project on soil

8/3/2019 Project on Soil

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DEPTT.OFCIVILENGG.,BITSINDRI

[Year]

Project Report on SoilTests

Comparison of soil specimens

[ T Y P E T H E C O M P A N Y A D D R E S S ]


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ACKNOWLEDGEMENT

I take this opportunity to extend my sincere thanks to all those people whohelped and guided us, to make this endeavor of our successful one.

I am extremely grateful to Prof. J.P. SINGH of Civil Engineering Department ,

B.I.T. Sindri and avail this opportunity to express my most sincere appreciation

and deep sense of gratitude for his guidance and immense help at all stages of

work and in the presentation of the dissertation.

I also express my deep sense of gratitude to Prof. (Dr.) R.P.Sharma,

Professor & Head, Civil Engineering Department for his advice and help in

tacking innumerable difficulties in connection with this work.

I would also like to express my gratitude towards the staffs & members

of Civil Engineering Department.

The assistance and co-operation rendered by following students throughout

the project work is very much appreciated.

NAME ROLL NUMBER

Amit kumar 080509

Binit kumar 080519

Jayshree bharti 080529

Mritunjay kumar 080539

Prashant soren 080549

Rajesh Ranjan 080559Saroj rajwar 080569

Sunaram Marndi 080580

Vikash kumar 080590

Dilip kumar 070538

Kanhai Ram 090502D


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Department Of Civil Engineering

B.I.T. Sindri, Dhanbad, Jharkhand

CERTIFICATE

Thisis to certify that the project report entitled TESTS ON DIFFERENT SOIL SAMPLES

is a record of bonafide work carried out under my supervision and guidance during the

academic session 2011-2012 as a partial fulfilment of the requirement for the award of

the degree of Bachelor Of Technology(Civil Engineering) of Vinoba Bhave University ,

Hazaribag.

The project work has been successfully completed by :

NAME :

ROLL NUMBER :

Date :

Prof. J.P.SINGHDept. Of Civil Engg.

B.I.T. Sindri, Dhanbad


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Introduction to Soil Mechanics

The term "soil" can have different meanings, depending upon the field in which it is considered.

To a geologist, it is the material in the relative thin zone of the Earth's surface within which roots occur, and which are

formed as the products of past surface processes. The rest of the crust is grouped under the term "rock".

To a pedologist, it is the substance existing on the surface, which supports plant life.

To an engineer, it is a material that can be:

y built on: foundations of buildings, bridgesy built in: basements, culverts, tunnelsy built with: embankments, roads, damsy supported: retaining walls

Soil Mechanics is a discipline of Civil Engineering involving the study of soil, its behaviour and application as an

engineering material.

Soil Mechanics is the application of laws of mechanics and hydraulics to engineering problems dealing with sediments aother unconsolidated accumulations of solid particles, which are produced by the mechanical and chemical disintegratioof rocks, regardless of whether or not they contain an admixture of organic constituents.

Soil consists of a multiphase aggregation of solid particles, water, and air. This fundamental composition gives rise tounique engineering properties, and the description of its mechanical behavior requires some of the most classic principleof engineering mechanics.

Engineers are concerned with soil's mechanical properties: permeability, stiffness, and strength. These depend primarilyon the nature of the soil grains, the current stress, the water content and unit weight.


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Formation of Soils

hysical weatheringreduces the size of the parent rock material, without any change in the original composition of thearent rock. Physical or mechanical processes taking place on the earth's surface include the actions of water, frost,mperature changes, wind and ice. They cause disintegration and the products are mainly coarse soils.

he main processes involved are exfoliation, unloading, erosion, freezing, and thawing. The principal cause is climatic chexfoliation, the outer shell separates from the main rock. Heavy rain and wind cause erosion of the rock surface. Adver

mperature changes produce fragments due to different thermal coefficients of rock minerals. The effect is more for freezaw cycles.

hemical weatheringnot only breaks up the material into smaller particles but alters the nature of the original parent rocelf. The main processes responsible are hydration, oxidation, and carbonation. New compounds are formed due to theemical alterations.

ain water that comes in contact with the rock surface reacts to form hydrated oxides, carbonates and sulphates. If there lume increase, the disintegration continues. Due to leaching, water-soluble materials are washed away and rocks lose t

menting properties.

hemical weathering occurs in wet and warm conditions and consists of degradation by decomposition and/or alteration. sults of chemical weathering are generally fine soils with altered mineral grains.


