summer training report on soil testing experiments

TRAINING REPORT

ON

GEOTECHNICAL ENGINEERING (SOIL TESTING)

FROM

GEOTECHNICAL ENGINEERING DIRECTORATE, RDSO

SUBMITTED FOR PARTIAL FULFILMENT OF AWARD OF DEGREE OF

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

BY

ASHISH KUMAR VERMA (1236300032)

Ambalika Institute of Management & Technology, Lucknow

AFFILIATED TO

UTTAR PRADESH TECHNICAL UNIVERSITY (UPTU)

DEPARTMENT OF CIVIL ENGINEERING

AIMT

ACKNOWLEDGEMENT

I would like to place on record my deep sense of gratitude to assistant research engineer Mr Ashutosh kumar .And N.K. Singh ,D.K. Singh senior section engineer.

I am extremely thankful to Mr. Saroj kumar for valuable suggestions and encouragement.

I also gratefully acknowledge the help and support of other faculty members of the department and in completion of the report.

Signature of Student(1236300032)

CERTIFICATE

I hereby certify that I have completed the Four weeks Training in partial fulfilment of the requirements for the award of Bachelor of Technology in Civil Engineering. I did my training in GEOTECHNICAL ENGINEERING DIRECTORATE RDSO, from 15/06/2015 to10/07/2015.The matter presented in this Report has not been submitted by me for the award of any other degree elsewhere.

Signature of Student(1236300032)

Table of Contents

Tests for Soil

Moisture Content by Oven Dry Method

Natural Moisture Content & Dry Density Test Particle Size Distribution Test

Liquid limit

Plastic limit

Shrinkage limit

Specific Gravity

Compaction

Relative Density

Permeability

Unconfined Compression Strength

Direct Shear

Triaxial

PREFACE

Simple soil tests are required for assessing quality of earthwork on Railway projects. These tests play an important role in maintaining quality of earthwork and thereby the performance of Railway formation. However, in field, while conducting stage inspections on zonal railways, it has been observed that the testing procedures vary which affects the soil testing results thereby affecting the quality of work done. Lack of knowledge and proper understanding of relevant specifications have also contributed to this situation.

In order to improve the situation, regular one week course on “QualityControl on Construction Projects” have been started at Geotechnical Engineering Directorate of RDSO, where detailed procedures for various tests are explained.

An abridged version of procedure of soil testing has been framed so that it is easy for the field supervisors involved in earthwork projects, to understand and appreciate the testing methods. In abridging, we have tried to prepare this compilation very brief. For details relevant IS code as referred for each test needs to be gone through.

WATER CONTENT BY OVEN DRY METHODAs per IS: 2720 (Part 2) - 1973]

The water content (w) of a soil sample is equal to the mass of water divided by the mass of solids.

w = [(M2 – M3) / (M3 – M1)] x100

WhereM1 = Mass of empty container, with lid.M2 = Mass of the container with wet soil & lid.M3 = Mass of the container with dry soil & lid.

APPARATUS

1. Thermostatically controlled oven maintained at a temperature of 110º ± 5ºC.2. Weighing balance, with accuracy of 0.04% of the mass of the soil taken.3. Airtight container made of non-corrodible material with lid.4. Tongs.

PREPARATION OF SAMPLE

The soil specimen should be representative of the soil mass. The quantity of the specimen taken would depend upon the Gradation and the maximum size particles.

Size of particles more than 90 percentpassing IS Sieve

Minimum quantity of the soil specimen to be taken fortest mass in g

425 μ m 252.0 mm 504.75 mm 20010 mm 30020 mm 50037.5 mm 500

PROCEDURE

1. Clean the container, dry it and weight it with lid ( M1 ).

2. Take the required quantity of the wet specimen in the container and clean it with lid. Take the mass ( M2 ).3. Place the container, with its lid removed, in the oven till its mass becomes constant ( Normally for 24 hours ).4. When the soil has dried, remove the container from the oven, using tongs.5. Find the mass ( M3 ) of the container with lid and dry soil sample.

OBSERVATION AND CALCULATION

S. No.

Observation & Calculation Unit Determination no.

1 Container No. G A2 Mass of empty container (M1) G 20.123 Mass of container + Wet soil

(M2)G 44.12

4 Mass of container + Dry soil (M3)

G 41.18

5 Mass of water MW = (M2 – M3)

G 3.14

6 Mass of solid MS = (M3 – M1) G 21.067 Water content w = (5/6) x100 % 14.91

RESULT:

Average of three determinations shall be taken. The water content of the sample = 14.91 %

PRECAUTIONS1. The wet soil specimen should be kept loosely in the container.2. Care should be taken to avoid over-heating of the soil specimen by maintaining the oven temperature at 105 -110 ºC3. Dry soil specimen should not be left uncovered before weighing.

NATURAL DRY DENSITY AND NATURAL MOISTURE CONTENT[ As per IS: 2720 (Part 2) – 1973 ]

Moisture content of soil is generally measured as a ratio of the weight of water to the weight of solids, expressed as a percentage. As soil behaviour depends on its moisture content, it is one of the basic parameters defining the soil condition.

To a control engineer, even a rapid moisture content check is extremely useful, as it gives an indication of the existing characteristics of the soil, which enables him some extent to decide on the pattern of test programme.

For quality control of compacted earth fill, measurement of in-situ density is essential. All types of earthwork construction like embankments, dams, roads, airfields and trenches need checking density for quality control.

