Correlation of liquid limit using Cone penetrometer and Casagrande apparatus

CHAPTER 1INTRODUCTION

1.1 General

The liquid limit test, first proposed by Atterberg in 1911 and later

standardized by Casagrande (1932, 1958), is one of the oldest and most

commonly used soil test for the classification of fine grained soils in

geotechnical engineering. In addition, a number of engineering properties of

soils, such as untrained shear strength, compressibility, permeability, swelling

behavior, surface area, cat ion exchange capacity and liquefaction have direct

or indirect correlations with the liquid limit value.

Two methods are used to determine the liquid limit of soils, namely the

Casagrande method and cone penetration method. Although the cone

penetration method was accepted as the standard method in many countries,

e.g. UK, India and Canada, the Casagrande method is still widely used.

British Standards (BS1377: Part 2, 1990) give the cone penetration method as

the “definitive” method and the Casagrande method as an alternative”.

However, the American Society for Testing and Materials (ASTM D 4318-

2000) recommend the Casagrande method. The important difference is that

the Casagrande apparatus defined in BS 1377: Part 2 (1990) has a relatively

softer base than that defined in ASTM (D 4318-2000). In practice, both types

of Casagrande apparatus are being used in geotechnical engineering in

different parts of the world.

1.2 Desirable properties of soil

Stability

Incompressibility

Permanency of strength

Minimum change in volume and stability under adverse condition

Ease of compaction

RASTA – CENTRE FOR ROAD TECHNOLOGY Page 1


1.3 Objective of present study

i) To establish the fundamental criteria for liquid limit using Casagrande

apparatus.

ii) To establish the fundamental criteria for liquid limit using Cone

penetrometer.

iii) To compare the liquid limit obtained from Casagrande apparatus and

Cone penetrometer.

1.4 Scope of present study

Present study deals with the correlation of liquid limit values obtained from

Casagrande apparatus and Cone penetrometer.



CHAPTER 2LITERATURE REVIEW

2.1 GeneralThe engineering behavior of fine grained soil depends on factors other than

particle size distribution. It is influenced primarily by their mineral and

structural composition and the amount of water they contain, which referred

as moisture content on fine grained soils and help to classify fine grained soils

and help to classify fine grained soils and also to assess their mineral

composition and engineering properties.

The liquid limit and plastic limit are known collectively as the Atterberg limits,

after the Swedish scientist Dr A.Atterberg, who first defined them for the for

the classification of agricultural soils in 1911. Originally they were determined

by means of simple hand test using an evaporating dish. The procedures

were defined more precisely for engineering purposes by professor

A.Casagrande in 1932. The mechanical device he designed for determining

the liquid limit is still known as the Casagrande apparatus, although more

recently a cone penetration apparatus has been developed for routine use.

The tests for determining the liquid and plastic limits are specified in BS

1377:1975 and the most widely used of the index test.

(Reference 1)

The liquid limit of a soil can be determined using the cone penetrometer or the

Casagrande apparatus (BS 1377:1990: part 2, clauses 4.3, 4.5). One of the

major changes introduced by the 1975 British Standard (BS 1377) was that

the preferred method of liquid limit testing became the cone penetrometer.

This preference is reinforced in the revised 1990 British Standard which refers

to the cone penetrometer as the ‘definitive method’. The cone penetrometer is

considered a more satisfactory method than the alternative because it is

essentially a static test which relies on the shear strength of the soil, whereas

the alternative Casagrande cup method introduces dynamic effects. In the

penetrometer test, the liquid limit of the soil is the moisture content at which



an 80 g, 300 cone sinks exactly 20 mm into a cup of remolded soil in a 5s

period. At this moisture content the soil will be very soft. When determining

the liquid limit with the Casagrande apparatus, the base of the cup is filled

with soil and a groove is then made through the soil to the base of the cup.

The apparatus is arranged to allow the metal cup to be raised repeatedly

10mm and dropped freely on to its rubber base at a constant rate of two drops

per second. The liquid limit is the moisture content of a soil when 25 blows

cause 13mm of closure of the groove at the base of the cup. The liquid limit is

generally determined by mixing soils to consistencies just wet and dry of the

liquid limit and determining the liquid limit moisture content by interpolation

between four points BS 1377: part 2:1990, clause 4.6 provides factors which

allow the liquid limit to be determined from one point (Clayton and Jukes

1978)

The plasticity of soils is determined by using relatively simple remolded

strength tests. The plastic limit is the moisture content of the soil under test

when remolded and rolled between the tips of the fingers and a glass plate

such that longitudinal and transverse cracks appear at a rolled diameter of 3

mm. At this point the soil has a stiff consistency.