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Soil formationOne of the most important scientificdiscoveries was how soil forms

spontaneously from rock. Under theinfluence of physical factors like

deformation by heat and cold, assaultby wind, rain, hail and ice, and the

enormous levering forces of waterexpanding into ice, solid rock is

shattered into smaller pieces (seepicture). But however small these

fragments, they still have the sameproperties as the parent rock.

Being formed under high pressure andtemperatures, the crystals of the

minerals in the rock are somewhat

unstable at surface pressure andtemperature. Particularly when attacked by acids that etch away the soluble components in theminerals, the crystals fall apart, albeit very slowly. It is called spontaneous weathering, but it is

accelerated considerably under the influence of vegetation and its acids (chemical weathering).During the weathering process, four components are released:

y minerals in solution (cations and anions), the basis of plant nutrition.y oxides of iron and alumina (sesquioxides Al2O3, Fe2O3).

y various forms of silica (silicon-oxide compounds).y stable wastes as very fine silt (mostly fine quartz) and coarser quartz

(sand). These have no nutritious value for plants.

Factors in soil

formation:

y parent material

y time

y climate

y atmospheric

compositiony topography

y organisms

Depending on temperature and rainfall, new minerals are formed. The oxides of ironand alumina combine with silica to form clay. In temperate regions a three-layer clay

is formed, which is weak, swells under moisture, and clogs. It is able to absorb largeamounts of water but is rather heavy on plant roots, blocking the oxygen the soil

organisms need. Because clay has a charged surface area, it is able to bind and retain

minerals and nutrients (Cation Exchange Capacity). The valuable nutrition for plants

won't leach away easily in three-layer clays.Two-layer clays are formed in hot, humid tropical regions, producing arable but easily

dried soils. These clays are not able to hold much water, or nutrients, but are still very

much better than sand.


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Soil's productivity is mainly

due to the clays in the soils.Knowing that clay particles

are very small (less than 2

microns), one can imagine

that this component is easilyeroded out of the soil. Its

small size prevents it from

sedimenting out rapidly in

water, resulting in rivers, lakes

and ocean water staying turbid

for a long time after rains haveended.

The mix of sand, silt and clay

is called a loam. In this diagram, the triangle represents all possible combinations ofthe three. Soil specialists use names for the various loams, as indicated in the diagram.

A loam can be dried and pounded in the laboratory and passed through sieves to

separate the mix by particle size. From the diagram, the official composition of 'loam'can be inferred - sand:silt:clay = 40:40:20. (Draw lines parallel to each side and read

the left-hand values.)

Sand is very workable but won't hold water, or nutrients well. Loam is poor in

nutrients, reasonably workable, but holds water well. Clay is difficult to work,

compacts easily, but holds water and nutrients well, but is reluctant to release these to

plants. As the diagram shows, the various loams derived from the three basecomponents, have varying workability, water holding capacity and cation exchange

capacity (CEC).

Not only temperature and moisture affect soil formation but also the level of the

groundwater table and the steepness and elevation. As can be seen, soil formation

depends on many factors, regional and local, resulting in an almost infinite number ofdifferent soils, each having different needs. Nutrients therefore, can vary considerably

from patch to patch, requiring careful application and observation.


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Soil profileWhereas soil is formed from therock below, it is eroded away

from the top. A cover of plant lifeslows down erosion, allowing the

soil layer to build up, but there ismore going on.

Just above the base rock, is the C-horizon, containing the recently

weathered and still weatheringsoil. It is rich in nutrients. The A-

horizon is where most plant rootsare found and all soil organisms.

Its nutrients have been used byplants or leached downward, so it

is relatively poor in nutrients, but

rich in life. By comparison, the B-horizon is the zone where new material from below and nutrients from above accumulate.Sometimes an impermeable layer or pan is formed above it (podsol), denying plants to access

this rejuvenating source of new nutrients. On the surface of the soil, often a thin layer is found,rich in leaf litter and other organic material.

horizondescription of detailed soil horizons

Oconsists mainly of organic matter from the vegetation, which accumulates underconditions of free aeration.