Equipment for quick checking of density as well as accurate determination is listed here.


1. Use 75 mm and 50 mm height ring with sharp cutting edge at the bottom and removable dolly at the top.2. Orient soil stratum to loading direction similar to applied force in field.3. Insert the density ring to ejected soil sample gradually by pressing with hands.4. Carefully removed the ring with soil specimen.5. The top and bottom surface should project above and below the edges of ring for final trimming.6. Trim perfectly both sides of density ring.

PROCEDURE

1. A volume of soil is taken out by pushing a density ring of known volume into the undisturbed soil sample collected.The spoil in the density ring should be perfectly trimmed on both sides before removing the soil specimen.2. The wet soil specimen is kept in the oven for drying at the temperature of 105 -110 ºC for 24 hours. The dry weight of the specimen is taken.3. Natural dry density = Wd / V g/cc4. Natural water content = (W – Wd ) x100/ Wd %5. Average of at least two specimen test results i.e. one from top and the other from bottom of the sample should be reported.


Determination No. Unit I

Wt. of container + wet soil W1

G 202.00

Wt. of container + oven dry soil, W2

G 181.90

Wt. of container W3 G 96.26

Wt. of water ( W1 – W2 )

G 20.10

Wt. of dry soil ( W2 – W3 )

G 85.64

Volume of ring Cc 56.56

Moisture content = (W1-W2)/(W2-W3)*100

% 24.47

Dry density = ( W2 – W3 ) / V

g/cc 1.54

RESULT: dry density is 1.54 g/cc

PARTICLE SIZE DISTRIBUTION TEST

[ As per IS: 2720 (Part 4) - 1985 ]

There is large variation in types of soils from site to site. Accordingly, their behavior has also variation. To make understanding of soil in easy manner, their grouping has been done depending on size of soil particles and their water absorption capacity. Ratio of soil of different sizes are worked out from sieve analysis and hydrometer/laser particle analyzer and capacity to absorb water is worked out from liquid limit, plastic limit tests. These test are used to classify the soils. Sieving is used for gravel as well as sand size particles and sedimentation procedures are used for finer soils. For soils containing coarse and fine soil particles both, it is usual to employ both sieving and sedimentation procedures.

APPARATUS

1. Set of fine IS sieves 2 mm, 600μ, 425μ, 212μ, and 75μ2. Set of coarse sieves 20 mm, 10 mm, and 4.75 mm.3. Weighing balance, with accuracy of 0.1% of the mass of sample4. Oven5. Mechanical shaker6. Mortar, with rubber pestle7. Brushes8. Trays


1. Soil sample, as received from the field shall be dried in air or in sun. In wet weather the drying apparatus may be used in which case the temperature of the sample should not exceed 60 ºC.The clod may be broken with wooden mallet to hasten drying .the organic matter, like tree root and pieces of bark should be removed from the sample.

2. The big clods may be broken with the help of wooden mallet.Care should be taken not to break up the individual soil particles.

3. A representative soil sample of required quantity (As per Table-3 of IS: 2720-I) is taken and dried in oven at 105 -120 ºC

PROCEDURE

1. The dried sample is taken in tray and soaked with water and mixed 2 g of sodium hexametaphosphate of 2 g or sodium hydroxide of 1 g and sodium carbonate of 1 g per liter of water added as dispersive agent. The soaking of soil continued for 10 -12 hours.

2. Sample is washed through 4.75 mm IS sieve with water till substantially clean water comes out. Retained sample on 4.75 mm IS sieve shall be oven dried for 24 hours. This dried sample is sieved through 20 mm, 10 mm set of IS sieves.

3. The portion of the passing 4.75 mm IS sieve shall be oven dried for 24 hours. This oven dried material is riffled and is taken of about 200 g.

4. This sample of about 200 g is washed on 75 micron IS sieve with half litre distilled water till substantially clear water comes out.

5. The material retained on 75 μ IS sieve is collected and dried in oven at 105 - 120 ºC for 24 hours. The dried soil sample is sieved through 2 mm, 600 μ, 425 μ, 212 μ IS sieves. Soil retained on each sieve is weighed.

6. If the soil passing 75 μ is 10% or more, hydrometer method is used to analysis soil particle size.

(B) Hydrometer Analysis

1. Particles passed through 75 μ IS sieve along with water is collected and put into a 1000 ml jar for hydrometer analysis. More water if required is added to make the soil water suspension just 1000 ml. The suspension in the jar is vigorously shaken horizontally by keeping the jar in between the palms of two hands. The jar is put on the table.

2. A graduated hydrometer is carefully inserted in to the suspension with minimum disturbance.

3. At different time intervals, the density of the suspension at the c.g. of the hydrometer is noted by seeing the depth of sinking of the stem. The temperature of suspension is noted for each recording of hydrometer reading.

4. Hydrometer reading is taken at a time of 0.5, 1.0, 2.0, 4.0, 15.0, 45.0, 90.0, 180.0 minutes, 6 hrs, 24 / 48 hours.

5. By using the nomogram the diameter of the particles at different hydrometer reading is found out. (Ref. IS : 2720(Part 4) –1985, page 30).

