil such as follows:

Plasticity index: is the difference between its liquid limit and plastic limit. Plasticity Index (Ip) = liquid limit (WL) plastic limit (WP).... (1)

If the plastic limit is equal or greater than liquid limit, the plasticity index is reported as zero.

Flow index: the slope of line (plotted in semi-log graph between water content and number of blows) expressed as the difference in water contents at 10 drops and at 100 drops is reported as the flow index. The lower the flow index better is the shear strength.

.. (2)

Where,

W1 = moisture content in percent corresponding to N1 drops, and



W2 = moisture content in percent corresponding to N2 drops.

Toughness index: is the ratio between plasticity index (Ip) and flow index ( . The larger is the value of toughness index; the better is the shear strength at given plasticity.

..... (3)

Liquidity index (IL):

... (4)

Where,

Wo = natural moisture content of the soil

Wp = plastic limit of the soil, and Ip = plasticity index of the soil. Consistency index (Ic):

... (5)

Where,

WL = liquid limit of the soil Wo = natural moisture content of the soil, and Ip = plasticity index of the soil

PROCEDURE:

Test procedure for the determination of liquid limit (Mechanical method) I. Take 120 gm of soil sample passing through IS sieve 425 micron, mixed the sample

thoroughly with distilled water in glass plate and left for 24 hrs for uniform distribution of moisture. The paste should be such that requires 30 to 35 drops of the cup to cause the required closure of the standard groove. (Note: the soil having low texture i.e. low clay content can immediately used after mixing of distilled water).

II. Clean, dry and check the cup about free fall and adjust the liquid limit device with base falls through exactly one centimeter for one revolution of the handle.



III. Remixed the soil before using for test and placed it in cup which is rested on base. Thickness of sample in cup should be one centimeter at the point of maximum thickness shown in Fig. 1 and trim the excess soil sample.

IV. Cut the soil pat by grooving tool type A. After the soil pat has been cut by proper grooving tool, the handle is rotated at the rate of about 2 revolutions per second and the nos. of blows counted till the two parts of the soil sample come into contact for about 12 mm length.

V. Take about a little amount of soil sample from near the closed groove and find the moisture content by oven drying method.

VI. The soil of the cup is transferred to the dish containing the soil paste and mixed thoroughly after adding a little more water (in no case dry soil sample is added ). Repeat the test.

VII. By altering the water content of the soil and repeating the foregoing operations, obtain at least 4 readings in the range of 15 - 35 blows.

Test procedure for the determination of liquid limit (Cone Penetration Method) I. Prepare the sample as in mechanical method.

II. Transferred the wet soil paste into the cylindrical cup of cone penetrometer apparatus at three layers that no air is entrapped into the soil sample.

III. Level the top of surface of the soil sample and placed the cone in cylindrical cup such that cone just touches the surface of soil sample at top.

IV. Adjust the dial gauge at zero or take the reading at any graduated mark. V. Released the cone to penetrate the soil sample at its own weight of 800.5 g and after 5

second noted the depth of penetration which should be lies between 14 to 28 mm. VI. Take the soil sample from the mid of the cylindrical cup to determine the moisture

content.

VII. Repeat the test for at least four sets of value of penetration.

Test procedure for the determination of plastic limit I. Mix 20 g soil passes through 425 micron IS sieve with distilled water but in case of

clayey soil, the plastic soil masses should be left for 24 hrs to ensure the uniform distribution of water.



II. Take about 8 g of the soil and roll it with fingers on a glass plate. The rate of rolling shall be between 80 to 90 strokes per minutes to form a 3 mm diameter.

III. If the diameter of the threads becomes less than 3 mm without cracks, it shows that water content is more than its plastic limit. Kneed the soil to reduce the water content and roll it again to thread.

IV. Repeat the process of alternate rolling and kneading until the thread crumbles. V. Collect the pieces of crumbled soil thread in a moisture content container for

determination of water content. VI. Repeat the process at least twice more with fresh samples of plastic soil each time.