Aeluvial (outwash) horizon consisting mainly of mineral matter mixed with somehumified (decomposed) organic matter.

Estrongly eluviated horizons having much less organic matter and/or iron and/or claythan the horizons underneath. Usually pale coloured and high in quartz.

Billuvial (inwashed) horizon characterised by concentrations in clay, iron or organicmatter. Some lime may accumulate, but if the accumulation is excessive, the horizonis named K.

K horizon containing appreciable carbonate, usually mainly lime or calcium carbonate.

Ggleyed horizons which form under reducing (anoxic) conditions with impeded aeration,reflected in blueish, greenish or greyish colour.

Cweathered parent material lacking the properties of the solum and resembling morethe fresh parent material.

R regolith, the unconsolidated bedrock or parent material.

Soil and top soil are produced naturally at a rate of 1mm in 200-400 years, averaging

at about 1 ton/ha/y. A full soil profile develops in 2,000 - 10,000 years, a period whichis long for humans but short for the planet. World-wide, agricultural soil is lost at a

rate 10-40 times faster than its natural replacement. The USA lost 80mm since

farming began, 200 years ago. This amounts to some 18 t/ha/y. China appears to lose

40 t/ha/y. World-wide loss of agricultural land is 6 million ha per year, from a world-

wide total of 1200 million ha (0.5%/y). These are compelling reasons for improving

the way humans manage their soils.


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Soil Classification

is necessary to adopt a formal system of soil description and classification in order to describe the various materials fou ground investigation. Such a system must be meaningful and concise in an engineering context, so that engineers will ble to understand and interpret.

is important to distinguish between description and classification:

escription of soil is a statement that describes the physical nature and state of the soil. It can be a description of aample, or a soil in situ. It is arrived at by using visual examination, simple tests, observation of site conditions, geologicastory, etc.

lassification of soil is the separation of soil into classes or groups each having similar characteristics and potentiallymilar behaviour. A classification for engineering purposes should be based mainly on mechanical properties: permeabiltiffness, strength. The class to which a soil belongs can be used in its description.

he aim of a classification system is to establish a set of conditions which will allow useful comparisons to be made betw

fferent soils. The system must be simple. The relevant criteria for classifying soils are the size distribution of particles heplasticityof the soil.

TYPES OFSOIL:-

oils as they are found in different regions can be classified into two broad categories:

) Residual soils2) Transported soils

esidual Soils

esidual soils are found at the same location where they have been formed. Generally, the depth of residual soils variesom 5 to 20 m.

hemical weathering rate is greater in warm, humid regions than in cold, dry regions causing a faster breakdown of rocksccumulation of residual soils takes place as the rate of rock decomposition exceeds the rate of erosion or transportation

he weathered material. In humid regions, the presence of surface vegetation reduces the possibility of soil transportation

s leaching action due to percolating surface water decreases with depth, there is a corresponding decrease in the degrehemical weathering from the ground surface downwards. This results in a gradual reduction of residual soil formation wiepth, until unaltered rock is found.

esidual soils comprise of a wide range of particle sizes, shapes and composition.

ransported SoilsWeathered rock materials can be moved from their original site to new locations by one or more of the transportationgencies to form transported soils. Tranported soils are classified based on the mode of transportation and the finaleposition environment.

a) Soils that are carried and deposited by rivers are called alluvial deposits.

b) Soils that are deposited by flowing water or surface runoff while entering a lake are called lacustrine deposits.Atlern


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yers are formed in different seasons depending on flow rate.

c) If the deposits are made by rivers in sea water, they are called marine deposits. Marine deposits contain both particumaterial brought from the shore as well as organic remnants of marine life forms.

d) Melting of a glacier causes the deposition of all the materials scoured by it leading to formation ofglacial deposits.

e) Soil particles carried by wind and subsequently deposited are known as aeolian deposits.

oil compaction means increasing soil density that makes working with soil easy, helps in erecting stable

tructures, and reduces maintenance costs. Read to learn about the desirable, and undesirable, effects of

mechanical soil compaction on construction and agricultural works.

