ESTIMATION OF BEARING CAPACITY OF BLACK COTTON SOIL · PDF fileEstimation of Bearing Capacity...

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International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 10, October 2017, pp. 886–895, Article ID: IJMET_08_10_096

Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=10

ISSN Print: 0976-6340 and ISSN Online: 0976-6359

© IAEME Publication Scopus Indexed

ESTIMATION OF BEARING CAPACITY OF

BLACK COTTON SOIL USING ROCK DUST

AND GEO-TEXTILE SHEET: AN

EXPERIMENTAL STUDY

N. Vijay Kumar

Research Scholar, Department of Civil Engineering, K L University,

Vaddeswaram, Guntur, Andhra Pradesh, India

SS.Asadi

Associate Dean Academics & Professor, Department of Civil Engineering,

K L University, Vaddeswaram, Guntur,Andhra Pradesh, India

A.V.S. Prasad

Professor, Department of Civil Engineering, K L University,

Vaddeswaram, Guntur, Andhra Pradesh, India

ABSTRACT

While increasing of population its effects on reduction of available land as its

decrease softness of soil and become weak due to construction of heavy buildings and

civil engineering structures etc. soil is a natural resource and it is widely available on

the land and in civil engineering structures have to be carried out on weak or less

bearing soils. Owing such soil poor shear strength and high swelling and

enlargement, a great diversity of ground modification techniques such as soil

stabilization and reinforcement are employed to improve mechanical behavior of

soils, thereby escalate the reliability of construction. The meticulous stabilization of

substructure soils constitutes an increasingly important issue in the present in civil

engineering world. This present study carried out with intension to evaluate the effects

of quarry dust and Geotextile on the geotechnical properties of the locally available

expansive soil from Hyderabad city. Tests which are to be carried out on the sample

dispense with specific gravity, compaction, CBR. These tests are to be conducted at by

adding 5%, 10%, 15% of quarry dust and placing Geotextile sheet at the depth of

50mm, 100mm, and 150mm from the top.

Keywords: Geosynthetic materials BC soil, Particle size Distribution, California

bearing ratio.

N. Vijay Kumar, SS.Asadi and A.V.S. Prasad


Cite this Article: N. Vijay Kumar, SS.Asadi and A.V.S. Prasad, Estimation of

Bearing Capacity of Black Cotton Soil Using Rock Dust and Geo-Textile Sheet: An

Experimental Study, International Journal of Mechanical Engineering and Technology

8(10), 2017, pp. 886–895.

http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=10

1. INTRODUCTION

In Civil engineering practice the load from super structure is to be transferred to a soil layer

through footing that is capable to withstand this load with adequate factor of safety under

tolerable settlement. There are various sub soils such as soft marine clay, new born sandy area

by dunes, reclaimed land where in adequately strong layer may not be available at shallow

depth. It becomes therefore necessary to transfer the load at a great depth where strong

bearing layer is available by adopting pile foundation, pier foundation, cassion foundation.

This method of insertion of structural component into the soil medium is highly expensive

and installation causes many practical complications. If this soft soil medium is not too deep,

stone columns, lime piles and other stabilization techniques such as grouting, vibro-flotation,

compaction piles are also in common. These methods are also proved to be uneconomical,

time consuming and laborious.With the investigation made on use of geosynthetics for the

purpose of improvement of sub-soil properties, soil reinforcement by geotextile,

geomembrane, geogrids and geocomposits has gained momentum. It is claimed that use of

geosynthetics as soil reinforcement has many advantages over conventional soil improvement

method. In that it is less expensive, easy to construct and highly effective in improving the

soil properties Due to reasons stated above, research work on reinforced soil in different

disciplines of geotechnical construction has been under taken all over the world. (Dembiki et

al (1988), Haroon et al (1990), Ingar (1990). In our country, 9excellent research work has

been under taken since last four decades Murthy and Shridharan 1988, Verma and Char 1986.

2. OBJECTIVES OF THE STUDY

1. To study the effect of quarry dust column encased with geosynthetic in improving the

strength characteristics of black cotton soil.

2. To study the load bearing capacity of geosynthetic encased quarry dust columns with

single columns and predict the settlement reduction factor of reinforced ground with

the un reinforced ground.

3. Soil is good in compression and weak in tensile strength and even soil don’t have

tensile strength naturally therefore the weakness of soil takes place to reduce the

weakness of soil reinforcement is made and its improved strength characteristics is

studied.