OBSERVATION AND CALCULATION

DETERMINATION OF LIQUID LIMIT AND PLASTIC OF FINE GRAINED SOIL Name of Test: Atterberg's limit Date of Testing: 21-Aug.-2012 Location of Test: Soil Mechanics Lab, IISc, Bangalore, India. Description of Soil: Red sand Tested By: Group 2

LIQUID LIMIT PLASTIC LIMIT Determination Number 1 2 3 4 1 2 3 4

Number of Drops 22 25 28 29

Container Number C3 C4 C7 C8 C1 C2 C5 C6 7 P-4 P-5 8 P-1 2 4 5

Weight of Container + wet soil, g

25.29 42.05 28.51 36.36 39.43 27.52 15.78 15.94 13.62 17.39 15.03 14.25 13.05 14.18 12.09 16.38

Weight of Container + oven dry soil, g

20.82 34.38 23.18 32.03 33.92 22.11 13.27 14.64 13.34 17.05 14.39 13.65 12.35 13.5 11.58 15.56

weight of water, g 4.47 7.67 5.33 4.33 5.51 5.41 2.51 1.30 0.28 0.34 0.64 0.60 0.70 0.68 0.51 0.82

weight of container, g 8.58 13.43 8.48 20.29 18.67 7.23 6.33 11.00 11.98 15.32 11.47 11.11 9.38 10.64 9.37 12.05

weight of oven dry soil, g 12.24 20.95 14.70 11.74 15.25 14.88 6.94 3.64 1.36 1.73 2.92 2.54 2.97 2.86 2.21 3.51

Moisture content, % 36.52 36.61 36.26 36.88 36.13 36.36 36.17 35.71 20.59 19.65 21.92 23.62 23.57 23.78 23.08 23.36

Average Moisture Content, % 36.57 36.57 36.24 35.94 20.12 22.77 23.67 23.22

RESULT SUMMARY Liquid

Limit (WL) Flow Index (Ip)

Plastic Limit (Wp)

Plasticity Index (Ip)

Toughness Index (IT)

Liquidity Index (IL)

Consistency Index (IC)

1 2 3 4 5 6 7

36.38 4.31 22.45 13.93 3.23_ _



LIQUID LIMIT BY CONE PENETRATION METHOD Determination Number 1 2 3 4

Depth of Penetration, cm 23.5 19.5 18.1 17.2 Container Number C1 C2 C5 C6 C3 C4 C7 C8 Weight of Container + wet soil, g 34.51 22.38 24.21 35.60 25.32 27.81 26.35 46.22

Weight of Container + oven dry soil, g 30.22 18.29 19.48 29.09 20.83 23.94 21.69 39.44

weight of water, g 4.29 4.09 4.73 6.51 4.49 3.87 4.66 6.78 weight of container, g 18.67 7.23 6.33 11.00 8.58 13.43 8.48 20.29 weight of oven dry soil, g 11.55 11.06 13.15 18.09 12.25 10.51 13.21 19.15 Moisture content, % 37.14 36.98 35.97 35.99 36.65 36.82 35.28 35.40 Average Moisture Content, % 37.06 35.98 36.74 35.34

Figure : Graph Plot for Determination of Liquid Limit By Cone Penetration Test



Figure : Showing Type of Soil on according to IS Plasticity Chart


From liquid limit and plastic limit test by mechanical method: from graph, it is found that water content at 25 Nos of blow is 36.38%. Similarly, the plastic limit of soil is 22.45%. Flow index is 4.31. Plasticity index and toughness index are 13.93 and 3.23 respectively.

From cone penetration test: it is found that water content at 20 mm depth of penetration is 36.39 %. This is 0.01 more than that obtained from mechanical method.

The plasticity index and liquid limit obtained by mechanical methods are plotted in Indian standard plasticity chart as shown in figure, we obtained that soil falls just above the A-line and in between of 35% and 50% liquid limit line. Hence, according to IS soil classification chart, soil is classified as CI i.e. inorganic clays, gravelly clays, sandy clays, silty clays, lean clays of medium plasticity which is denoted by green colour.

But according to Unified Soil Classification (UCS) system, soil is classified as Inorganic clays (CL) of low to medium plasticity.



INTERFACES

Plasticity tests give information concerning the cohesion properties of soil and amount of capillary water which it can hold.

Identification/classification of soil. They are also used directly in specifications for controlling soil for use in fill. The liquid limit is sometimes used to estimate settlement in consolidations problems and

both limits may be useful in predicting maximum density in compaction studies.




LAB REPORT

ON

DETERMINATION OF THE SHRINKAGE LIMIT AND SHRINKAGE FACTORS OF SOIL




16th August, 2012

1 Lab Report on Shrinkage Limit Analysis


NAME OF TEST: TO DETERMINE THE SHRINKAGE LIMIT AND SHRINKAGE FACTORS OF SOIL.

APPARATUS REQUIRED: I. Oven: thermostatically controlled to maintain the temperature between 1050C and 1100C.