Soil Compaction

Compaction of soil brings stability and strength with it. Foundations fail most commonly because of improp

ompaction methods or poorly compacted soil that allows water to seep through the foundation and cause

tructural damage. Implementing mechanical methods to compact soil means densifying the soil, filling the

ore spaces, improving the shear resistance of soil, and providing better water movement through the soi

articles. The compaction process largely depends upon the type of soil you are dealing with because

ifferent soils have different physical properties and accordingly different compaction methods should be

dopted. Compaction also prevents frost damage of soil and increases its durability.

actors Affecting theCompaction Process

Compaction of soil depends upon various factors. Among them, grain size distribution of soil, optimum

moisture content, maximum dry density, layer thickness, and environme

actors are some of the important things to consider. Optimum moisture content(OMC) is the percentag

water present in soil mass at which a specific compaction force can dry the soil mass to its maximum dry

weight. The adjacent graph (please click to enlarge) shows that the void ratio at OMC is approximately ze

nd soil is densely compacted. For different types of soils, OMC and maximum dry density curves are

ifferent.

n the figure, W stands for water content and (d) stands for Dry Density of soil mass.


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StandardProctorandModifiedProctortests are conducted to determine OMC and the dry

ensity of soil masses. The basic difference between these two tests is the size and weight of hammer use

o compact the soil mass. The number of blows remains the same, but the falling height is changed from 1

nches to 18 inches in the Modified Proctor test. Other popular methods of determining OMC and maximu

ry density are mentioned below.

Sand Cone Test - Suitable for a large sample, delivers accurate results but requires huge area and more

time to perform.

Shelby Tube Test - Suitable for deep and under pipe haunches, not suitable for gravels and only works f

a small sample.

Nuclear Gauge Test - Statistically reliable, easy to redo and fast method.

Different Compaction Methods

Compaction of soil, in simple words, means applying external pressure to the soil mass so that its

haracteristic properties improve with regard to construction purposes. Technically speaking, staticand

ibratory forces bring soil particles together by exerting pressure on them. Static forces apply load on the

urface of soil particles, exerting dead weight of the machine in a downward direction. These forces do no

kin deep and work only for the upper surface of the soil mass.

Vibratory forces, on the other hand, work for the whole soil mass and are not limited to the upper surface

nly. Along with the dead-weight of machine, compactors and vibrators are connected that not only exertressure on the soil mass, but also shuffle the entire soil mass so that the overall soil mass is compacted

niformly. Both the top and deeper layers get blows from the vibrator and compactor resulting in denser a

ghtly packed soil.

or mechanical soil compaction, four main compaction techniques are mentioned here.

Kneading Compaction

Pressure Compaction

Vibration Compaction

mpact Compaction

Compaction equipment is selected based on the type of soil. For clayey soils, kneading techniques and

quipment have to be used because clay soils exist in the form of clods and kneading is the best way to


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reak the clods and densify clay soils. On the other hand, for granular soils, a vibratory or shaking motion

he compacting device is required so that uniform compaction is achieved. Popular compaction equipment

ypes are mentioned below.

Smooth Wheel Rollers - Single axle, equipped with a steel cylinder, sand or water are used to increase self-weight. Pushes the soil in the direction of movement and results in soil compaction.

SheepFoot Roller- Different style of sheep rollers, can be used for different types of soil, best suited fo

cohesive soils. Covers less surface area but pressure per unit area is very high resulting in healthy

compaction.

VibratoryDrum Roller- Suitable for compaction of sand, gravel, asphalt, and other heavy

aggregates.Very powerful compaction devices, provide uniformly dense soil because of vibrator attached

them.

Vibratory Padfoot Compactors - Compactors work mainly in landfill regions and padfoot compactors ha

pads attached to their drums making them work fast and deliver efficient results in confined and tight area

Tamping Foot Rollers - Basically, these devices are compactors but are popularly known as tamping

foot rollers. Kneading, impact compaction and pressure compaction happen simultaneously with these

devices.

Different classification systems divide soils according to their characteristic properties and accordingly

ompaction method is selected.

Standard Compaction Test

Equipment


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Proctor mould with a detachable collar assembly and base plate.