2.2Influence of Testing Method in the Determination of Liquid Limit(reference 2)Conventionally, the Casagrande method has been widely used for

determining the liquid limit of soils. However, numerous shortcomings in

Casagrande method have been recognized such as reliability, reproducibility

and variation of apparatus (Soweretal., 1959, Casagrande, 1958, Sherwood &

Ryley, 1970). The fall cone method, which originated in Sweden in 1915, had

been proposed as an alternative method to determine the liquid limit to

overcome these shortcomings. In BS 1377 (1990), both Casagrande and fall

cone method are permitted as liquid limit test while ASTM (1993) only

recognized the Casagrande method. However, it is well recognized that

Casagrande and fall cone method yield different results (e.g. Sherwood &

Ryley, 1970, Wood, 1982, Leroueil & Le Bihan, 1996, Shibata & Nishihara,

1997, etc.).Liquid limit for PT clay in this study was determined by



Casagrande method by PARI while liquid limit for other data set that will be

used to supplement the analysis of this study was determined by fall cone

method. In addition, the intrinsic framework proposed by Leroueil et al. (1983)

was based on fall cone liquid limit and no clear definition of liquid limit was

given in Burland (1990)’s intrinsic framework (Eq. 2.5 and Eq. 2.6). Therefore,

it would be useful to express the relationship between Casagrande and fall

cone liquid limit value for making possible their mutual conversion so that data

from different sources could be compared consistently. Although some

relationship between Casagrande and fall cone liquid limit value had been

proposed in the literatures, no systematic study has been undertaken to

establish if these proposed relationships are applicable to Singapore marine

clay. More importantly, it would provide a basis for the evaluation of the

applicability of Leroueilet al. (1983) and Burland (1990) intrinsic framework in

PT clay in the next section.

2.3Relationship between LLCasagrande and LLcone

Numerous studies have been conducted in many countries to compare the

Casagrande fall cone liquid limit values and various relationships had been

proposed and summarized in Table 4.4. All relationship is obtained by linear

regression except the relationship proposed by Shibata & Nishibara (1997).

They derived the relationship for British cone and Swedish cone by studying

the general characteristics of fall cone penetration in soils with different

Casagrande liquid limit. However, these reported experiments were

conducted in accordance to different standards with different device

specification (either Casagrande apparatus or cone penetrometer) and

different liquid limit definition (see Tables 4.4 and 4.5), which had been proven

to have an effect on the measured liquid limit values. A clear example was

given in Table 4.4 in which the relationship proposed by Wasti & Bezirci

(1985) is not consistent with the others. Their fall cone liquid limit values were

higher than the Casagrande liquid limit values. In their paper, they stated that

the Casagrande device they used in their experimental program has a harder

base than the other studies. Thus, in this study, only relationship proposed by

Sherwood & Ryley (1970), Budhu (1985) and Shibata & Nishibara (1999) will



be examined with the data in PT clay, as they were determined in accordance

to British Standard. In order to establish the relationship between Casagrande

liquid limit (LLCasagrande) and fall cone liquid limit (LLcone) for PT clay,

Casagrande and fall cone method have been used to determine the liquid limit

for seven soil samples taken from seabed near Pulau Tekong. The samples

were obtained from upper and lower PT clay layer. The Casagrande device,

fall cone and testing procedures are in accordance to BS 1377: 1990 (Part 2:

4.3 and 4.5). In order to obtain representative properties of natural soil, the

soil samples were tested without drying. All tests were performed by the same

person and same equipments to avoid operator and equipment error. The

liquid limit values are reported as the average of three tests. The relationship

and difference between the LLCasagrande and LLcone for the tested PT clay

is shown in Figure 4.2 and Figure 4.3, respectively. Data from literatures were

also plotted for comparison. In Figure 4.2, it is clearly shown that fall cone

method yields lower liquid limit than Casagrande method in PT clay. The

LLCasagrande for the tested soil samples are ranging from 54% to 138%

while the LLcone for the tested soil samples are ranging from 51% to 117%.