3. METHODOLOGY

3.1Materials used

3.1.1 Stone dust

The stone dust is a waste product produced in granite industry while cutting huge granite

rocks to the desired shapes. About 3000 metric ton of granite dust/slurry is produced per day

as a by- product during manufacturing of granite tiles and slabs from the raw blocks. The

granite cutting industries are dumping these wastes in nearby pits or open lands. This leads to

serious environmental pollution and occupation of vast area of land especially after the slurry

dries up. Stabilization of expansive soils using admixtures controls the adverse effects on the

Estimation of Bearing Capacity of Black Cotton Soil Using Rock Dust and Geo-Textile Sheet: An

Experimental Study


foundations and structures. Experimental studies have been carried out in the laboratory by

adding admixtures like stone dust to the expansive soils at different proportions. This study

envisages the effect of stone dust on compaction characteristics (OMC & MDD) and

California bearing ratio (CBR) of black cotton soil and 5%, 10%, and 15% stone dust by

weight of dry soil.

Figure 1.2.1 stone dust at Railapur village.

3.1.2 Geosynthetic

The investigation made on use of geosynthetic for the purpose of improvement of sub-soil

properties, soil reinforcement by Geotextile, Geomembrane, Geogrids and Geocomposits has

gained momentum. It is claimed that use of geosynthetic as soil reinforcement has many

advantages over conventional soil improvement method. In that it is less expensive, easy to

construct and highly effective in improving the soil properties.

Figure 1.5.1 Geotextile

3.2 Process of the methodology

3.2.1 Determination of (California Bearing Ratio) CBR of soil in re-moulded condition

In this the following equipments are used Compression machine, Proving ring, Dial gauge,

Timer Sampling tube, Split mould, Verniercaliper, Balances

Figure 1 CBR Test Setup.



The dry density for remoulding should be either the field density or if the sub grade is to

be compacted, at the maximum dry density value obtained from the Proctor Compaction test.

If it is proposed to carry out the CBR test on an unsoaked specimen, the moisture content for

remoulding should be the same as the equilibrium moisture content which the soil is likely to

reach subsequent to the construction of the road. If it is proposed to carry out the CBR test on

a soaked specimen, the moisture content for remoulding should be at the optimum and soaked

under water for 96 hours.Soil Sample–The material used in the remoulded specimen should

all pass through a 19 mm IS sieve. Allowance for larger material may be made by replacing it

by an equal amount of material which passes a 19 mm sieve but is retained on a 4.75 mm IS

sieve. This procedure is not satisfactory if the size of the soil particles is predominantly

greater than 19 mm. The specimen may be compacted statically or dynamically.

3.2.2 Compaction by Dynamic Method

For dynamic compaction, a representative sample of soil weighing approximately 4.5 kg or

more for fine grained soils and 5.5 kg or more for granular soil shall be taken and mixed

thoroughly with water. If the soil is to be compacted to the maximum dry density at the

optimum water content determined in accordance with light compaction or heavy compaction,

the exact mass of soil required is to be taken and the necessary quantity of water added so that

the water content of soil sample is equal to the determined optimum water content. The mould

with extension collar attached is clamped to the base plate. The spacer disc is inserted over the

base plate and a disc of coarse filter paper placed on the top of the spacer disc. The soil water

mixture is compacted into the mould in accordance with the methods specified in light

compaction test or heavy compaction test.

3.2.3 Step by Step processing of Methodology

1. The mould containing the specimen with the base plate in position but the top face

exposed is placed on the lower plate of the testing machine.

2. Surcharge weights, sufficient to produce an intensity of loading equal to the weight of

the base material and pavement is placed on the specimen.

3. To prevent upheaval of soil into the hole of the surcharge weights, 2.5 kg annular

weight is placed on the soil surface prior to seating the penetration plunger after which

the remainder of the surcharge weight is placed.

4. The plunger is to be seated under a load of 4 kg so that full contact is established

between the surface of the specimen and the plunger.

5. The stress and strain gauges are then set to zero. Load is applied to the penetration

plunger so that the penetration is approximately 1.25 mm per minute.

6. Readings of the load are taken at penetrations of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 4.0, 5.0,

7.5, 10.0 and 12.5 mm.

7. The plunger is then raised and the mould detached from the loading equipment.

3.2.4 Load- Penetration Curve

The load penetration curve is plotted taking penetration value on x-axis and Load values on

Y-axis. Corresponding to the penetration value at which the CBR is desired, corrected load

value is taken from the load-penetration curve and the CBR calculated as follows California

bearing ratio = (PT/PS) x100 Where PT = Corrected unit (or total) test load corresponding to

the chosen penetration curve, and PS = Unit (or total) standard load for the same depth of

penetration as for PS taken from standard code.The CBR values are usually calculated for

penetration of 2.5 mm and 5 mm. The CBR value is reported correct to the first decimal place.