Manual rammer weighing 2.5 kg and equipped to provide a height of drop to a free fall of 30 cm.

Sample Extruder.A sensitive balance.

Straight edge.

Squeeze bottle

Mixing tools such as mixing pan, spoon, trowel, spatula etc.

Moisture cans.

Drying Oven

Test procedure

Obtain approximately 10 lb (4.5 kg) of air-dried soil in the mixing pan, break all the lumps so that itasses No. 4 sieve.

Add approximate amount of water to increase the moisture content by about 5%.

Determine the weight of empty proctor mould without the base plate and the collar. W1

Fix the collar and base plate

Place the first portion of the soil in the Proctor mould as explained in the class and compact the layer

pplying 25 blows.

Scratch the layer with a spatula forming a grid to ensure uniformity in distribution of compactionnergy to the subsequent layer. Place the second layer, apply 25 blows, place the last portion and apply

5 blows.


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The final layer should ensure that the compacted soil is just above the rim of the compaction mould

hen the collar is still attached.

Detach the collar carefully without disturbing the compacted soil inside the mould and using a straight

dge trim the excess soil leveling to the mould

Determine the weight of the mould with the moist soil W2, (lb). Extrude the sample and break it to

ollect the sample for water content determination preferably from the middle of the specimen.

0. Weigh an empty moisture can, W3, (g) and weigh again with the moist soil obtained from the extruded

ample in step9, W4, (g). Keep this can in the oven for water content determination

1. Break the rest of the compacted soil with hand (visually ensure that it passes USSieve No.4). Addmore water to increase the moisture content by 2%.


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2. Repeat steps 4 to 11. During this process the weight W2 increases for some time with the increase inmoisture and drops suddenly. Take two moisture increments after the weights starts reducing. Obtain

least 4 points to plot the dry unit weight, moisture content variation.

3. After 24 hrs recover the sample in the oven and determine the weight W5, (g).

Standard proctor test

soil sample I: soil sample II:

Diameter of mould, d (cm) = 10cm Wt. of rammer (kg) =2.6kgHeight of mould, h (cm) = 12.73cm No. of layers =3Volume of mould, V (cm3) = 944 cm3 No.of blows/layer =25Mass of mould, W (g) = 1933g Ht. of fall=30.48 cm


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Density determination:-

Test No. 1 2 3 4

Mass of mould + compacted soil (g) 3457.2 3721.2 3909.0 3782.5

Wt. Mass of compacted soil, Wt (g) 1524.2 1788.2 2176 2149

Bulk density,1.615 1.894 2.093 1.959

Average water content, w (%) 10 12 14 16

Dry density, (g/cc )1.50 1.71 1.86 1.69

Moisture contentdetermination:-

Objectetermination of moisture content (water content) of soil.

pparatusrying oven, Non-corrodible metal cans with lids, Balance (0.001 g accuracy for fine-grained soils), Spatula, Gloves, Ton

rocedure. Record the number of can and lid. Clean, dry, and record their weight.

. Using a spatula, place about 15-30 g of moist soil in the can. Secure the lid, weigh and record.

. Maintain the temperature of the oven at 110 5C. Open the lid, and place the can in the oven. Leave it overnight.

.After drying, remove the can carefully from the oven using gloves or tongs. Allow it to cool to room temperature.

. Weigh the dry soil in the can along with lid.

. For each soil, perform at least 3 sets of the test.


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Can No. A B C D

Test No. 1 2 3 4

Mass of can with lid, 7.78 7.83 7.71 7.9

Mass of can with lid + wet soil, 11.78 11.05 10.71 11.1

Mass of can with lid + dry soil, 11.48 10.81 10.41 10.75

Mass of water, 0.29 0.24 0.30 0.35

Mass of dry soil, 3.70 2.98 2.7 2.85

Moisture content,7.9 8.1 11.1 10.9

Optimum Moisture Content = 13.1 %

Maximum Dry Density = 1.87 g/cm3


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DENSITYDETERMINATIONOFSAMPLE2:-Test No. 1 2 3 4