LIQUID LIMIT TEST [ As per IS: 2720 (Part 5) - 1985 ]

The Liquid limit of fine-grained soil is the water content at which soil behaves practically like a liquid, bit has small shear strength. It flow close the groove in just 25 blows in Casagrandes liquid limit device. It is one of the Atterbergs limits. The Atterbergs limits consist of The Liquid limit, Plastic limit and Shrinkage limit. As it difficult to get exactly 25 blows in the test. 3 to 4 tests are conducted, and the number of blows (N) required in each test determined. A semi-log plot is drawn between log N and the water content (w).The Liquid limit is the water content corresponding to N=25. This index property helps in classification.

APPARATUS

1. Casagrande’s limit device2. Grooving tools of both standard and ASTM types3. Oven4. Evaporating dish5. Spatula6. 425 micron IS sieve7. Weighing balance with 0.01 g accuracy8. Wash bottle9. Air-tight and non-corrodible container for determination of moisture content.


1. Air dry the soil sample (in case drying) and break the clods. Remove the organic matter like tree roots, pieces of bark etc.2. About 100 g of the specimen passing 425 micron IS sieve is mixed thoroughly with distilled water in the evaporating dish and left for 24 hours for soaking.

PROCEDURE

1. A portion of the paste is placed in the cup of the Liquid limit device.2. Level the mix so as to have a maximum depth of 1 cm.3. Draw the grooving tool through the sample along the symmetrical axis of the cup, holding the tool perpendicular to the cup.4. For normal fine grained soil : The Casagrande tool is used which cuts a groove of width 2 mm at the bottom, 11 mm at the top and 8 mm deep.5. For sandy soil : The ASTM tool is used which cuts a groove of width 2 mm at bottom, 13.6 mm at top and 10 mm deep.

6. 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 10 mm length.

7. Take about 10 g of soil near the closed groove & find water content.

8. The soil of the cup is transferred to the dish containing the soil paste and mixed thoroughly after adding a little more water. Repeat the test.

9. By altering the water content of the soil and repeating the foregoing operations, obtain at least 5 readings in therange of 15 - 35 blows. Don’t mix dry soil to change its consistency.

10. Liquid limit is determined by plotting a ‘flow curve’ on semi-log graph between nos. of blows on logarithmic scaleand water content on arithmetical scale.

11. Generally these points lie in a straight line.

12. Water content corresponding to 25 blows is the value of Liquid limit.

RESULT : Read water content corresponding to 25 blows from the graph.

PLASTIC LIMIT [ As per IS: 2720 (Part 5) - 1985 ]

The Plastic limit of a fine-grained soil is the water content of the soil below which it ceases to be plastic. It begins to crumble when rolled in to threads of 3 mm diameter. It is the boundary between Liquid and Plastic limit. It is one of the Atterbergs limits. The Atterbergs limits consist of The Liquid limit, Plastic limit and Shrinkage limit.

APPARATUS

1. Porcelain evaporating dish about 120 mm diameter.2. Spatula3. Container to determine moisture content4. Balance with 0.01 g accuracy5. Oven6. Ground glass plate 20 x 15 cm for rolling


Take out 30 g of air dried soil from a thoroughly mixed sample of the soil passing 425 micron IS sieve, mix the soil with distilled water in a evaporating dish and leave the soil mass for naturing. This period may be up to 24 hours.

PROCEDURE

1. 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.

2. 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.

3. Repeat the process of alternate rolling and kneading until the thread crumbles.

4. Collect the pieces of crumbled soil thread in a moisture content container.

5. Repeat the process at least twice more with fresh samples of plastic soil each time.

OBSERVATION AND CALCULATIONDish No. Unit Liquid Limit Plastic Limit

Nos. of Blow

Weight of Dish + Wet Soil = W1Weight of Dish + Dry Soil = W2Weight of Dish = W3Weight of Water = (W1 – W2)Weight of Dry Soil = (W2 – W3)% Moisture = (W1 – W2) / (W2 – W3) x 100

G

G

G

G

G

G

%

A35

B28

C20

D15

17.68 17.11

18.29 19.72

14.81 14.26

15.02 16.10

6.25 6.22 6.25 7.01

2.87 2.85 3.27 3.62

8.56 8.04 8.77 9.09

33.53 35.45

37.29 39.82

- - -

21.10

19.71

18.20

19.80

18.33

16.96

11.71

9.93

9.28

1.30

1.38

1.24

8.09

8.40

7.68

16.07

16.43

16.15

RESULT

The Plastic limit shall be determined for at least three portion of the soil passing 425 micron IS sieve. The average of the result calculated to the nearest whole numbers shall be reported as the Plastic limit of soil.

SHRINKAGE LIMIT TEST[ As per IS: 2720 (Part 5) - 1985 ]

The Shrinkage limit is the water content of the soil when the water is just sufficient to fill all the pores of the soil and the soil is just saturated. The volume of soil does not decrease when the water content is reduced below the Shrinkage limit.It can be determined from the following relation – Ws = (M1 – Ms) – (V1 – V2) ץw X 100 MsWhere M1 = Initial wet mass, Ms = Dry massV1 = Initial volume, V2 = Volume after drying

APPARATUS

1. Shrinkage dish, having a flat bottom, 45 mm diameter and 15 mm height.2. Two large evaporating dishes about 120 mm diameters, with a pour out and flat bottom.3. One small mercury dish, 60 mm diameter.4. Two glass plates, one plane and one with prongs, 75 x 75 x 3 mm size.5. Glass cup, 50 mm diameter and 25 mm height.6. IS sieve 425 micron.7. Oven.8. Desiccator.9. Weighing balance, accuracy 0.01 g.10. Spatula11. Straight edge12. Mercury

PROCEDURE

1. Take a sample of mass about 100 g from a thoroughly mixed soil passing 425 micron IS sieve.2. Take about 30 g of soil sample in a large evaporating dish. Mix it with distilled water to make a creamy paste, which can be readily worked without entrapping the air bubbles.3. Take the shrinkage dish, clean it and determine its mass.4. Fill mercury in the shrinkage dish. Remove the excess mercury by pressing the plain glass plate over the top of the shrinkage dish. The plate should be flush with the top of the dish, and no air should be entrapped.