Experimental Study


Figure 2 Preparation of Geotextile.

Figure 3 mixing of stone dust with BC soil.

Figure 4 BC soil with 15% of stone dust.

Figure 5 Testing of CBR with Geotextile.



4. RESULTS &DISCUSSION

Table 1 Compaction test of Soil Sample

s.no Description Trial 1 Trial 2 Trial 3 Trial 4

1 Weight of mould +wet soil(w2)(gm) 3610 3762 3860 3800

2 Weight of wet soil(w2-w1) (gm) 1690 1842 1940 1880

3 Empty mould no 1 2 3 4

4 Weight of empty container (gm) 33.14 33.30 32.66 29.05

5 Weight of container + wet soil 53.44 58.29 68.41 51.90

6 Weight of container + dry soil 51.92 56.01 64.20 48.83

7 Weight of water(5-6) gm 1.52 2.28 4.21 3.07

8 Weight of dry soil(6-4) gm 18.78 22.71 31.54 19.78

9 Water content =(7*100/8) % 8.09 10.03 13.34 15.52

10 Wet density =2/v in g/cc 1.69 1.84 1.94 1.88

11 Dry density=10/(1+w/100) in g/cc 1.56 1.67 1.71 1.62

Optimum moisture content = 12% Maximum dry density = 1.71 g/cc

Figure 6 Compaction graph for Moisture content (x-axis) v/s Dry density (y-axis).

Table 2 California bearing ratio of soil sample

S.no Penetration dial

reading

Penetration in

(mm)

Proving ring dial readings in

divisions Load in (kg)

1 0 0 0 0

2 50 0.5 5.1×5 =25.5 21.80

3 100 1 9.2×5 =46 39.32

4 150 1.5 10.8 ×5=54 46.16

5 200 2 11.3×5 =56.5 48.30

6 250 2.5 12×05 =60 51.29

7 300 3 13.2× 5=66 56.89

8 350 3.5 14.2× 5=71 61.20

9 400 4 14.9×5 =74.5 64.22

10 450 4.5 15.3×5 =76.5 65.94

11 500 5 16.2×5 =81 69.25

12 550 5.5 16.7×5 =83.5 71.39


Experimental Study


13 600 6 17.1×5 =85.5 73.10

14 650 6.5 17.6×5 =88 75.23

15 700 7 18.3×5 =91.5 78.23

16 750 7.5 19.4×5 =97 82.93

17 800 8 20.1×5 =100.5 85.92

18 850 8.5 20.9×5 =104.5 89.34

1}. CBR value of soil at 2.50 mm penetration = ( × 100) = 3.74

2}. CBR value of soil at 5 mm penetration = ( × 100)= 3.36.. CBR value of the given

soil is 3.74.

Table 3 Properties of BC soil mixed with stone dust

S.no Property Percentage replacement of stone dust

0 % 5% 10% 15%

1 Liquid limit 58 47 45 42

2 Plastic limit 29 32 30 35

3 Plasticity index 29 15 15 7

4 OMC (%) 15 15 14 12

5 MDD (KN/m3) 1.71 1.82 1.95 2.14

6 CBR (%) 3.74 4.80 5.67 6.08

Figure 7 Various proportions of stone dust used and their CBR value.

Table 4 Properties of BC soil mixed with Geo-textile at varying depths

Sl. no Property Geo textile at various depths from top

0 mm 10 mm 15 mm 20 mm

1 Liquid limit 58 58 58 58

2 Plastic limit 29 29 29 29

3 Plasticity index 29 29 29 29

4 OMC (%) 15 15 15 15

5 MDD (KN/m3) 1.71 1.71 1.71 1.71

6 CBR (%) 3.74 7.92 7.33 6.99



Figure 8 Variations in the CBR value by placing Geo textile sheet at various depths.

Figure 9 CBR moulds with only black cotton soil, stone dust with BC soil, and geo textile with BC

soil

Table 5 Comparison of BC soil when mixed with stone dut and Geotextile

Sl no. Increase of CBR values when BC soil added with stone dust and Geotextile

1 Black cotton

soil

BC soil

+5% stone

dust

BC soil +

10%of

stone dust

BC

soil+15%

of stone

dust

BC soil

with

Geotextile

at depth of

20 mm

BC soil

with

Geotextile

at depth of

15 mm

BC soil

with

Geotextile

at depth of

10 mm

2 3.74 4.80 5.67 6.09 6.99 7.33 7.92

Figure 10 Variations in CBR value by replacing it with stone dust in (5%, 10% and 15%) by dry

weight and by placing Geo textile sheet at (50mm, 100mm and 150mm) deep.