Mass of mould + compacted soil (g) 5520 5625 5682 5765

Wt. Mass of compacted soil, Wt (g) 1630 1735 1792 1875

Bulk density,1.729 1.840 1.901 1.989

Average water content, w (%) 0.1062 0.1372 0.1518 0.1744

Dry density, (g/cc )1.623 1.625 1.650 1.694

MOISTURECONTENTDETERMINATIONOFSAMPLE2:-Can No. A B C D

Test No. 1 2 3 4

Mass of can with lid, 15.6 13.82 13.77 14.40

Mass of can with lid + wet soil, 45.28 42.4 54.42 57.8

Mass of can with lid + dry soil, 42.4 39.05 49.15 51.8

Mass of water, 2.88 3.35 5.27 6.0

Mass of dry soil, 26.8 25.23 35.38 37.4

Moisture content,10.74 13.27 14.89 16.04

SPECIFIC GRAVITYDETERMINATION

Purpose: This lab is performed to determine the specific gravity of soil bysing a pycnometer. Specific gravity is the ratio of the mass of unit volumef soil at a stated temperature to the mass of the same volume of gas-freeistilled water at a stated temperature.

Significance:The specific gravity of a soil is used in the phase relationship of air,


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water, and solids in a given volume of the soil.

Equipment:Pycnometer, Balance, Vacuum pump, Funnel, Spoon.

est Procedure:(1) Determine and record the weight of the empty clean and dry

ycnometer, WP.

(2) Place 10g of a dry soil sample (passed through the sieve No.10)n the pycnometer. Determine and record the weight of theycnometer containing the dry soil, WPS.

(3) Add distilled water to fill about half to three-fourth of theycnometer. Soak the sample for 10 minutes.

(4) Apply a partial vacuum to the contents for 10 minutes, to removehe entrapped air.

(5) Stop the vacuum and carefully remove the vacuum line from

ycnometer.(6) Fill the pycnometer with distilled (water to the mark), clean the

xterior surface of the pycnometer with a clean, dry cloth.Determine the weight of the pycnometer and contents, WB.

(7) Empty the pycnometer and clean it. Then fill it with distilled waternly (to the mark). Clean the exterior surface of the pycnometer

with a clean, dry cloth. Determine the weight of the pycnometernd distilled water, WA.


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(8) Empty the pycnometer and clean it.

OBSERVATIONAND CALCULATIONWt. of soil (gm.) = 200 gm.

Test No. Sample 1 Sample 2

ycnometer / Density bottle No.1 2

Mass of pycnometer, W1 (g) 687 gm. 687 gm.

Mass of pycnometer + dry soil, W2 (g) 887 gm. 887 gm.

Mass of pycnometer + soil + water, W3 (g)

1684 gm. 1683 gm.Mass of pycnometer + water, W4 (g) 1564 gm. 1564 gm.

pecific gravity ofsoil,

GS= (W2-W1)/{(W2-W1)-(W3-W4)} 2.5 2.4691

Result:-Specific gravity of soil sample 1 = 2.5

Specific gravity of soil sample 2 = 2.4691


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ATTERBERG LIMITS :-

ObjectDetermination of the liquid and plastic limits of a soil.

pparatusLiquid limit device and grooving tools, Metal rod of 3 mm diameter, Apparatus for moisture content

etermination, Porcelain evaporating dish, Spatula, Wash bottle filled with distilled water, Measuring cylinder, Glassate.

rocedure for Liquid Limit1. Take about 150 gm of dry soil passing 425 micron sieve,and mix it with distilled water in a porcelain dish to

orm a uniform paste.

2. Place a portion of the paste in the cup of liquid limit device with a spatula, press the soil down to remove airockets, spread it to a maximum depth of 10 mm, and form an approximately horizontal surface.

3. By holding a grooving tool perpendicular to the cup, carefully cut through the sample from back to front, andorm a clean straight groove in the centre by dividing into two halves.

4. Turn the crank handle of the device at a steady rate of two revolutions per second. Continue turning until thewo halves of the groove is closed along a distance of 13 mm. Record the number of blows to reach this condition.