These data in PT clay generally agreed well with the data reported by

Sherwood & Ryley (1970) and Budhu (1985) except one data point with the

LLCasagrande of 138%. Figure 4.3 shows that the differences between

LLCasagrande and LLcone for PT clay increase from 2% to 22% with

increasing LLCasagrande. Similar trends were also observed from other data

reported in literatures. It might also be noticed in Figure 4.2 and Figure 4.3

that fall cone method generally yields lower liquid limit than Casagrande

method when the LLCasagrande exceeds about 50%.Among the published

relationships shown in Figure 4.2, the relationship proposed by Shibata &

Nishibara (1997) appears to give a slightly better conversion between two

liquid limit values in PT clay with the average error less than 2%.However,

these relationships should be used with care as it had been shown in the

literature that the relationship begins to deviate considerably from linearity

when the LLCasagrande exceeds 100% (Skopek & Ter-Stepanian, 1975,

Littleton & Farmilo, 1977,Wasti & Bezirci, 1985). These observations might

explain the deviation of the data point with the LLCasagrande of 138% from

trend for the data set reported by Sherwood &Ryley (1970) and Budhu (1985).



However, the liquid limit for PT clays is generally less than 100%. Hence,

these published linear relationships, particularly the one proposed by Shibata

& Nishibara (1997), are probably sufficiently accurate for the practice.

2.4Cause(s) of the Difference between LLCasagrande and LLcone

Several proposals could be found in the literature on the cause(s) of the

difference between LLCasagrande and LLcone. Budhu (1985) observed that

the relationship between LLCasagrande and LLcone appears to be influenced

by the clay fraction (percentage by the weight of particle finer than 2 μm) of

the soil. He observed that the LLcone is higher than LLCasagrande when the

clay fraction of the soil specimen is lower than 50%.However the

representation of cohesive soil behavior with the clay fraction is rather crude

as not all the soil particle less than 2 μm is true clay mineral. On the other

hand, Sridhar an and Prakash (1998) suggested that in addition to the clay

fraction, the dominant clay mineral type might also play a role in determining

the relationship between the LLCasagrande and LLcone. They observed that

the fall cone method yields a higher liquid limit than the Casagrande method

for kaolinitic soils while the Casagrande method yields higher liquid limit than

fall cone method for montmorillonitic soils. However, the present study shows

that the Casagrande method yields a higher liquid limit than fall cone method,

although the dominant mineral in PT clay is kaolinite (Tan et al., 2002b).

Leroueil & Le Bihan (1998) has opined that the dominant clay mineral type is

probably not the only factor that governing this difference between

LLCasagrande and LLcone. As a summary, attempts to account for the

difference using clay fraction and clay mineralogy appear to be not quite

successful. Based on the data reported by Youssef et al. (1965) and

Sherwood & Ryley (1970), Wood (1982) suggested that the difference in the

liquid limit values is attributed to decreasing remoulded undrained shear

strength (sur) at LLCasagrande as the liquid limit increases. To examine this

behaviour in PT clay, a method of correlating cone penetration with sur is

required because laboratory vane shear tests were not performed on the PT

clay samples in conjunction with the liquid limit test. Hansbo (1957) made an

extensive study of cone penetration testing with the Scandinavian fall cone



device. He attempted to correlate penetrations of essentially four different

cones (60º cones weighing 10g and 60g and 30º cones weighing 100g and

400g) with field vane shear strengths of a number of Scandinavian,

particularly Swedish soils. He established the following relationship, which can

also be deduced from dimensional analysis (Wood & Wroth, 1978):

Su = Kmg/d*d (4.1)

Where,

Su is the undrained shear strength of the clay, kPa;

m is the mass of the cone, g;

g is the acceleration due to gravity (9.81 m/s2);

d is the depth of penetration of the cone in the soil, mm and

K is a constant, a function of the apex angle of the cone tip, the cone surface

roughness and the rate of shear strain during penetration (Houlsby, 1982,

Koumoto & Houlsby, 2001).