II. Sieve:- 425 micron IS sieve III. Weighing balance:- sensitive to 0.1g and 0.01g IV. Mercury:- clean, sufficient to fill the glass cup

V. Desiccators: with any desiccating agent other than sulphuric acid. VI. Shrinkage cups

VII. Prong Plate

VIII. Plain Plate

IX. Evaporating dish X. Spatula

XI. Measuring cylinder

THEORY: Shrinkage limit can be determined for both undisturbed and remoulded soil. It is used to find out the structure of soil. The greater shrinkage, more the disperse structure. It is possible to study the shrinkage behavior of undisturbed soil of natural or man-made deposits and get an idea of its structure. Because any soil that undergoes a volume change (Expands or contracts) with change in water content may be troublesome in like a) if used for highway or railway fills, it produces a bumpy road b) if a structural foundation is placed on it, produces uneven floors and or structural cracks seen c) if used as backfill behind a retaining wall, produces excessive thrust against the wall, which may cause it to fail.

Volume expansion and contraction depend on period of time and both on soil type and its mineral and change in water content from the reference value (water content at time of construction). Soil shrinkage (or contraction) is produced by soil suction. Suction is the phenomenon which produces a capillary rise of water in soil pores above water table. Thus it is done to obtain a quantitative indication of how much volume change can occur and the amount of moisture necessary to initiate volume changes.

Shrinkage limit can be done by mercury method, wax method and sand replacement method. But here, we have followed mercury method.



From this test we can calculate shrinkage factor such as:

a) Shrinkage index(Is) :- it is the numerical difference between the plastic and shrinkage limit (remoulded soil)

.(1)

Where,

Ip = Plasticity Index

Ws = shrinkage limit in percentage.

b) Shrinkage Limit (Ws):- the maximum water content expressed as percentage of oven dry weight at which any further reduction in water content will not cause a decrease in volume of the soil mass.

. (2)

Where,

Ws = shrinkage limit in percent;

W = moisture content of wet soil pat in percent;

V = volume of wet soil pat in ml.

Vo = volume of dry soil pat in ml, and

W0 = weight of oven-dry soil pat in gm.

When the specific gravity of soil is known, the shrinkage limit may also be calculated by the following formula:

. (3)

Where,

Ws= shrinkage limit in percent

R = shrinkage ratio and

G = specific gravity of soil fraction.



c) Shrinkage ratio (R) :- the ratio of a given volume change, expressed as a percentage of the dry volume, to the corresponding change in water content above the appropriate shrinkage limit, expressed as a percentage of the weight of the oven dried soil.

...... (4)

Where,

W0 = weight of oven-dry pat in gm and

V0 = volume of oven dry soil pat in ml.

d) Volumetric shrinkage (volumetric change) (Vs):- the decrease in volume, expressed as a percentage of the soil mass when dried, of a soil mass when the water content is reduced from a given percentage to the appropriate shrinkage limit.

(5)

Where,

W1 = given moisture content in percent

Ws = shrinkage limit and

R = shrinkage ratio

PROCEDURE:

1. Take a sample weighing about 100 gm from the thoroughly mixed portion of the material passing through 425 micron.

2. Place about 30gm of the soil sample in the evaporating dish and thoroughly mix with distilled water in an amount sufficient to fill the soil voids completely and to make the soil pasty enough to be readily worked into the shrinkage dish without entrapping of water required to obtain the desired consistency is equal to or slightly greater than the liquid limit; in the case of plastic soils, it may exceed the liquid limit by as much as percent.

3. Weight empty shrinkage dish and find the volume of shrinkage dish by pouring mercury and take weight of shrinkage dish filled with mercury.



4. Coat the inside of the shrinkage dish with a thin layer of silicone grease or Vaseline or some other heavy grease to prevent the adhesion of soil to the dish. Fill one third of the dish with soil sample and taped on the firm base so that flow allow to flow in edges. Repeat the soil filling and tapping three times and trim the dish removing excess soil and level it. Three dishes are prepared in same way.

5. Weight the dish with wet soil sample and keep in oven for 24 hrs drying.

6. Weighed again dish and dry soil immediately after removal from oven.

7. Fill the glass cup with mercury and level it plain glass plate.

8. Keep the soil pat over mercury in the cup and keep the prongs over soil pat.

9. Press the prong plate so that soil pat goes down in the cup mercury and till no mercury is displaced by soil pat. Release the prongs so that no mercury spill out during releasing from the cup. Remove the dish from cup and take the weight of dish and mercury after displaced by soil pat. From this we can get volume of dry soil pat.

