Skip to main content
SpringerLink
Log in

Investigation of Hydraulic Conductivity and Matric Suction in Sand–Bentonite–Coal Ash Mixes

  • Original Paper
  • Published:
Indian Geotechnical Journal Aims and scope Submit manuscript

Abstract

Compacted bentonite–sand/coal ash mixtures have been used nowadays as backfilling materials for nuclear waste disposal systems and as a landfill liner as they possess low permeability and good adsorption capacity, which proves to be beneficial in order to encapsulate waste from the surrounding environment. This paper deals with the evaluation of matric suction using pressure plate apparatus and filter paper technique on compacted sand–bentonite–coal ash mixtures. While the bentonite content was varied from 5, 10, 15, 20, 30, 40% in case of sand–bentonite mixes 5, 10, 15, 20% for coal ash–bentonite mixes, coal ash percentage was varied from 10, 20, 30, 50% for sand–bentonite–coal ash mixes at fixed bentonite contents of 10, 15 and 20%. Data was fitted using two models—Van Genuchten, Fredlund and Xing to obtain the soil water characteristic curve (SWCC) and to estimate the SWCC variables for different soil mixes. The air entry value (AEV) and residual suction (Ψr) values decreased as the effective grain size (D 10) of soil increased. A distinction in the values of the AEV and Ψr was observed using the Van Genuchten, Fredlund and Xing Models. The effect of varying bentonite content for sand–bentonite, coal ash–bentonite mixes and varying coal ash content in case of sand–bentonite–coal ash mixes was ascertained upon the SWCC modelling parameters viz. a, n, m. It was concluded that the parameter ‘a’ is directly related to the air entry value while ‘n’ and ‘m’ follow a reverse relationship as the ‘m’ parameter decreases with an increase in the bentonite content. It was concluded from the study that suction pressure is an important factor related to the performance evaluation of the bentonite enriched soils to serve as a barrier material as the soil tends to be in the unsaturated condition throughout the year. As per the chosen materials in this study, i.e. bentonite and coal ash, it can be witnessed that the addition of high percentages of bentonite and coal ash to the soil lead to higher suction pressures, which may prove to be detrimental to the stability of the landfills. Also, keeping in mind the statutory requirement of low hydraulic conductivity for use as a liner material, hydraulic conductivity of soil mixes was determined in both saturated and unsaturated state.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  1. Komine H, Ogata N (1994) Experimental study on swelling characteristics of compacted bentonite. Can Geotech J 31:478–490

    Article  Google Scholar 

  2. Lloret A, Villar MV, Alonso EE et al (2003) Mechanical behaviour of heavily compacted bentonite under high suction changes. Geotechnique 53:27–40

    Article  Google Scholar 

  3. Wang Q, Tang AM, Cui YJ et al (2012) Experimental study on the swelling behaviour of bentonite/claystone mixture. Eng Geol 124:59–66

    Article  Google Scholar 

  4. Stoicescu JT, Haug MD, Fredlund DG (1998) The soil water characteristics of sand–bentonite mixtures used for liners and covers. In: Proceedings of the 2nd international conference on unsaturated soils, vol 1. Beijing, pp 143–148

  5. Fredlund D, Rahardjo H (1993) Soil mechanics for unsaturated soils. Wiley, New York

    Book  Google Scholar 

  6. Fredlund DG (2000) The implementation of unsaturated soil mechanics into geotechnical engineering, The R.M. Hardy address. Can Geotech J 37(5):963–986

    Article  Google Scholar 

  7. Pedarla A, Acharya R, Bheemasetti T, Puppala AJ, Hoyos LR (2015) Influence of mineral montmorillonite on soil suction modeling parameters of natural expansive clay. Indian Geotech J. doi:10.1007/s40098-015-0175-1

    Google Scholar 

  8. Alonso EE, Gens A, Josa A (1990) A constitutive model for partially saturated soils. Geotechnique 40:405–430

    Article  Google Scholar 

  9. Delage P, Howat MD, Cui YJ (1998) The relationship between suction and swelling properties in a heavily compacted unsaturated clay. Eng Geol 50:31–48

    Article  Google Scholar 

  10. Tinjum JM, Benson CH, Blotz LR (1997) Soil-water characteristic curves for compacted clays. J Geotech Geoenv Eng 11:1060–1069

    Article  Google Scholar 

  11. Vanapalli SK, Pufahl DE, Fredlund DG (1999) The effect of soil structure and stress history on the soil-water characteristics of a compacted till. Geotechnique 49(2):143–159