Experimental Study


5. CONCLUSION

These are the California bearing ratio test results obtained from tests conducted on black

cotton with replacement of quarry dust and placing geo textile sheet.

1. With the addition of 5% of quarry dust by weight the C.B.R. value for plain soil is

increased from 3.74% to 4.80%.





4. With the placement of a geo textile sheet at a depth of 150mm from the top of the soil

the C.B.R value for the plain soil increased from 3.74% to 6.99%.


the C.B.R value for the plain soil increased from 3.74% to 7.33%.


the C.B.R value for the plain soil increased from 3.74% to 7.92%

From the above discussion it is concluded that with the addition of 15%quarry dust for

black cotton soil the C.B.R value is increased by % and by placing the geo textile at a depth

of 50mm from the top of the soil surface the C.B.R value is increased by %.

Thus through this experimental comparison of increasing the bearing capacity of black

cotton soil using stone dust and geo textile sheet. We conclude stating that use of geo textile

greatly influences the bearing capacity of soil to required degree of extent.

REFERENCES

[1] Ahmet Demir1, et al.,(2013), An experimental study on behavior of geosynthetic

reinforced stone columns 2nd International Balkans Conference Of Civil

Engineering,BCCCE,23-25 May2013,Epoka University.

[2] Ali, K et..al (2010), Behaviour of reinforced stone columns in soft soils: an experimental

study IndianGeoTechnical conference 2010, Geotrends

[3] ChungsikYoo, A.M.ASCE (2010), Performance of Geosynthetic-Encased Stone Columns

in Embankment Construction: Numerical Investigation. A.M.ASCE1J. Geotech.

Geoenviron. Eng.20 10.136:1148-1160

[4] Gupta.R and A. Trivedi (2010), Behavior of model circular footings on silty soils with

cellular supports.

[5] HamedNiroumand, et al.(2011), Soil Improvement by Reinforced Stone Columns Based

on Experimental Work. EJGE VOL.16[2011],BUND,L

[6] Joel Gneil,AbdelemalekBouazza (2008), Improvement of soft soils using geogrid encased

stone columns.

[7] J.A Black, Sivakumar, et al.,(2007), Reinforced Stone Columns in Weak Deposits:

Laboratory Model Study

[8] KameshwarRao et al., (2012), Comparative study of experimental and theoretical load

carrying capacity of stone column with and without encasement of geosynthetics IJAET

ISSN:2231-1963

[9] Murugesan.S and Rajagopal.K (2009), Shear load tests on stone columns with and without

geosyntheticencasement. Geotextiles and Geomembranes 24(2012) 349-358 ASCE(20),

[10] S. Murugesan and K.Rajagopal (2007), Model tests on geosynthetic-encased stone

columns. ASCE9(1),30-35



[11] Mohammed Y. et.al., (2010), Improvement of soft clays by end bearing stone columns

encased with geogrids.

[12] Mereena K.P. et.al., (2009), Triaxial compression of clay reinforced with quarry dust fibre

column

[13] Nagaraju S. S. and Mhaiskar S. Y. (2009), Experiments on use of geotextiles and

geocomposits in paved roads, IGC-90, I/section, II/article 6, P.89-92.

[14] Natrajan T. K., Murthy A.V.S.R. and Jai Bhagwan (2008), Geotextile Reinforcement in

Soils, IGC-87, Banglore, Dec.87, Vol.1, P. 335 to P.338.

[15] Parab S. R., Chodankar D. S., Shirgaunkar R. M., Fernandes M., Parab A. B., Aldonkar S.

S., Savoikar P. P. Geotubes for Beach Erosion Control in Goa International Journal of

Earth Sciences and Engineering 1013, ISSN 0974-5904, Volume 04, No 06 SPL, October

2011, P. 1013-1016.

[16] Patel N.M.; Reinforcing with A Geotextile Layer And Covering Pad, First Indian

Geotechnical Conferance on Reinforced Soil and Geotextiles (2008), P. B-3 to P. B-7,

(2008).

[17] Purkayastha and Bhaumik(2008), Performance of geogrid and geotextile below

foundation on soft soil, IGC-1988, Allahabad, Dec-88, Vol.I, P. 199 – 204

[18] Raghvendra H. B. and Krishnaswamy N.R.; Triaxial Behavior of Soil Reinforced With

Geotextile, IGC-90, I/Section, II/Art-8, P.99 to P.103.,(2008)

[19] Rao G. V, Kate J.M. and Katti A. R. (2007), Interface friction behavior of geogrids by

pullout test, IGC-90, I / section, II/article-9, P. 105-108.

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