10. Repeat same procedure for all three soil pat.

Figure1: Shrinkage limit Arrangement



OBSERVATION AND CALCULATION

DETERMINATION OF SHRINKAGE LIMIT OF FINE GRAINED SOIL Name of Test: Shrinkage limit Date of Testing: 03-Sep.-2012 Location of Test: Soil Mechanics Lab, IISc, Bangalore, India. Description of Soil: Red clay Tested By: Group 2 SN Description Test No. 1 Test No. 2 Tets No. 3 1 Determination No. 1 2 3 2 Shrinkage Dish No. S-1 S-2 S-3 3 Weight of Shrinkage Dish in gm 35.82 34.92 41.13 4 Weight of Shrinkage Dish + wet soil pat in gm 79.53 77.72 85.49 5 weight of shrinkage dish + dry soil pat in gm 67.80 66.18 73.56 6 weight of oven dry soil pat (W0) in gm. 31.98 31.26 32.43 7 weight of water in gm 11.73 11.54 11.93 8 Moisture content (w) of soil pat in % 36.68 36.92 36.79 9 Density of Mercury (gm/ml) 13.53 13.53 13.53 10 weight of mercury filling + weight of Glass

cup 744.53 744.76 745.08

11 weight of mercury filling shrinkage dish in gm 364.06 357.96 373.09 12 weight of Glass Cup in gm 64.22 64.22 64.22

13 weight of mercury after displaced by the dry soil pat + weight of Glass cup in gm 479.03 497.72 490.90

14 volume of wet soil pat (V) in ml 26.91 26.46 27.58 15 Weight of Mercury displaced by dry soil pat in gm 265.50 247.04 254.18

16 volume of dry soil pat (V0) in ml 19.62 18.26 18.79 17 (V-V0)/W0 x100 22.78 26.23 27.10 18 Shrinkage Limit from equation (2) 13.90 10.69 9.69 19 Average Shrinkage Limit (Ws), % 11.43 20 Shrinkage Ratio from equation (4) 1.63 1.71 1.73 21 Average Shrinkage Ratio ( R ) , gm/ml 1.69 22 volumetric Shrinkage from equation (5) 37.12 44.90 46.78 23 Average volumetric Shrinkage (Vs) 42.93 24 Plasticity Index (Ip) 13.84 25 Shrinkage Index (Is) from equation (1), % 2.41




The shrinkage limit of soil is 11.43%. The average shrinkage ration and volumetric shrinkage are 1.69 gm/ml and 42.93 respectively. Similarly the shrinkage index of soil is 2.41 %.

INTERFERENCES:

We have done three test for shrinkage limit but among three test, in test S-1, we get slightly higher value than other two, it may be due to shape of dish may not be accurate as shrinkage dish.

The volumetric shrinkage of soil is higher, it means, the volume of soil is change due to moisture content.

It will be better when test will be done by another method and comparing the result between these.




LAB REPORT

ON

DETERMINATION OF WATER CONTENT-DRY DENSITY RELATION USING

LIGHT COMPACTION


Arvind Kumar Jha Dr. P. Anbazhaghan

Ph. D. Student Department of Civil Engineering


11th September, 2012

1 Lab Report on Light Compaction Test


NAME OF TEST: DETERMINATION OF WATER CONTENT-DRY DENSITY

RELATION USING LIGHT COMPACTION.

APPARATUS REQUIRED:

1. Moulds: dimension of mould (height 127mm and inner diameter 100 mm) 2. Sample extruder 3. Weighing balances 4. Oven 5. Container: to determine water content. 6. Steel straightedge: 30 cm in a length and having one beveled edge. 7. Sieve: 4.74mm and 19 mm IS-Sieve 8. Mixing tools: tray or pan, spoon, trowel and spatula 9. Metal rammer: having mass of moving part 2.6 kg 25 gm and the length of guide pipe

shall be such that as to give a fall of 310 0.5 mm.

THEORY:

Compaction is the process of densification of soil by reducing air voids suing mechanical methods. The degree of compaction of a given soil is measured in terms of its dry density. The dry density is maximum at the optimum water content. A curve is drawn between the water content and dry density to obtain the maximum dry density and optimum water content.

The bulk density (gm/ml) of soil is calculated as follows:

(1)

Where, m1 = mass in gm of mould and base; m2 = mass in gm of mould, base and soil and Vm = volume of mould The dry density (gm/ml) can be calculated as:

(2)Where, W = water content of soil in percent. Compaction method cannot remove all the air voids and therefore, the soil never becomes fully saturated. Thus the theoretical maximum dry density is only hypothetical. The line indicating theoretical maximum dry density can be plotted along with the compaction curve. The theoretical dry density can be calculated from:



.(3)Where, G = specific gravity of soil Yw = density of waterThe purpose of laboratory testing is to determine the proper amount of mixing water to be used, when the compacting soil in the field and resulting degree of compactness which can be expected from compaction at optimum moisture content.