5. Transfer the mercury of the shrinkage dish to a mercury weighing dish and determine the mass of the mercury to an accuracy of 0.01 g. The volume of the shrinkage dish is equal to the mass of the mercury in grams divided by the specific gravity of the mercury.6. Coat the inside of the shrinkage dish with a thin layer of silicon grease or Vaseline. Place the soil specimen in the center of the shrinkage dish, equal to about one third volume of shrinkage dish. Tap the shrinkage dish on a firm, cushioned surface and allow the paste to flow to the edges.7. Add more soil paste, approximately equal to the first portion and tap the shrinkage dish as before, until the soil is thoroughly compacted. Add more soil and continue the tapping till the shrinkage dish is completely filled, and excess soil paste projects out about it’s edge. Strike out the top surface of the paste with the straight edge. Wipe offall soil adhering to the out side of the shrinkage dish. Determine the mass of the wet soil ( M1 ).8. Dry the soil in the shrinkage dish in an air until the colour of pat turns from dark to light. Then dry the pat in the oven at 105 to 110 ºC to constant mass.9. Cool the dry pat in a desiccator. Remove the dry pat from the desiccator after cooling and weigh the shrinkage dish with the dry pat to determine the dry mass of the soil ( Ms )10. Place a glass cup in a large evaporating dish and fill it with mercury. Remove the excess mercury by pressing theglass plate with prong firmly over the top of the cup. Wipe of any mercury adhering to the outside of the cup. Removethe glass cup full of mercury and place it in another evaporating dish, taking care not to spill any mercury from the glass cup.11. Take out the dry pat of soil from the shrinkage dish and immerse it in the glass cup full of mercury. Take care not to entrap air under the pat. Press the plate with the prongs on the top of cup firmly.12. Collect the mercury displaced by the dry pat in the evaporating dish, and transfer it to the mercury weighing dish.Determine the mass of mercury to an accuracy of 0.01 g. The volume of the dry pat (V2 ) is equal to the mass of mercury divided by the specific gravity of mercury.13. Repeat the test at least 3 times


Determination No

Unit I II III

Container No. 3 4 5Wt of container

W1 g 7.98 7.37 7.04

Wt of container + wet soil pat

W2 g 32.87 31.42 32.39

Wt of container + dry soil pat

W3 g 25.99 24.78 25.43

wet weight of soil

W2-W1 g 24.89 24.05 25.35

wt of oven dry soil pat

W3-W1 g 18.01 17.41 18.39

Wt of water W2-W3 g 6.88 6.64 6.96Moisture content of soil in (%)

% 38.20 38.14 37.85

Volume of wet soil pat

cc 12.69 12.52 12.97

Wt of mercury displaced by dry soil pat

g 113.97 113.02 114.51

Volume of dry soil pat

cc 8.38 8.31 8.42

Density of mercury

g/cc 13.6 13.6 13.6

Difference in volume

cc 4.31 4.21 4.55

Shrinkage Limit

% 14.27 13.96 13.10

RESULT

Shrinkage Limit ( average of three determinations ), WS = 13.78 %

SPECIFIC GRAVITY OF SOLIDS BY THE DENSITY BOTTLE METHOD

[ As per IS: 2720 (Part 3 / Sec-2) – 1980 ]

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 equipment mentioned below can be used to test a wide range of materials from clay to sand and gravel smaller than 10 mm. The specific gravity of solid particles is the ratio of the mass density of solids to that of water. Itis determined in the laboratory using the relation.G= ( M2 - M1 )/ (M2 –M1) – (M3 – M4 ) where M1 = mass of empty bottle M2 = mass of the bottle + dry soilM3 = mass of bottle + soil + water M4 = mass of bottle filled with water onlyThe reported result is based on water at 27 ºC

Specific gravity of water at ( Tt )G (at 27 ºC) = G ( at Tt ) x ——————————————— Specific gravity of water at (27 ºC)APPARATUS

1. 50 ml density bottle with stopper2. Oven1. Constant temperature water bath (27 ºC)2. Vacuum desiccator3. Weighing balance of accuracy 0.001 g4. Spatula

.PREPARATION OF SAMPLE

1. Disturbed soil sample is enough for this test.2. Take pulverized soil passed through 2 mm IS sieve.

Determination No. Unit IBottle no. ATemperature C 31Weight of bottle ( M1 ) G 18.57Weight of oven dry soil G 10

Weight bottle + soil ( M2 )

G 28.57

Weight of bottle + soil + water ( M3 )

G 90.88

Weight of bottle + water ( M4 )

G 84.74

Specific gravity = ( M2 – M1 )/(M2 –M1) – (M3 – M4 )

