ESTIMATION OF BEARING CAPACITY OF BLACK COTTON SOIL USING ROCK DUST AND GEO-TEXTILE SHEET: AN EXPERIMENTAL STUDY

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 10, October 2017, pp , Article ID: IJMET_08_10_096 Available online at ISSN Print: and ISSN Online: 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 editor@iaeme.com

2 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 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 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 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 editor@iaeme.com

3 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 stone dust at Railapur village 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. 3.2 Process of the methodology Figure Geotextile 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 editor@iaeme.com

4 N. Vijay Kumar, SS.Asadi and A.V.S. Prasad 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 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 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 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 = (P T /P S ) x100 Where P T = Corrected unit (or total) test load corresponding to the chosen penetration curve, and P S = Unit (or total) standard load for the same depth of penetration as for P S 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 editor@iaeme.com

5 Estimation of Bearing Capacity of Black Cotton Soil Using Rock Dust and Geo-Textile Sheet: An 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 editor@iaeme.com

6 N. Vijay Kumar, SS.Asadi and A.V.S. Prasad 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) Weight of wet soil(w2-w1) (gm) Empty mould no Weight of empty container (gm) Weight of container + wet soil Weight of container + dry soil Weight of water(5-6) gm Weight of dry soil(6-4) gm Water content =(7*100/8) % Wet density =2/v in g/cc Dry density=10/(1+w/100) in g/cc Optimum moisture content = 12% Maximum dry density = 1.71 g/cc S.no Figure 6 Compaction graph for Moisture content (x-axis) v/s Dry density (y-axis). Penetration dial reading Table 2 California bearing ratio of soil sample Penetration in (mm) Proving ring dial readings in divisions Load in (kg) = = = = = = = = = = = editor@iaeme.com

7 Estimation of Bearing Capacity of Black Cotton Soil Using Rock Dust and Geo-Textile Sheet: An Experimental Study = = = = = = S.no 1}. CBR value of soil at 2.50 mm penetration = ( 100) = }. CBR value of soil at 5 mm penetration = ( 100)= CBR value of the given soil is Property Table 3 Properties of BC soil mixed with stone dust Percentage replacement of stone dust 0 % 5% 10% 15% 1 Liquid limit Plastic limit Plasticity index OMC (%) MDD (KN/m 3 ) CBR (%) Sl. no 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 Property Geo textile at various depths from top 0 mm 10 mm 15 mm 20 mm 1 Liquid limit Plastic limit Plasticity index OMC (%) MDD (KN/m 3 ) CBR (%) editor@iaeme.com

8 N. Vijay Kumar, SS.Asadi and A.V.S. Prasad 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 6.99 BC soil with Geotextile at depth of 15 mm 7.33 BC soil with Geotextile at depth of 10 mm 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 editor@iaeme.com

9 Estimation of Bearing Capacity of Black Cotton Soil Using Rock Dust and Geo-Textile Sheet: An 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%. 2. With the addition of 10% of quarry dust by weight the C.B.R. value for plain soil is increased from 3.74% to 5.67%. 3. With the addition of 15% of quarry dust by weight the C.B.R. value for plain soil is increased from 3.74% to 6.08%. 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%. 5. With the placement of a geo textile sheet at a depth of 100mm from the top of the soil the C.B.R value for the plain soil increased from 3.74% to 7.33%. 6. With the placement of a geo textile sheet at a depth of 50mm from the top of the soil 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 : [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: [9] Murugesan.S and Rajagopal.K (2009), Shear load tests on stone columns with and without geosyntheticencasement. Geotextiles and Geomembranes 24(2012) ASCE(20), [10] S. Murugesan and K.Rajagopal (2007), Model tests on geosynthetic-encased stone columns. ASCE9(1), editor@iaeme.com

10 N. Vijay Kumar, SS.Asadi and A.V.S. Prasad [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 [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 , Volume 04, No 06 SPL, October 2011, P [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 [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 editor@iaeme.com