Figure: Layout of metal rammer and Mould According to IS

PROCEDURE: Take a representative portion of air dried soil material and of sufficient quantity such that 6 kg of material passing through 20 mm IS sieve for soils not susceptible to



crushing during compaction, or 15 kg of material passing through 19-mm IS sieve for soils susceptible to crushing during compaction.

Sieve the 15 kg sample through 19-mm IS sieve and broken down sample so that, it will sieved through 4.75-mm sieve.

Take five samples each of 2.5 kg and mixed each sample thoroughly with a suitable amount of water i.e. for sandy and gravelly soil, moisture content 4 to 6 % and for cohesive soil, moisture content less than 8 to 10 % below plastic limit are required.

Keep the soil samples in desiccators for 16 hrs such that water is soaked uniformly. Weight the empty mould with base plate which is m1 and measure the volume of the

mould (V).

Place the mould in solid place and use oil or grease in mould, collar and rammer so that soil will not attached in mould. Fill the mould with soil sample prepared in three layers and each layer is given 26 blows from 2.6 kg rammer and from height 310mm above soil. After each layer compaction, scrub surface of soil with spatula so that another layer bond together then keep another layer and give 25 blows.

Remove the collar and remove the extended soil and leveled the compacted soil by using straightedge.

Weight the mould with base plate and soil sample (m2). Then remove the soil specimen from mould and take the soil of different three layers

for determination water content (w).

Repeat the test for at least five times such that maximum dry density will occur at range of water content.




Figure: compaction characteristics curve showing zero air void line

(d)max

OMC



DETERMINATION OF MAXIMUM DRY DENSITY AND OPTIMUM WATER CONTENT

Name of Test: Light Compaction Date of Testing: 5-Sept.-2012 Location of Test: Soil Mechanics Lab, IISc, Bangalore, India. Description of Soil: Red clay Tested By: Group 2 Wt. of base plate and Mould = 4.006 kg Specific Gravity (G)= 2.59

Height of Mould (Ht)= 127 mm Diameter of Mould = 100 mm

Volume of the Mould = 0.000997 m3

S.N.

Wt. of

Mould

with base

plate +

soil

Wt of soil

in Mould

(W), Kg.

Density

of Soil

(), KN/m

3

Can

No.

Wt.

of

Can

Wt.

of wet

soil +

Can

Wt. of

Dry

soil +

Can

Wt. of

Dry

soil

(Ms),

kg

Wt. of

Water

(Mw),

Kg

water

Content

(w), %

Average

water

Content

(w), %

Dry

Density

(d), KN/m

3

Dry

Density

at zero

void,(d), KN/m

3

1 5.825 1.819 18.236 c-1 9.40 18.62 17.74 8.34 0.88 10.55

10.39 16.521 20.02 2 10.64 16.41 15.88 5.24 0.53 10.11 c-2 9.97 19.66 18.74 8.77 0.92 10.49

2 6.003 1.997 20.021 5 12.03 22.03 20.87 8.84 1.16 13.12

13.24 17.680 18.92 c-3 10.99 23.69 22.18 11.19 1.51 13.49 4 9.37 18.60 17.53 8.16 1.07 13.11

3 6.08 2.074 20.793 11 6.33 27.19 24.49 18.16 2.70 14.87

14.73 18.123 18.39 8 15.31 29.44 27.66 12.35 1.78 14.41 3 8.48 24.74 22.63 14.15 2.11 14.91

4 6.03 2.024 20.292 6 8.59 25.04 22.59 14.00 2.45 17.50

17.59 17.256 17.45 10 11.46 41.54 37.00 25.54 4.54 17.78 9 11.00 27.51 25.05 14.05 2.46 17.51

5 6.00 1.994 19.991 1 9.38 27.19 24.31 14.93 2.88 19.29

19.45 16.736 16.90 7 11.98 23.04 21.25 9.27 1.79 19.31 12 11.10 26.74 24.16 13.06 2.58 19.75




The compaction characteristic curve obtained from light compaction is shown in above figure. From figure it is observed that optimum moisture content (OMC) is 14.5% and maximum dry density (d) max is 18.9 KN/m3. But practically it is not possible to remove 100% air void in the field from this OMC. Because we can see in the graph that zero air void line doesnt touch the compaction curve, means the density obtained in laboratory is lesser than the density at zero air voids.