2.59

PROCEDURE

1. Clean the bottle with distilled water, dry it in oven, cool in desiccator and weigh it with stopper.2. Keep about 10-15 g of this soil in the bottle.3. Cover the soil with air free distilled water from the glass wash bottle and leave for a period of 2 to 3 hours for soaking. Add water to fill the bottle to about half.4. Entrapped air can be removed by heating the density bottle on a water bath or a sand bath.5. Keep the bottle without stopper in vacuum desiccator for about 1 to 2 hours until there is no further loss of air.6. Gently stir the soil in the density bottle by a clean glass rod, wash off carefully adhering particles from the rod with some drops of distilled water and see that no more soil particles are lost.7. Repeat the process till no more air bubbles are observed in the soil water mixture.8. Observe the temperature of the constant ( ºC ) in the bottle and record.9. Insert the stopper in the density bottle, wipe and weigh.10. Now make the bottle empty, clean thoroughly till the density bottle with distilled water at the same temperature.Insert the stopper in the bottle, wipe dry from the out side and weigh.11. Take at least two such observations for the same soil.

OBSERVATION & CALCULATION

G (at 27 ºC) = G ( at Tt ) * Specific gravity of water at ( Tt ) / Specific gravity of water at ( 27 ºC )

= 2.59 x (0.995369/ 0.996542 ) = 2.587

RESULT : specific gravity = 2.587 COMPACTION TEST [ As per IS: 2720 (Part 8) – 1983 ]

Compaction is the process of densification of soil by reducing air voids. 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.Dry density = (M / V )/ 1+ ω where M = total mass of soilV = volume of soilω = water content

APPARATUS

1. Cylindrical metal compaction mouldCapacity : 1000 cc with dia 100 mm + 0.12250 cc with dia 150 mm + 0.1Internal diameter : 100 mm + 0.1150 mm + 0.1Internal effective height of mould : 127.3 + 0.1 mmCollar : 60 mm highDetachable base plate2. Rammer Mass : for light compaction = 2.6 kgheavy compaction = 4.9 kgDia : 50 mm3. IS sieve : 19 mm & 4.75 mm4. Oven : Thermostatically controlled to maintain a temperature of 1050 to 110 0C5. Weighing Balance : sensitivity - 1 g for capacity 10 kg0.01g for capacity 200 g6. Steel straight edge of about 300 mm in length with one edge levelled.7. Gradation jar8. Large mixing pan9. Spatula


1. A representative portion of air dried soil sample ( in case of oven drying temp. < 600C) break the clods, remove the organic matter like free roots , piece of bark etc.2. Take about 6 kg - ( for soil is not susceptible to crushing during compaction)15 kg - ( for soil is susceptible to crushing during compaction)

3. Sieve above material through 19 mm IS sieve and 4.75 mm IS sieve and % passing 4.75 mm IS sieve. Do not use the soil retained on 20 mm sieve. Determine the ratio of fraction retained and that passing 4.75 mm sieve.4. If % passing retained on 4.75 mm IS sieve is greater than 20 mm IS sieve, use the larger mould of 150 mm diameter.5. Mix the soil sample retained on 4.75 mm sieve and that passing 4.75 mm sieve in the proportion determined.6. Thoroughly mix water ina) Sandy and gravely soil : 3 to 5 %b) Cohesive soil : 12 to 16 % approx.Store the soil sample in a sealed container for minimum period of 16 hours.

PROCEDURE

1. Clean and dry the mould and base plate. And apply a thin layer of grease on inside the mould.2. Weigh the mould to the nearest 1 gram. Attach the collar to the mould and place on a solid base.3. Compact the moist soil in to the mould in five layers of approximately equal mass, corrilayer being given 25 blows from 4.9 kg rammer dropped from the height of 450 mm above the soil. The blows should be distributed uniformly over the surface of each layer.4. Remove the collar and trim off the excess soil projecting above the mould by using straight edge. Take the weight of mould with compacted soil in it.5. Remove the 100 g compacted soil specimen for the water content determination.6. Add water in increment of 1 to 2 % for sandy and gravely soils and 2 to 4 % for cohesive soils.7. Above procedure will be repeated for each increment of water added. The total number of determination shall be at least four and moisture content should be such that the OMC at which MDD occurs , is within that range.

PRECAUTION

1. Ramming should be done continuously taking of height of 450 mm free fall accurately.2. The amount of soil taken for compaction should be in such a way that after compacting the last layer, the soil surfaceis not more than 5 mm above the top rim of the mould.3. Weighing should be done accurately.

RELATIVE DENSITY TEST[ As per IS: 2720 (Part 14) - 1983 ]

Relative density relates the dry density of cohesion-less soil to the maximum and minimum densities. The degree of compaction of cohesion-less soil can be stated in terms of Relative density. The test is used to determine the Relative density of cohesion less free draining soils containing upto 5 % present by weight of the soil particles passing a 75 micron IS-sieve. It is also known as Density Index.

