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Geotechnical Characterization and WRCC for Spatially Varied Pond Ash within an Ash Pond

  • Janmeet Singh
  • Sanjay Kumar Singh
Original Paper
  • 8 Downloads

Abstract

Thermal power plants produce a large quantity of coal ash as a by-product from the combustion of pulverized coal. A small quantity of total coal ash produced is currently being utilized, whereas unutilized coal ash is deposited in vicinity of thermal power plant as waste material which covers several hectares of useful land. The utility of coal ash in various applications related to geotechnical and geoenvironmental field has been increased manifold. In most of these applications, thorough understanding of geotechnical characteristics and water retention characteristics curve of pond ash is required. There are not many studies that deal with study of effect of spatial distribution of pond ash within the ash pond on the geotechnical characterization and soil water characteristic behavior of ash. This paper presents the results of geotechnical characterization and water retention characteristics curves of pond ash which were collected from different locations from inflow to outflow of Ropar thermal power plant (India). Index properties and engineering properties (permeability, strength parameters) of ash changed significantly upon the spatial variation from inlet of slurry point to outflow of decanted water. Classification of ash changed from SM to ML as it is moved away from inlet to outflow point. Distinctly different drying and wetting curves were observed for ash samples collected from inflow to outflow points. Results revealed that inflow points exhibited higher specific gravity, low air entry value as compared to outflow points. Further, investigation was carried out to study WRCC hysteresis of samples collected from inflow to outflow in an ash pond. It is concluded from the results that coarse ash sample exhibits lesser degree of WRCC hysteresis. The results presented in this paper signify the importance of considering WRCC hysteresis for a pond ash samples spatially distributed in an ash pond. The results obtained for pond ash was also compared with the natural sand in order to make a comparison with natural sand for its possible replacement in place of sand in various civil engineering applications.

Keywords

Pond ash Water retention characteristic curve Hysteresis 

References

  1. 1.
    Central Electricity Authority (2015) Fly ash generation at coal/lignite based thermal power stations and its utilization in the country. New Delhi, IndiaGoogle Scholar
  2. 2.
    Fredlund DG, Rahardjo H (1993) Soil mechanics for unsaturated soils. Wiley, New YorkCrossRefGoogle Scholar
  3. 3.
    Rahardjo H, Lim TT, Chang MF et al. (1995) Shear strength and in situ matric suction of a residual soil. In: Proceedings of Unsaturated SoilsGoogle Scholar
  4. 4.
    Sreedeep S, Singh DN (2003) Laboratory measurement of soil suction. Indian Geotech J 33(3):279–290Google Scholar
  5. 5.
    Sreedeep S (2006) Modeling contaminant transport in unsaturated soils. Ph.D. Thesis, Department of Civil Engineering, Indian Institute of Technology Bombay, IndiaGoogle Scholar
  6. 6.
    Fredlund DG (1996) Microcomputer and saturated/unsaturated continuum modelling in geotechnical engineering. Symp Comput Geotech Eng, Brazil 2:29–50Google Scholar
  7. 7.
    Power K., Vanapalli SK (2008) Influence of matric suction on the compressibility behaviour of a compacted unsaturated fine-grained soil. In: Proceedings of Canadian Geotechnical Conference, OttawaGoogle Scholar
  8. 8.
    Dane JH, Wierenga PJ (1975) Effect of hysteresis on the prediction of infiltration, redistribution and drainage of water in a layered soil. J Hydrol 25:229–242CrossRefGoogle Scholar
  9. 9.
    Topp GC, Miller EE (1966) Hysteretic moisture characteristics and hydraulic conductivities for glass-bead media. Soil Sci Soc Am J 30(2):156–162CrossRefGoogle Scholar
  10. 10.
    Likos WJ, Lu N, Godt JW (2014) Hysteresis and uncertainty in soil water-retention curve parameters. J Geotech Geoenviron Eng 140(4):040130501–040130511CrossRefGoogle Scholar
  11. 11.
    Zeng ZT, Lu HB, Zhao YL (2012) Wetting-drying effect of expansive soils and its influence on slope stability. Appl Mech Mater 170:889–893CrossRefGoogle Scholar
  12. 12.
    Brooks RH, Corey AT (1964) Hydraulic properties of porous media. Colorado State Univ Hydrol Papers, Fort Collins, Colorado 3:1–27Google Scholar
  13. 13.
    Ridley AM, Wray WK (1996) Suction measurement: a review of current theory and practices. Proc First Int Conf Unsaturated Soils 3:293–322Google Scholar
  14. 14.
    Agus S, Schanz T (2005) Comparison of four methods for measuring total suction. Vadose Zone J 4(4):1087–1095CrossRefGoogle Scholar
  15. 15.
    Sreedeep S, Singh DN (2011) A critical review of the methodologies employed for soil suction measurement. Int J Geomech 11(2):99–104CrossRefGoogle Scholar
  16. 16.
    IS 2720 Part 3 (1980) Methods of test for soils—determination of Specific Gravity. Bureau of Indian Standards, New DelhiGoogle Scholar
  17. 17.
    Pandian NS, Rajasekhar C, Sridharan A (1998) Studies of the specific gravity of some Indian coal ashes. J Test Eval 26(3):177–186CrossRefGoogle Scholar
  18. 18.
    IS 2720 Part 4 (1985) Methods of test for soils—grain size analysis. Bureau of Indian Standards, New DelhiGoogle Scholar
  19. 19.
    IS 2720 Part 7 (1980) Methods of test for soils—determination of water content-dry density drelation using light compaction. Bureau of Indian Standards, New DelhiGoogle Scholar
  20. 20.
    IS 2720 Part 17 (1986) Laboratory determination of permeability. Bureau of Indian Standards, New DelhiGoogle Scholar
  21. 21.
    Jakka RS, Ramana GV, Datta M (2010) Shear strength characteristics of loose and compacted pond ash. Geotech Geol Eng 28:763–778CrossRefGoogle Scholar
  22. 22.
    Jakka RS, Datta M, Ramana GV (2010) Liquefaction behavior of loose and compacted pond ash. Soil Dyn Earthq Eng 30(7):580–590CrossRefGoogle Scholar
  23. 23.
    Sobti J, Singh SK (2017) Hydraulic conductivity and compressibility characteristics of bentonite enriched soils as a barrier material for landfill. Innov Infrastruct Solut 2(12):1–13Google Scholar
  24. 24.
    Sobti J, Singh SK (2017) Investigation of hydraulic conductivity and matric suction in sand–bentonite–coal ash mixes. Indian Geotech J 47(4):542–558CrossRefGoogle Scholar
  25. 25.
    IS 1917 Part 1 (1991) Chemical analysis of quartzite and high silica sand—determination of loss on ignition. Bureau of Indian Standards, New DelhiGoogle Scholar
  26. 26.
    Aubertin M, Mbonimpa M, Bussiere B et al (2003) A model to predict the water retention curve from basic geotechnical properties. Can Geotech J 40(6):1104–1122CrossRefGoogle Scholar
  27. 27.
    Yang H, Rahardjo H, Leong EC et al (2004) Factors affecting drying and wetting soil water characterstic curves of sandy soils. Can Geotech J 41(5):908–920CrossRefGoogle Scholar
  28. 28.
    Scott HD (2000) Soil physics: agricultural and environmental applications. Iowa State University Press, Iowa StateGoogle Scholar

Copyright information

© Indian Geotechnical Society 2018

Authors and Affiliations

  1. 1.Punjab Engineering College (Deemed to be University)ChandigarhIndia

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