INFERENCE:

The optimum moisture content and dry density of soil are used to measure the field compaction by calculating relative compaction. OMC and dry density of soil also affect in shear strength, soil structure, permeability, void ratio etc. Hence, these values are necessary for different civil construction work like highway, dam, embankment etc.




LAB REPORT

ON

UNCONFINED COMPRESSIVE STRENGTH OF REMOULDED SOIL





Lab Report on Unconfined Compressive Strength Test


NAME OF TEST: TO DETERMINE UNCONFINED COMPRESSIVE STRENGTH OF REMOULDED SOIL USING CONSTANT STRAIN RATE.

APPARATUS REQUIRED: 1. Compression device: having load measured up to 0.01 kg/cm

2 and axial deformation

measured up to 0.01mm.

2. Sample ejector: to prepare sample of 38 mm dia. and 76 mm length.

3. Deformation dial gauge: with 0.01mm graduations and specific travel to permit 20

percent axial strain.

4. Scale: to measure the dimensions of sample.

5. Timer: to measure elapsed time.

6. Oven: thermostatically controlled at 1100.50C

7. Weighting balances: specimen of 100gm weighed nearest to 0.01g, and larger nearest to

0.1g.

8. Miscellaneous equipment: specimen trimming and carving tools, remolding apparatus,

water content cans etc.

THEORY:

The maximum load that can be transmitted to the sub soil by a foundation depends upon the

resistance of the underlying soil or rock to shearing deformations or compressibility. Therefore,

it is of prime importance to investigate the factors that control the shear strength of these

materials. The shearing strength is commonly investigated by means of compression tests in

which an axial load is applied to the specimen and increased until failure occurred. The use of

compression tests to investigate the shearing strength of material depends upon the fact that

failure in such tests takes place by shear on one or more inclined planes and that it is possible to

compute normal pressure and shearing stress on such a plane at the instant of failure.

Thus, the unconfined compressive strength (qu) is the load per unit area at which the cylindrical

specimen of a cohesive soil fails in compression. . (1)



Where,

P = the compressive force and

A = average cross-sectional area (corrected) of the specimen for the corresponding load P.

In geotechnical work, it is standard practice to correct the area on which the load P is acting. One

of the reasons for this area correction is to make some allowance for the way the soil is actually

being loaded in the field. The original area A0 is corrected by considering that the total volume of

the soil is unchanged as the sample shortens. The initial total soil sample volume is

..(2)But after some changes in specimen length of L, we have

.... (3)

Equating equation (2) and (3), canceling terms, and solving for the corrected area A to use in

equation (1), we obtain

.... (4)

Where,

. (5)

L = the change in the specimen length as read from the strain dial indicator and L0 = the initial length of the specimen.

With only a vertical load on the sample the major principal stress 1 is vertical and the minor (horizontal or lateral) stress is 3=0. From a Mohrs circle construction of this stress state we obtain undrained shear strength- in this case also the cohesion (Symbol Cu) - as

.. (6)

Where,

Cu = undrained shear strength or cohesion.



We can also plot a curve of stress versus strain and measure the initial slope to obtain a modulus

of elasticity Es. The loss of confining pressure nearly always gives a value of Es that is too low

for most geotechnical work.

The unconfined compression test may be either strain-controlled or stress-controlled but in stress controlled method we have to apply load increment using dead load yoke which may

produce shock during loading and may result in erratic strain response and /or the ultimate

strength falling between two stress increments. For these several reasons, strain controlled test is

mostly used in soil test rather than stress controlled method.

PROCEDURE: 1. Specimen size: the size of the specimen should be minimum diameter of 38mm and the

largest particle contained within the test specimen should be smaller than 1/8 of the

specimen diameter. The height of diameter ratio should be 2. (Because the length/diameter ratio should be large enough to avoid interference of potential 450 failure planes and small enough not to obtain a column failure.)

2. Take two soil sample, one sample contains water

content of dry side and other

contain water content of wet side.

3. Mass of the soil can be calculated

From the unit weight of soil (). 4. Compacted specimen: keep the soil

Sample in tube after oiling the tube, fix

Sampler tube in jack by nut and bolt. Press

The soil sample in tube from both side.

Tightened one side completely and other side upto 76 mm left.

After Rotating 1 and , remove the sampler tube from the jack by releasing the one side

screw and pressing other side.

