Optimization of Cost and Fibre Quantity in Stabilization of Soil

Optimization of Cost and Fibre Quantity in Stabilization of Soil

Prasad Gajanan Sonar

PG Scholar, Department of Civil Engineering,

TSSMs PVPIT,

SPPU Pune, India

Prof. P. R. Minde

Assistant Professor Department of Civil Engineering,

TSSMs PVPIT,

SPPU Pune, India

Abstract Once there is a change in a place, type of soil also get changes. Along with soil type the properties of soil also changes. For any kind out of construction we require stable foundation in the form of firm strata. This can be available naturally if hard rock encountered below the soil. But this condition can not be possible at every site. Hence stability of foundation soil is the major work in front of construction industry. Research shows lot of interest and many methods were found out for the stabilization of soil. Soil Stabilization by using cement and lime was the most ancient method which was commonly adopted all over the world. But it is found out that this will prove costly and time consuming. In this study the effect of inclusion of various types of fibres on unconfined compressive strength of clayey soil was studied. The fibres used were natural fibre, plastic fibre, polypropylene with different fibre contents and length. The fibre percentages were varied from 0% to 2%. The fibre length and fibre content are found to play important roles in the strength of fibre reinforced soil. Furthermore, it was observed that the unconfined compressive strength of soil sample taken for study increased by inclusion of fibres. Conclusions were obtained from this investigation that the inclusion of randomly distributed fibres significantly improved the unconfined compressive strength of clayey soil. Increase in fibre content decreases MDD and increases OMC. Optimum percentage of fibres was identified from the carried out study. Use of optimum quantity of fibre will reduce the cost of project. Results shows that soil stabilization by fibres will effects on the life cycle of the project ultimately project deration reduces.

Keywords Soils; Unconfined Compressive Strength; Optimum fibre quantity; Cost optimization.

1. INTRODUCTION

   Soils and their related behaviour has always been the subject of many studies. Recent researches show some interests in investigation of inclusion of randomly distributed fibre in soil. This study focuses on effect of fibre inclusion on the strength and other parameters of clayey sand composite material. This study is related to effective parameters on strength of the clayey sand composite with using natural fibre, plastic fibre, polypropylene, polyester with different fibre contents and length. UCS test were carried out to investigate behaviour of the composite under different condition. The fibre percentage varied from 0% (for unreinforced samples) to 2%.

   The aim of the present work is to study the effect of fibres in stabilization of soil and to optimize the required percentage of fibre at which soil sub-grade can give maximum unconfined compressive strength at least cost.

   Objectives of the study:

   • To study the influence of types of fibre on unconfined compressive strength.

   • To find the optimum percentage of fibre at which maximum unconfined compressive strength can be obtained.

   • To check the suitable type of fibre for stabilization of clayey soil.

   • To minimise the cost of soil stabilisation by using optimum quantity of fibre.

2. LITERATURE REVIEW

   1. T. Subramani, D. Udayakumar, (May 2016), Experimental Study on Stabilization of Clay Soil Using Coir Fibre

      The authors found that 0.5% coir fibre proportion in a soil is optimum percentage for maximum soaked California Bearing Ratio (CBR) value. They concluded that this proportion may be economically used in stabilization of clay soil.

   2. Parag M. Chaple, A I. Dhatrak, (May 2013), Performance of Coir fibre Reinforced Clayey Soil

      In this study coir were used in varying percentage as 0.25%, 0.5%, 0.75% & 1.0% and effect of coir on bearing capacity were determined. Provision of coir reinforced layer increases bearing capacity ratio up to 1.5 to 2.66.

3. MATERIAL USED

   1. Soil

      Local soil was collected from nearby place of Dr. BATU campus, Lonere. After conducting the tests on collected soil sample the soil was classified as clayey soil of low plasticity which was coarse and inorganic in nature (ML). The index properties of soil were determined as per Indian Standard test procedure (IS: 2720 Part 5 1970 and IS: 2720 Part 3 Sect 2 1981). The following table represents the physical properties of soil:

      S.N.	Test Properties	Result
      1.	Specific gravity	2.411
      2.	Natural Water Content (%)	27.50
      3.	Sieve Analysis % of Gravel % of Sand % of Fines	10.577 84.153 5.27
      4.	Cc Coefficient of Curvature	1.28
      5.	Cu (Uniformity Coefficient )	10.52
      6.	Optimum moisture content (%)	13
      7.	Maximum dry density (g/cc)	1.89
      8.	Unconfined Compressive Strength (kg/cm²)	1.7071

      Table 1. Engineering and Geotechnical properties of soil

      Disposal of hairs is the major task in front of environmentalist as it has a non-biodegradable nature and solution over this is to use it for soil stabilization. The properties of these fibers are given in table:

      Table 3: Properties of human hairs

      S.N.	Property	Remark
      1.	Cross-Section	Circular
      2.	Diameter	10-100 m
      3.	Length	5-50 mm
      4.	Elongation	1.5 times its dry weight
      5.	Tensile strength	Equal to Copper wire

   2. Coir

      Image 1: Coir coated with black oil paint

4. TESTING METHODOLOGY

   Index properties were first determined of soil sample to know the soil classification. Then to determine the proctor maximum dry density and optimum moisture content Modified proctor compaction test were carried out. Later on UCS test were carried out as per the procedures and guidelines laid down in Indian Standards Codes of practice. Four different types of fibres were used and each fibre type with different percentage (0.5%, 1%, and 2% of the total dry weight of the soil) was mixed with soil for each specimen.