γmax ( γd - γmin ) ( emax — e )Density Index = ——————— x 100 = ————— x 100 γd ( γmax - γmin ) ( emax – emin )

Relative Density Consistency Term0-15 Very loose15-35 Loose35-65 Medium dense65-85 Dense85-100 Very dense

APPARATUS

1. Vibratory table : a steel table with cushioned steel vibrating deck about 75 x 75 cm. The vibrator shall have frequency of 3600 vibrations per minute.2. Mould : Two cylindrical metal unit mass mould of 3000 cc and 15000 cc capacity.3. Two guide sleeves.4. Surcharges masses : as per IS: 10837-19845. Dial gauge : 50 mm travel with 0.025 mm graduation ( IS: 2092-1962)6. Calibration bar : for computing the initial dial gauge reading calculating the volume of specimen.7. Mixing pans : suitable size are 65 x 90 x 10 cm.8. Weighing scale : portable platform weighing scale, 100 kg capacity.9. Pouring devices : consisting of funnels 12 mm and 25 mm dia. and 15 cm long with cylindrical spouts.10. Metal straight edge : about 40 cm long


A representative sample of soil should be taken. The mass of soil sample to be taken depends upon the maximum size particle in the soil.

Maximum size of soil particles in mm

Mass of soil sample required in kg

Size of mould in cm3

75 45 15000

37.5 12 3000

19 12 3000

9.5 12 3000

4.75 12 3000

The soil sample should be dried in oven at temperature of 105 to 110 ºC. The soil sample should be pulverized with out breaking the individual soil particles and through required sieve.

PROCEDURE

A) DETERMINATION OF MAXIMUM DENSITY

1. The maximum density may determined by either dry or wet method.2. Assemble the guide sleeve on the top of the mould and tighten the clamp assemblies so that the inner surface of the walls of the mould and sleeve are in the line.3. Tighten the lock nuts with two set screws. Loosen the third clamp, remove the guide sleeve, weight the empty mould and record its weight.4. Fill the mould with thoroughly mixed oven dry soil by the procedure explained for minimum test. Attach the guide sleeve to the mould and place surcharge base plate on soil surface.5. Surcharge weight should then be lowered on the base plate.6. Fix the mould to the vibrator deck and loaded soil sample should be vibrated for 8 minutes.7. Remove the surcharge weight and the guide sleeve. Obtain dial gauge readings on two opposite side of the mould and record their average.8. Weigh the mould with soil and record these weight.

B) DETERMINATION OF MINIMUM DENSITY

1. Select pouring device and mould according to the maximum size of the particles.2. Weigh the mould and record its weight. Oven dry soil should be used.3. Soil containing particles smaller than 9.5 mm should placed as loosely as possible in the mould by pouring the soil through spout in a steady stream.4. The height of free fall of soil is always 25 mm. The mould should be filled approximately 25 mm above the top and leveled with top by making one continuous pass with steel straight edge.5. The mould and soil should be weighed and mass recorded.

PERMEABILITY TEST( by constant head parameter)

[ As per IS: 2720 (Part 17) - 1986 ]

The co-efficient of permeability is equal to the rate of flow of water through a unit cross sectional area undera unit hydraulic gradient. In the constant head parameter, the head causing flow through the specimen remain constant throughout the test. The coefficient of permeability ( K ) is obtained from the relation.

K =ql /Ah = QL /Ah tWhere q = discharge Q = total volume of water, t = time periodh = head causing flow, L = length of specimen, A = cross sectional area

APPARATUS

1. Permeameter mould : internal diameter =100 mm, effective height = 127.3 mm , capacity = 1000 cc.2. Detachable collar : 100 mm diameter, 60 mm high.3. Compaction equipment4. Drainage base, having porous disc.5. Drainage cap , having a porous disc with a spring attached to the top.6. Constant head water supply reservoir.7. Constant head collecting chamber.8. Stop watch9. Weighing balance10. Thermometer


A) DISTURBED SOIL SAMPLE1. Measure the internal dimensions of the mould. Weight the mould to the nearest gram.2. Apply a little grease on the inside to the mould. Clamp the mould between the base plate and the extension collarand place the assembly on a solid base.3. Take about 2.5 kg of soil sample, from a thoroughly mixed wet soil in the mould. Compact the soil at the requireddry density, using a suitable compacting device.4. After the compaction, remove the collar and base plate, trim off the surplus soil mass by means of straight edge and weigh the mould with a compacted soil.5. Saturate the stones. Place the filter paper at both the end of the soil specimen in the mould.

6. Attached this mould with the drainage base and cap having saturated porous stone.

B) UNDISTURBED SOIL SAMPLEFor testing the undisturbed soil sample, trim off the undisturbed specimen in the shape of a cylinder of about 85 mm in dia and height equal to that of mould. Put the filter paper at the both the end of the specimen and place it centrally over the bottom saturated porous stone of the drainage base fixed to the mould.Fill the annular space between mould and soil specimen with an impervious material to avoid any leakage from the sides. The impervious material may be cement slurry or a mixture of 10 % bentonite and 90 % fine sand by weight.Fix the drainage cap over the top the mould.

PROCEDURE1. Disconnect the reservoir from the bottom out let.2. Connect the constant head reservoir to the drainage cap inlet.3. Open the stop cock and allow the water to flow downward so that all the air is removed.4. Close the stop cock and allow the water to flow through the soil till a steady state is attained.5. Start the stop watch, and collect the water flowing out of the base in a measuring flask for some convenient time interval.6. Repeat this thrice, keeping the interval the same. Check that quantity of water collected is approximately the same each time.7. Measure the difference of head ( h ) in levels between the constant head reservoir and the outlet in the base.8. Repeat the test for at least two more different interval.9. Stop the flow of water and disconnect all the part of assembly. Record the temperature of the water used in the test.