5. Measure length, diameter and weight of sample and placed on the bottom of the loading

device. The upper plate should be adjusted to make contact with the specimen.

6. Adjust the dial gauge reading to zero and fix the strain rate in to 2 mm/minute, here we

use 1.2 mm/minute.

7. Record the force and deformation reading at suitable interval. Compress the sample until

failure surfaces have definitely developed or the stress-strain curve is well past its peak.

8. Keep the sample for water content and done same process of other sample.

When L/d2, no

overlap failure zones

L



OBSERVATION AND CALCULATION:

DETERMINATION OF UNCONFINED COMPRESSIVE STRENGTH Name of Test: UCS Date of Testing: 11-Sept.-2012


Description of Soil: Red clay Tested By: Group 2

Optimum Water Content = 14.70%

Least Count of Dial Gauge = 0.01mm

ForDrysidesample ForWetsidesampleWatercontent=13%(Approx.5%lessthanOMC) Watercontent=17%(Approx.5%morethanOMC)Drydensity(d)fromcompactioncurve=17.20KN/m3 Drydensity(d)fromcompactioncurve=17.20KN/m3Unitweightofsoil=19.436KN/m3 Unitweightofsoil=20.124KN/m3Volumeofsoilsampletaken=8.61*105m3(dia.38mm,length76mm)

Volumeofsoilsampletaken=8.61*105m3(dia.38mm,length76mm)

Massofsoilsample(Ms)=167.40gm(Takensoilsampleofmorethanobtained

Massofsoilsample(Ms)=173.26gm(Takensoilsampleofmorethanobtained)

Initial Length (Lo), mm = 78 Initial Length (Lo), mm = 76 Initial Area (Ao), mm2 = 1133.54 Initial Area (Ao), mm2 = 1133.54

DialGauge

ReadingsLoad(KN)

Displacement(DialgaugeReadingx0.01)mm

Strain()

CorrectedArea(A),mm

2

Compressivestress(q),KN/m

2

DialGauge

Readings

Load(KN)

Displacement(DialgaugeReadingx0.01)mm

Strain()

CorrectedArea(A),mm

2

Compressivestress(q),KN/m

2

0 0 0 0 1133.54 0.000 0 0 0 0 1133.54 0.00010 0.01 0.1 0.00128 1135.00 8.811 10 0.01 0.1 0.0013 1135.03 8.81020 0.02 0.2 0.00256 1136.45 17.599 20 0.02 0.2 0.0026 1136.53 17.59730 0.03 0.3 0.00385 1137.92 26.364 30 0.03 0.3 0.0039 1138.03 26.36140 0.05 0.4 0.00513 1139.38 43.883 40 0.04 0.4 0.0053 1139.54 35.102



50 0.07 0.5 0.00641 1140.85 61.358 60 0.05 0.6 0.0079 1142.56 43.76160 0.1 0.6 0.00769 1142.33 87.541 90 0.07 0.9 0.0118 1147.12 61.02270 0.12 0.7 0.00897 1143.80 104.913 140 0.1 1.4 0.0184 1154.81 86.59480 0.15 0.8 0.01026 1145.29 130.972 190 0.12 1.9 0.025 1162.61 103.21690 0.17 0.9 0.01154 1146.77 148.242 240 0.13 2.4 0.0316 1170.50 111.063100 0.19 1 0.01282 1148.26 165.468 290 0.14 2.9 0.0382 1178.51 118.794120 0.22 1.2 0.01538 1151.25 191.096 340 0.13 3.4 0.0447 1186.63 109.554150 0.23 1.5 0.01923 1155.77 199.002 390 0.12 3.9 0.0513 1194.85 100.431200 0.21 2 0.02564 1163.37 180.510 440 0.11 4.4 0.0579 1203.20 91.423250 0.17 2.5 0.03205 1171.07 145.166 490 0.1 4.9 0.0645 1211.66 82.531

Determination of Actual Water Content (w %) For dry side sample For Wet side sample

Wt. of sample + Container 190.83 gm Wt. of sample + Container 186.70 gm

Wt. of dry sample + Container 172.83 gm Wt. of dry sample + Container 163.49 gm

Wt. of Container 27.01 gm Wt. of Container 13.35 gm

Wt. of soil 145.82 gm Wt. of soil 150.14 gm

Wt. of water 18 gm Wt. of water 23.21 gm

Water Content, % 12.34 Water Content, % 15.46



Figure 1: Variation of Stress under Strain in UCS Test

From the graph in Figure 1,

It is found that the unconfined compressive strength (qu) of dry side sample is 205 KN/m2 and

that of the wet side sample is 119 KN/m2.