For remoulded clays, Karlsson (1977) suggested K values of 0.8 and 0.27 for

cone with an apex angle of 30and 60, respectively. Wood (1985) also

suggested a very similar value of 0.85 and 0.29, respectively. In Figure 4.4,

LLCasagrande is indicated by the solid circle. As indicated in Figure 4.4, the

depth of cone penetration increases from 21.9 to 35.2 mm when the

LLCasagrande increases from 54% to 138%. Using Eq.4.1 and K = 0.85 as

suggested by Wood (1985), this corresponds to a decrease in sur at

LLCasagrande from 1.39 kPa to 0.54 kPa. Such a variation in sur at

LLCasagrande is similar to that observed on the basis of vane shear tests

reported by Youssef et al. (1965) in which sur at LLCasagrande decreases

with increasing LLCasagrande.In order to compare the data in present study

with the published data, Figure 4.5 was reinterpreted after Wood (1982) using

K = 0.85 in Eq. 4.1, instead of K = 1.2 adopted by Wood (1982), to convert sur

at LLCasagrande data from Youssef et al. (1965) to the corresponding depths

of cone penetration and depth of cone penetration data from Sherwood &

Ryley (1970) to the corresponding sur at LLCasagrande. Figure 4.5a shows

the variation of undrained shear strength at LLCasagrande with



LLCasagrande while Figure 4.5b shows the variation of depth of cone

penetration at LLCasagrande with LLCasagrande. The data from Youssef et

al. (1965) show a slight systematic difference from the other two data sources.

This might be due to the use of a Casagrande device that does not comply

fully with that specified in BS 1377 (1990). Although a significant amount of

scatter is observed, the PT clay data follow the general trend reported by

Sherwood & Ryley (1970), i.e. there is neither a single depth of cone

penetration nor a single undrained shear strength associated with

LLCasagrande.

For a 30/80 g fall cone with a depth of cone penetration = 20 mm (i.e. at

LLcone), the value of sur calculated using Eq. 4.1 with K = 0.85 would be 1.67

kPa.Lines corresponding to sur = 1.67 kPa and depth of cone penetration =

20 mm representing LLcone are shown in Figures. 4.5a and 4.5b for

reference, respectively. The general trends shown in these figures are similar

to that shown in Figure 4.3, indicating that Wood (1982)’s hypothesis is

probably valid for PT clay as well.



CHAPTER 3METHODOLOGY

3.1 Testing of selected materials:Various lab tests that are conducted on the soil samples are as follows:

Grain size analysis

Atterberg limits using

Casagrande apparatus

Cone penetrometer

3.2 Grain size analysis [As per IS: 2720 (Part 4) - 1985]

Fig.1

Preparation of sample

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 re-moved 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 of 500g is taken in tray and soaked with water, The

soaking of soil continued for 10 -12 hours.

2. Sample is washed through 0.075 mm IS sieve with water till substantially

clean water comes out. Retained sample on 0.075 mm IS sieve shall be oven

dried for 24 hours.

3. 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 4.75mm,

2.36mm, 1.18mm, 0.60mm, 0.425mm, 0.15mm and0.075mm IS sieves. Soil

retained on each sieve is weighed.

3.3 Atterberg limit

By consistency is meant the relative ease with which soil can be deformed.

This term is mostly used for fine grained soils for which the consistency is

related to a large extent to water content.consistancy denotes the degree of

firmness of the soil which may be termed as soft, firm, stiff or hard. In 1911

Atterberg divided the entire range from liquid to solid state. he set arbitrary

limits known as consistency limits or Atterberg limits, for these divisions in

terms of water content. Thus the consistency limits are the water contents at

which the soil mass passes from one state to the next.

Liquid Limit Test

A) Cone penetrometer Equipments 1. A flat glass plate.

2. Two spatulas.

3. Penetrometer



4. A cone of stainless steel approximately 35 mm long, with smooth, polished

Surface and an angle of 30 +1

5. One or more metal cups not less than 55 mm in diameter and 40 mm deep

with the rim parallel to the flat base.

6. Apparatus for moisture content determination (moisture tin and oven).

7. A wash bottle containing distilled water.

Test procedures

1. Take a sample of about 300 g from the soil which passing 425 mm sieve.

2. Place the soil sample on the glass plate and mix well with distilled water

using spatulas until it becomes paste from. If necessary, add more water so

that the first cone penetration reading is about 15 mm.

3. Push a portion of the mixed soil into the cup with spatulas taking care not to

trap air. Strike off excess soil with straightedge to give a smooth level surface,

4. With the penetration cone locked in the raised position lower the supporting

Assembly so that the tip of the cone just touches the surface of the soil. When

the cone is in the correct position a slight movement of the cup will just mark

The soil surface. Lower the stem of the dial gauge to contact the cone shaft

and record the reading on the dial gauge to the nearest 0.1 mm.Release the

cone for about period of 5 second. After locking the cone in

5. Position lower the stem of the dial gauge to contact the cone shaft and

record The reading of the dial gauge to the nearest 0.1 mm. record the

difference between beginning and the end of the drop as the cone

penetration.