Length of soil sample (L) = 12.73 cmDiameter of the soil sample (d) = 10.00 cm(It is remoulded specimen)For undrained sample, dia. = 8.5 cmArea of the soil specimen (A) = 78.54 cm²Height of reservoir above the out let of the bottom plate (h) = 150 cmTemperature of water (T) = °CObservation Unit IMass of empty mould g 5110Mass of mould + soil g 7000Hydraulic head ( h ) mm 150

Quality of flow ( Q )a) First time in period ( t )b) Second time in period ( t )c) Third time in period ( t )Average

mlmlmlmlmm3

1210

1205

1210

1215

= 1210 x 10³Permeability ( K ) =QL / A h t

Cm/sec

Mass of soil ( 2-1 ) = 1890 g.Bulk density, ρ = Mass / VolumeWater content , ω =Dry density, ρd = ρ / 1+ωVoid ratio, e = ρ ω G / ρd

RESULT

Average of three determinations shall be taken(1205+1210+1215)/3=1210 cm/sec

UNCONFINED COMPRESSIVE STRENGTH OFA COHESIVE SOI L

[ As per IS: 2720 (Part 10) – 1973 ]

The unconfined compressive strength ( qu ) is the load per unit area at which the cylindrical specimen of a cohesive soil fails in compression.

Qu=P/A

Where, P = axial load at failure,A = corrected area = A o / ( 1- ε )A o = initial area of the specimenε = axial strain = change in length / original length.The undrained shear strength (s) of the soil is equal to one half of the unconfined compressive strength,s = qu / 2

APPARATUS

1. Unconfined compression apparatus comprising hydraulic loading device with proving ring and deformation dial gauge.2. Vernier caliper3. Sample extractor4. Coning tool5. Sampling tube6. Spatula7. Split mould.

PROCEDURE1. Coat the split mould lightly with a thin layer of grease.2. Push the sample out of the sampling tube into the split mould using the sample extractor with negligible disturbance of the specimen.3. Remove the specimen from the split mould by splitting the mould into two part and use the coning tool to form cones on two ends of the specimen.4. Measure the length and diameter of the specimen and weigh it.5. Place the specimen on the bottom plate of the compression machine. Adjust the upper plate to make contact with the specimen.6. Adjust dial gauge and proving ring gauge to zero.7. The rate strain of 1.5 mm / minute is applied to soil specimen.

8. Continue the test until failure surfaces have clearly developed or until an axial strain of 20 % is reached.9. Take the sample from the failure zone of the specimen for water content determination.

DIRECT SHEAR TEST[ As per IS: 2720 (Part 13) - 1986 ]

The Direct Shear test is carried out with an apparatus consisting of a square or circular box divided into two halves. The specimen, contained in the box, is subjected to a constant normal load while an increasing horizontal force is applied to one of the sections of the shear box. This force causes a shear failure along the juncture between the box sections. The shear force and the normal load are measured directly. The rate of strain is adjusted by the speed of the horizontal force applied. The loading unit has V-Strips on which the shear box housing rests. The pre-calibrated load yoke helps counter balance the loading system. The load yoke with direct and through level system for applying normal load upto 8 Kg/cm2 capacity. Fixtures for proving ring, brackets for holding consolidation and strain dial gauges are provided.The lead screw connected to the shear box housing helps application of shear stress.Shear strength of the soil is its maximum resistance to shearing stress. The shear strength is expressed as –s = c’ + σ’ tan ø’σ’ = effective stressØ’ = effective angle

APPARATUS

1. Shear box, divided into two halves by a horizontal plane and fitted with locking and spacing screw.2. Box container to hold the shear box.3. Base plate having cross grooves on its top surface.4. Grid plates perforated (2 nos.)5. Porous stones 6 mm thick (2 nos.)6. Proving ring7. Dial gauge accuracy 0.01 mm – 2 mm8. Static compaction device, spatula.9. Loading yoke, loading frame, loading pad.


A) UNDISTURBED SAMPLE : Specimen is prepared by pushing a cutting ring of size 10 cm dia and 3 cm high , in the undisturbed soil sample. The square specimen of size 6 cm x 6 cm x 2.4 cm is then cut from circular specimen.

B) DISTURBED SAMPLE :(a) cohesive soil :- the soil may be compacted to required density and moisture content directly into the shear box after fixing the two halves of the shear box together by mean of the fixing screw.(b) cohesion less soil :- soil may be tamped in the shear box itself with base plate and grid plate or porous stone as required in place at the bottom of the box.

PROCEDURE

1. Measure the internal dimension of the shear box and average thickness of the grid plates2. Fix the upper part of the box to the lower part using the locking screw. Attach the base to the lower part .3. Place the grid plate in the shear box keeping the serration’s of the grid at right angle to the direction of shear.Place a porous stone over the grid plate.4. Weight the shear box with base plate, grid plate and porous stone.5. Place soil specimen in the box and weight the box.6. Place inside the box container and the loading pad on the box. Mount the box container on the loading pad.7. Bring the upper half of the box in contact with the proving ring. Check the contact by giving slight movement.8. Fill the container with water and mount the loading yoke on the ball placed on loading pad.9. Mount one dial gauge on the loading yoke to record the vertical displacement and another dial gauge on the containerto record the horizontal displacement.10. Place the weight on loading yoke to apply a normal stress.11. Allow the sample to consolidate under the applied normal stress. Note reading of vertical displacement dial gauge.12. Remove the locking screws. Using the spacing screws, raise the upper part slightly above the lower part such as that gap is slightly larger than the maximum particle size. Remove the spacing screws.13. Adjust all dial gauges to read zero. The proving ring also read zero.14. Apply the horizontal shear load at constant rate of strain.15. Record reading of the proving ring, the vertical displacement dial gauge.16. Continue the test, till the specimen fails or till a strain of 20 % is reached.17. At the end of the test, remove the specimen from the box.18. Repeat the test on identical specimens under the normal stress.