5. RESULTS AND DISCUSSION

   This work consists of 3 types of fibres and one type of soil.

   Coir industry is one of the oldest industries in India, and coir has been traditionally used for packaging. However, its versatility is coming to light after the world had started looking for natural options to save the environment. Coir fibre is a coarser in nature. Coir fibre used for the study was purchased from local market. The diameter of the individual fibre varied between 2 mm to 10 mm. These fibers are generally available in the threaded form. Table 2 represents the basic prperties of coir used in this study.

   Table 2: Basic Properties of Coir

   Color	Yellowish brown
   Specific Gravity	1.12
   Diameter Used	2-8
   Ash (%)	0.5-1.04
   Wax (%)	0.4-0.81
   Nitrogen (%)	0.4
   Density	1825 kg/m3

   1. Human Hairs

      Image 2: Human Hairs

      From each fibre 9 samples were prepared by varying proportion and later on they were tested for unconfined compressive strength.

      Image 3: Original Sample Specimen

      Image 4: Sample by mixing of 1% Coir (without coated)

      The values of each sample were tabulated below:

      Table 4: Test results

      S.N.	Sample Notation	Type of Sample	UCS values (kg/cm2)
      1	B	Natural Soil	1.7071
      2	0.5H1	0.5% Hair mixed	2.4011
      3	1H3	1% Hair mixed	3.8711
      4	2H3	2% Hair mixed	3.5889
      5	0.5NC3	0.5% Natural Coir	1.3548
      6	1NC2	1% Natural Coir	1.8257
      7	2NC2	2% Natural Coir	4.8909
      8	0.5CC3	0.5% Coated Coir	1.3001
      9	1CC2	1% Coated Coir	2.2121
      10	2CC1	2% Coated Coir	2.747
      11	0.5P3	0.5% Plastic fibre	2.3203
      12	1P1	1% Plastic fibre	0.9303
      13	2P	2% Plastic fibre	0.7899

6. COST BENEFIT ANALYSIS

   As per IS 2720 Part X the required UCS value for black cotton soil was 2.69 Kg/cm2. Therefore the optimum percentage of fibre was so selected that which has UCS value nearer to the value specified by IS 2720 Part X. Initially the normal soil sample (without addition of any type of fibre) has 1.7071 kg/m2 UCS value which is less than the specified value of IS 2720 Part X. Hence there is necessity to add some percentage of fibre to increase UCS value. It was found that 1% addition of hairs will increase the UCS value up to 3.8711 kg/m2 and 2% addition of natural coir will increase the UCS value up to 3.6 kg/m2. Again,2% addition of Oil paint coated coir will increase the UCS value up to 2.747 kg/m2, 0.5% addition of Plastic fibre will increase the UCS value up to 2.3203 kg/m2 which is less than the required UCS value specified by IS 2720 Part X.

7. CONCLUSION

1. Addition of 0.5% of uncoated and coated coir resulted in decrease in Unconfined Compressive Strength (UCS) compared to normal soil. This is due to insufficient bond of coir with soil and less quantity of coir available for sufficient anchorage.

2. Addition of 2% coir has shown maximum UCS.

3. The UCS increased at 1% of coated coir fibre compared to addition of same quantity of uncoated fibre.

4. Due to smooth surface of plastic fibres the bond between fibres and soil was poor which resulted in early failure of samples.

ACKNOWLEDGMENT

The auther of this paper is highly obliged to the Department of Civil Engineering, Padmabhushan Vasantadada Patil Institute of Technology, Bavdhan, Pune and the Management of TSSM . Authors are thankful to Principal , Head of the Department and the other staff of the Institute. Auther would like to expess their deep sence of gratitude towards Department of Civil Engineering, Dr. Babasaheb Ambedkar Technological University, Lonere

REFERENCES

1. T. Subramani, D. Udayakumar, (May 2016), Experimental Study on Stabilization of Clay Soil Using Coir Fibre, International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, Volume 5, Issue 5, May 2016 | ISSN 2319 484.

2. Parag M. Chaple, A I. Dhatrak, (May 2013), Performance of Coir fibre Reinforced Clayey Soil. The International Journal of Engineering And Science (IJES), Volume 2, Issue 4, Pages 54-64, 2013. ISSN(e): 2319 – 1813 ISSN (p): 2319 1805, www.theijes.com, The IJES Page 54.

3. Stuti Maurya, Dr. A. K. Sharma, Dr. P. K .Jain, Dr. Rakesh Kumar, (June 2015), Review on Stabilization of Soil Using Coir Fibre, International Journal of Engineering Research ,ISSN:2319- 6890)(online),2347-5013(print), Volume No.4, Issue No.6, pp : 296-299, 01 June 2015

4. Phani Kumar. V,CH. Naga Bharath, P. Swathi Priyadarsini (Jan 2015), Experimental Investigation on California Bearing Ratio (CBR) For Stabilizing Silty Sand with Fly Ash and Waste Polypropylene,ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 4, Issue 7,

   January 2015

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6. IS: 1498 (1970), Indian Standard Methods of Test for Soils: Classification and Identification of Soil for General Engineering Purposes (Bureau of Indian Standards. 1970).

7. IS 2720: (Part II to Part XVI): Indian Standard Methods of test for soils, determination of properties of soil.