6. Take about 10 gram of the soil specimen from the cup to determine its

moisture content.

7. Repeat the same procedure for at least 4 times using same specimen with

adding more distilled water. Choose for the specimen that only shows the

reading between 14 mm to 28 mm.

8. Plot a graph of moisture content versus penetration. Moisture content

corresponding to penetration of 20 mm is the Liquid Limit (LL).



B) Casagrande apparatusEquipment: Liquid limit device, Porcelain (evaporating) dish, Flat grooving tool with gage,

Eight moisture cans, Balance, Glass plate, Spatula, Wash bottle filled with

distilled water, drying oven set at 105 C.

Fig.2

Test Procedure:

(1) Take roughly 3/4 of the soil and place it into the porcelain dish. Assume

that the soil was previously passed though a No. 40 sieve, air-dried, and then

pulverized. Thoroughly mix the soil with a small amount of distilled water until

it appears as a smooth uniform paste. Cover the dish with cellophane to

prevent moisture from escaping.



(2) Weigh four of the empty moisture cans with their lids, and record the

Respective weights and can numbers on the data sheet.

(3) Adjust the liquid limit apparatus by checking the height of drop of the

cup. The point on the cup that comes in contact with the base should rise to a

height of 10mm. The block on the end of the grooving tool 10 mm high and

should be used as a gage. Practice using the cup and determine the correct

rate to rotate the crank so that the cup drops approximately two times per

second.

(4) Place a portion of the previously mixed soil into the cup of the liquid limit

apparatus at the point where the cup rests on the base. Squeeze the soil

down to eliminate air pockets and spread it into the cup to a depth of about 10

mm at its deepest point. The soil pat should form an approximately horizontal

surface (See Photo B).

(5) Use the grooving tool carefully cut a clean straight groove down the

center of the cup. The tool should remain perpendicular to the surface of the

cup as groove is being made. Use extreme care to prevent sliding the soil

relative to the surface of the cup (See Photo C).

(6) Make sure that the base of the apparatus below the cup and the

underside of the cup is clean of soil. Turn the crank of the apparatus at a rate

of approximately two drops per second and count the number of drops, N; it

takes to make the two halves of the soil pat come into contact at the bottom of

the groove along a distance of 13 mm (1/2 in.) (See Photo D). If the number

of drops exceeds 50, then go directly to step eight and do not record the

number of drops, otherwise, record the number of drops on the data sheet.

(7) Take a sample, using the spatula, from edge to edge of the soil pat. The

sample should include the soil on both sides of where the groove came into

contact. Place the soil into a moisture can cover it. Immediately weigh the

moisture can containing the soil, record its mass, remove the lid, and place



the can into the oven. Leave the moisture can in the oven for at least 16

hours. Place the soil remaining in the cup into the porcelain dish. Clean and

dry the cup on the apparatus and the grooving tool.

(8) Remix the entire soil specimen in the porcelain dish. Add a small amount

Of distilled water to increase the water content so that the number of drops

req to close the groove decrease.

(9) Repeat steps six, seven, and eight for at least two additional trials

producing successively lower numbers of drops to close the groove. One

of the trials shall be for a closure requiring 25 to 35 drops, one for closure

between 20 and 30 drops, and one trial for a closure requiring 15 to 25

drops. Determine the water content from each trial by using the same

method used in the first laboratory. Remember to use the same balance

for all weighing.