5. Take about 15 gm of the soil from the joined portion of the groove to a moisture can for determining waterontent.

6. Transfer the remaining soil from the cup into the porcelain dish. Clean and dry the cup and the grooving tool

7. Repeat steps 2 to 6, and obtain at least four sets of readings evenly spaced out in the range of 10 to 40ows.

rocedure forPlastic Limit1. Use the remaining soil from the porcelain dish.

2. Take about 10 gm of the soil mass in the hand, form a ball, and roll it between the palm or the fingers andhe glass plate using complete motion of the hand forward and reverse.

3. Apply only sufficient pressure to make a soil thread, and continue rolling until a thread of 3 mm diameter isormed. Comparison can be made with the metal rod.

4. If the diameter becomes less than 3 mm without cracking, turn the soil into a ball again, and re-roll. Repeathis remoulding and rolling process until the thread starts just crumbling at a diameter of 3 mm.

5. Gather the pieces of crumbled thread and place them in a moisture can for determining water content.

6. Repeat steps 2 to 5 at least two more times with fresh samples of 10 gm each.


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Determination of Liquid Limit

Test No. 1 2 3 4

No. of blows 31 29 20 14

Can No. 11 1 5 4

Mass of can (g) 22.23 23.31 21.87 22.58

Mass of can + wet.soil, (g) 28.56 29.27 25.73 25.22

Mass of can + dry soil, (g) 27.40 28.10 24.90 24.60

Mass of water (g) 1.16 1.17 0.83 0.62

Mass of dry soil (g) 5.03 4.79 3.03 2.02

Water content (%) 23.06 24.43 27.39 30.69

Liquid Limit = Water content corresponding to 25 blows=26%

Determinationof Plastic Limit

Test No. 1 2 3

Can No. 7 14 13

Mass of can (g) 7.78 7.83 15.16

Mass of can + wet soil, (g) 16.39 13.43 21.23Mass of can + dry soil, (g) 15.28 12.69 20.43

Mass of water (g) 1.11 0.74 0.8

Mass of dry soil (g) 7.5 4.86 5.27

Water content (%) 14.8 15.2 15.1

Plastic Limit = Average of the computed water contents =15, Plasticity Index = LL-PL= 11


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PARTICLESIZEDISTRIBUTION

ObjectDetermination of quantitative size distribution of particles of soil down to fine-grained fraction.

ApparatusSet of sieves (4.75 mm, 2.8 mm, 2 mm, 1 mm, 600 micron, 425 micron, 300 micron, 150 micron, 75 micro

alance (0.1 g accuracy), Drying oven, Rubber pestle, Cleaning brush, Mechanical shaker.

Procedure1. Take a suitable quantity of oven-dried soil. The mass of soil sample required for each test depends on t

maximum size of material.

2. Clean the sieves to be used, and record the weight of each sieve and the bottom pan.

3. Arrange the sieves to have the largest mesh size at the top of the stack. Pour carefully the soil sample he top sieve and place the lid over it.

4. Place the sieve stack on the mechanical shaker, screw down the lid, and vibrate the soil sample for 10minutes.

5. Remove the stack and re-weigh each sieve and the bottom pan with the soil sample fraction retained o

OBSERVATIONTABLEInitial mass of soil sample taken for analysis (kg) =1 kg

Sieve size

(mm)

Particle size

(mm)

Soil retained

(g)

Cumulativesoil retained

(g)

Percentretained

(%)

Percent finer

(%)

4.75 mm 4.75 47.5 47.5 4.75 95.25

2 mm 2 98.5 146 14.6 85.4

1 mm 1 167 313 31.3 68.7

600 micron 0.6 115 428 42.8 57.2

425 micron 0.425 122 550 55 45

212 micron 0.212 216.5 766.5 76.65 23.35

150 micron 0.15 92.5 859 85.9 14.1

75 micron 0.075 108 967 96.7 3.3

Pan 0 31 998 99.8 0.2

1.Obtain the mass of soil retained on each sieve. The sum of the retained masses should be approximately equhe initial mass of the soil sample.

2. Calculate the percent retained on each sieve by dividing the mass retained on the sieve with the total initial maf the soil.

3. Calculate the cumulative percent retained by adding percent retained on each sieve as a cumulative procedure


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4. Calculate the percent finer by subtracting the cumulative percent retained from 100 percent.

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

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


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project on soil

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