TRIAXIAL TEST[ As per IS: 2720 (Part 11)-1971 ]

Different types of soils show different characteristics on being subjected to loading. The test helps to determine load supporting capacity of a particular soil under fully saturated condition. This test is required for design of foundation for structure and analysis of slope stability. The test is used to determine the shear strength parameter ( C’ and Ø’ ) of soil by consolidated undrained triaxial test.


1. Remove wax sealing from field sample tube.2. Place sample cutter tube (38 mm inner dia ) on field sample tube.3. Insert sample cutter tube in the soil with the help of hydraulic jack.4. Take out the sample cutter tube from field sample tube by pushing soil with hydraulic jack.5. Transfer soil sample from sample cutter tube to split mould of proper length (76 mm).6. Take out soil specimen from split mould.

LOADING OF SAMPLE

1. Clean base of triaxial cell.2. Put porous stone over bottom pedestal and a filter paper of 38 mm dia over this porous stone.3. Place soil specimen over filter paper and put another filter paper then porous stone on the top of the soil specimen.4. Place about 8 filter paper strips vertically around soil specimen extending from top porous stone to bottom porous stone to facilitate uniform and quick saturation.5. Put rubber membrane around the soil specimen with the help of stretcher.6. Place O ring around top and bottom pedestal in the grooves.7. Place the triaxial cell and tight the nut to the base plate.

TESTING OF SPECIMEN

1. Saturate the soil sample from 24 to 48 hours, by opening drainage valve, which is connected with burettefilled with water. Water level in burette is kept little more than the top of specimen.2. After saturation triaxial cell is filled with water and all around cell pressure ( σ3 ) is applied by mercury controlled device. The pore water pressure is measured the sample is saturated until it satisfies B parameter of 1 ( not less than 90% of σ3 ).3. Four soil specimen of a sample are tested at 0.5, 1.0, 1.5, and 2.0 kg / cm2 of lateral pressure ( σ3 ).For consolidated un-drained test ( CU ), the sample is to be placed for consolidation and B parameter has to be checked. The drainage reading during consolidation in the burette is to be recorded in time interval of 1, 4, 9, 16, 25, 36.....minutes up to 24 hrs .4. On account of consolidation the length and diameter of specimen changed.5. Changed length, cross sectional area and rate of strain on consolidated specimen have to be calculated.6. Apply calculated rate of strain on consolidated specimen and note down thedeformation and corresponding load on specimen un till the failure of specimen.7. Four specimen has been tested at four confining pressure ( 0.5, 1, 1.5 and 2Kg / cm2 ) as explained above.8. Now from above reading plot Mohr’s circle and get the shear parameter C’ andØ’.Ballast (stone broken in specified range of size) transfers load from sleeper to formation soil. Ballast particles are subjected to high level of impact from sleepers and abrasion among each other due to vibrations.Test results indicate suitability or otherwise of the ballast.


1. Take ballast sample which passes 12.5 mm IS sieve and is retained on a 10 mm IS sieve.

2. The sample shall be oven dried for 4 hours at a temperature of 100-110 ºC and cooled.

3. The measure shall be filled about one third full with the prepared aggregate and tamped with 25 strokes of the tamping rod. A further similar quantity of aggregate shall be added and further tamping of 25 strokes given.

4. The measure shall finally be filled to over flowing tamped 25 times and the surplus aggregate stuck off, using the tamping rod as straight edge. The net weight of the aggregate in the measure shall be determined to the nearest gm. ( weight A ).

PROCEDURE

1. The cup shall be fixed firmly in position on the base of the machine and the whole of test sample placed in it and compacted by a single tamping of 25 strokes of the tamping rod.

2. The 13.5 -14 kg hammer shall be raised until its lower face is 380 mm above the upper surface of the aggregate in the cup and allowed to fall freely on to the aggregate. The test sample shall be subjected to total of 15 such blows each being delivered at an interval of not less than one second.

3. The crushed sample shall then be removed from the cup and the whole of it sieved on the 2.36 mm IS sieve.

4. The fraction passing through shall be weighed ( weight B ). The fraction retained on the sieve shall also be weighed ( weight C ).

5. If the total weight ( B&C ) is less than the initial weight ( weight A ) by more than one gram the result shall be discarded and a fresh test made.

6. Two tests shall be made.

CALCULATION

Aggregate impact value =B/A*100

OBSERVATION

S. No. Weight of sampletaken before impact(A)( in g )

Weight of sample passing2.36 mm IS Sieve after impact(B)( in g )

Weight of sample retained on2.36 mm IS sieve after impact( C )( in g )

Impact valueB/A*100

Remark

1 308 56 252 18

2 310 57 253 18.38

RESULT

Average value of two results =18.19%

REFERANCE

Geotechnical Engineering DirectorateResearch Designs & Standards OrganisationManak Nagar, Lucknow - 226011Uttar Pradesh (INDIA)