CHAPTER 4TEST RESULTS

4.1 Grain size analysisTable.1

Table.2

Weight of sample taken: 500g MH&OH

Sieve size %fine passing

g

Remark%

4.75mm 95.78 Gravel4.222.36mm 94.28

1.18mm 91.16 Sand10.740.60mm 89.76

0.425mm 88.26 Fines85.040.150mm 86.92

0.075mm 65.04Table.3

Fig.3


Sl no Test

Results

MH&OH%

SC%

SP%

1 Grain size analysis

Gravel 4.22 Gravel 4.96 0.954

Sand 10.75 Sand 65.66 71.458

Fines 85.04 Fines 29.36 27.58

1Test

Results of Liquid Limit

MH&OH%

SC%

SP%

Casagrande 59 29 17

Cone

Penetrometer

66 32 26


Weight of sample taken: 500g SC

Sieve size % fine passing

g

Remark%

4.75mm 95.04 Gravel4.962.36mm 90.76

1.18mm 75.92 Sand65.660.60mm 61.28

0.425mm 48.24 Fines29.360.150mm 33.75

0.075mm 29.38

Table.4



Fig.4

Weight of sample taken: 500g SP

Sieve size % fine passing

g

Remark%

4.75mm 99.046 Gravel0.9542.36mm 97.796

1.18mm 85.21 Sand71.4580.60mm 46.522

0.425mm 35.916 Fines25.280.150mm 32.774

0.075mm 27.588

Table.5



Fig.5



Liquid limit

MH&OH

Table.6

LIQUID LIMIT


DEPTHIN mm

M/CIN (%)

14.1 59.94

15.0 61.35

15.6 61.67

16.9 62.84

20.1 65.84

22.2 67.24

22.8 61.35

23.4 61.67

23.9 62.84

25.4 59.94

Fig:6 Showing Liquid limit of MH&OH(Cone penetrometer)


MH&OH

Table.7

56.00

57.00

58.00

59.00

60.00

61.00

62.00

63.00

0 5 10 15 20 25 30 35 40 45NO OF BLOWS

M/C

(%)

Series1

Liquid limit


BLOWSIN no’s

M/CIN (%)

12 62.16

15 60.11

18 59.65

21 58.92

25 58.48

29 58.21

31 58.10

33 57.82

36 57.50

39 56.30

Fig:7 Showing Liquid limit of MH&OH(Casagrande)


Clayey sand (SC)

Table.8

28.5

29

29.5

30

30.5

31

31.5

32

32.5

33

0 50 100 150 200 250 300

Series1

Liquid limit


DEPTHIN mm

M/CIN (%)

14.3 29.08

15.6 29.39

17.2 30.16

18.1 31.01

19.0 31.43

20.0 31.87

21.3 32.09

21.9 32.16

25.8 32.78

Fig:8 Showing Liquid limit of SC(Cone penetrometer)


Clayey sand (SC)

Table.9

26

27

28

29

30

31

32

0 5 10 15 20 25 30 35 40

NO OF BLOWS

MC

(%)

Poorly graded sand (SP)


BLOWSIN no’s

M/CIN (%)

10 31.14

14 30.88

15 30.77

20 30.03

22 29.89

24 29.71

26 28.58

29 28.17

32 27.28

Fig:9 Showing Liquid limit of SC(Casagrande)


Table.10

Poorly graded sand (SP)


DEPTH IN mm

M/C IN (%)

14.3 23.70

15.2 24.13

16.8 24.3

19.1 25.2

21.0 26.01

22.6 26.25

24.0 26.8

25.8 27.3

26.4 27.5

27.6 27.82

Fig:10 Showing liquid limit of SP(Cone penetrometer)


Table.11

0

5

10

15

20

25

30

0.00 5.00 10.00 15.00 20.00 25.00 30.00

NO OF BLOWS

M/C

(%)

CORRELATION CHART


No of Blows M/C(%)

2 28.45

4 25.1

6 23.47

15 20.99

18 20..61

22 18.10

28 16.20

Fig:11 Showing liquid limit of SP(Casagrande)


Cone penetrometer vs Casagrandey = 0.9872x + 6.7821

R2 = 0.9801

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60 70

LL - Casagrande

LL -

Cone

pene

trom

eter

Fig.12

M/C vs LL

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

M/C

LL Casagrande

Conepenetrometer

Fig.13



CONCLUSIONFrom the tests conducted and the results obtained using Casagrande and Cone

penetrometer it can be concluded that the variation in terms of percentage in the

Liquid Limit is observed and is given as follows:

For Poorly graded sand percentage variation obtained was 35% with respect to

Casagrande.

For Clayey sand percentage variation obtained was 10% with respect to

Casagrande.

For Inorganic silt and Organic clay percentage variation obtained was 11% with

respect to Casagrande.



REFERENCES

1) Engineering Properties of Soils Based on Laboratory TestingProf. Krishna Reddy, UIC.2) Journal of Islamic Academy of Sciences 1:1, 74-78, 1988.3) INTRINSIC FRAMEWORK OF PULAU TEKONG CLAY.4) Soil mechanics. Dr B C Punmia.5) IS 2720 (part-5) 19856) IS 11196 1985


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