We draw a tangent in both graphs to find out modulus of elasticity (Es) of soil, it is the slope of

tangent, can be find out as follows:

For dry side soil,

For Wet side Soil,

Also, from the Mohrs Circle, we can find the undrained shear strength (Cu) of the soil.

For dry side,



For wet side soil,


From testing two sample (one containing water content of dry side and other containing water

content of wet side), it is found that the unconfined compressive strength (qu) of wet side soil

specimen (119 KN/m2) is greater than dry side soil specimen(205 KN/m

2).

But the modulus of elasticity (Es) of dry side soil (12605 KN/m2) is greater than wet side soil

(4366.81 KN/m2). But from this test we can found approximate value of modulus of elasticity

because it gives too low value than actual.

Though, there is no any lateral pressure (3 =0), so undrained shear strength (Cu) is just half of unconfined compressive strength which is also justified from Mohrs circle. The value obtained

is 125.0 KN/m2 and 59.50 KN/m

2 for dry and wet soil specimen respectively.

From this test, it is also known that the soils which have less water content than OMC, brittle

failure is occurred but soil specimen having water content more than OMC is failed by bulging.

It may be due to soil at dry side of optimum is flocculated structure. In flocculated structure soil,

if we apply load, after sometimes it collapses suddenly. But soils in wet side have dispersed

structure, so it takes more load than flocculated structure and fails by bulging. Which, we can see

from above sketch.

INFERENCE:

This test is undrained test and is based on the assumption that there is no moisture loss during the

test. This test is one of the simplest and quickest tests used for determination of shear strength of

cohesive soils. The test results provide an estimate of the relative consistency of the soil. This

unconfined compressive and undrained shear strength parameters are used to calculate bearing

capacity of soil, shear strength and settlement calculation of soil. Almost used in all geotechnical

engineering designs (e.g. design and stability analysis of foundations, retaining walls, slopes and

embankments) to obtain a rough estimate of the soil strength and viable construction techniques.

This is quick test to obtain the shear strength parameters of cohesive (fine grained) soils either in

undisturbed or remolded state. The test is not applicable to cohesion less or coarse grained soils.

The test is strain controlled and when the soil sample is loaded rapidly, the pore pressures (water



within the soil) undergo changes that do not have enough time to dissipate. Hence the test is

representative of soils in construction sites where the rate of construction is very fast and the

pore waters do not have enough time to dissipate.




LAB REPORT

ON

DETERMININATION OF CALIFORNIA BEARING RATIO

(CBR) OF SOIL





1 Lab Report on California Bearing Ratio (Cbr)


NAME OF TEST: TO DETERMINE THE CALIFORNIA BEARING RATIO (CBR) OF SOIL.

APPARATUS REQUIRED: 1. Moulds with base plate, stay and wing (175 mm Length and 150 mm Dia.) 2. Collar 3. Spacer disc 4. Metal rammer 5. Weights 6. Loading machine: capacity of 5000 Kg with movable head and base that travels at

uniform rate of 1.25 mm/min. 7. Penetration plunger: 50 mm diameter. 8. Dial gauges 9. Sieves: 4.75mm and 19 mm IS sieve. 10. Miscellaneous Apparatus: mixing bowl, straightedge, measuring scale, soaking tank,

drying oven, filter paper, dishes and calibrated measuring jar.

THEORY: This test is laboratory determination of California Bearing Ratio (CBR) which was originally published in 1965. The California bearing ratio test (usually abbreviated as CBR test) is an ad hoc penetration test developed by the California State Highway Department of USA for the evaluation of Subgrade strengths for roads and pavements. The results obtained by these tests are used in conjunction with empirical curves based on experience for the design of flexible pavements. California bearing ratio is defined as the ratio of force per unit area required to penetrate a soil mass with a circular plunger of 50 mm diameter at the rate of 1.25 mm/min to that required for corresponding penetration of a standard material with standard load (load which has been obtained from the test on crushed stone which was defined as having California bearing ratio of 100 percent). The load penetration curve is shown in figure 1. The curve shown in figure will be mainly convex upwards although the initial portion of the curve may be concave upwards due to surface irregularities. A correction shall then be applied by drawing a tangent to the upper curve at the point of contraflexure. The corrected curve shall be taken to be this tangent plus the convex portion of the original curve with the origin of strains shifted to the point where the tangent cuts the horizontal strain axis as shown in figure 1. After corrected load value shall be taken from the

soil laboratory testing report by a k jha-libre

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