    Article  Google Scholar 

  12. Fredlund DG (2002) Use of the soil-water characteristic curve in the implementation of unsaturated soil mechanics. In: Proceedings of the 3rd international conference on unsaturated soils. Taylor and Francis, Oxfordshire

  13. Fleureau JM, Verbrugge JC, Huergo PJ, Correia AT, Saoud SK (2002) Aspects of the behavior of compacted clayey soils on drying and wetting paths. Can Geotech J 39:1341–1357

    Article  Google Scholar 

  14. Yang H, Rahardjo H, Leong EC, Fredlund DG (2004) Factors affecting drying and wetting soil-water characteristic curves of sandy soils. Can Geotech J 41(5):908–920

    Article  Google Scholar 

  15. Vanapalli SK, Pufahl DE and Fredlund DG (1998) The effect of stress state on the soil-water characteristic behavior of a compacted sandy-clay till. In: Proceedings of the 51st Canadian geotechnical conference. Canadian Geotechnical Society, Montreal, pp 81–86

  16. Marinho FAM, Stuermer MM (1999) The influence of the compaction energy on the SWCC of a residual soil. In: Proceedings of the advances in unsaturated geotechnics. ASCE, Reston, VA, pp 125–141

  17. Marinho FAM (2005) Nature of soil-water characteristic curve for plastic soils. J Geotech Geoenviron Eng 131(5):654–661

    Article  Google Scholar 

  18. Van Genuchten M (1980) A closed form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:892–898

    Article  Google Scholar 

  19. Fredlund DG, Xing A (1994) Equations for the soil-water characteristic curve. Can Geotech J 31(4):521–532

    Article  Google Scholar 

  20. IS: 2720 (1985) Methods of test for soils-Grain size analysis, Part 4. Bureau of Indian Standards, New Delhi

  21. IS 1498: (1970) Indian Standard classification and identification of soils for general engineering purposes. Bureau of Indian Standards, New Delhi

  22. ASTM C 618-15 (2015) Standard specification for coal fly ash and raw or calcined natural pozzolana for use in concrete. American Society for Testing and Materials, West Conshohocken, PA

  23. Gleason MH, Daniel DE, Eykholt GR (1997) Calcium and sodium bentonite for hydraulic containment applications. J Geotech Geoenviron Eng ASCE 123(5):438–445

    Article  Google Scholar 

  24. Gueddouda MK, Goual I, Benabed B, Taibi S, Aboubekr N (2016) Hydraulic properties of dune sand–bentonite mixtures of insulation barriers for hazardous waste facilities. J Rock Mech Geotech Eng 8:541–550

    Article  Google Scholar 

  25. Hilf JW (1956) An investigation of pore water pressure in compacted cohesive soils. Technical Memo, 654, USBR, Denver, Colorado

  26. Oliveira OM, Marinho FAM (2008) Suction equilibration time for a high capacity tensiometer. Geotech Test J 31(1):1–5

    Google Scholar 

  27. Fredlund DG, Rahardjo H, Leong EC, Ng CWW (2001) Suggestions and recommendations for the interpretation of soil-water characteristic curves. In: Proceedings of the 14th Southeast Asian geotechnology conference Hong Kong, vol 1. pp 503–508

  28. Kenney TC, van Neen WA, Swallow MA, Sungaila MA (1992) Hydraulic conductivity of compacted bentonite-sand mixtures. Can Geotech J 29(3):364–374

    Article  Google Scholar 

  29. Mollins LH, Stewart DI, Cousens TW (1996) Predicting the properties of bentonite-sand mixtures. Clay Miner 31:243–252

    Article  Google Scholar 

  30. Fan RD, Du YJ, Reddy KR, Liu SY, Yang YL (2014) Compressibility and hydraulic conductivity of clayey soil mixed with calcium bentonite for slurry wall backfill: Initial assessment. Appl Clay Sci 101:119–127

    Article  Google Scholar 

  31. Zapata CE, Houston WN, Houston SL, Walsh KD (2000) Soil water characteristic curve variability. In: Shackleford CD, Houston SL, Chang N-Y (eds) Advances in unsaturated soil mechanics, geotechnical special publication 99. Geo-Institute of the ASCE, Reston, VA, pp 84–124

    Google Scholar 

  32. Hosseini SMMM, Ganjian N, Yadolah Pashang Pisheh YP (2011) Estimation of the water retention curve for unsaturated clay. Can J Soil Sci 91:543–549. doi:10.4141/CJSS10014

    Article  Google Scholar 

  33. Brooks RH, Corey AT (1964) Hydraulic properties of porous medium hydrology. Hydrology Paper, 3, Department of Civil Engineering, Colorado State University, Fort Collins, CO

  34. Indrawan IGB, Rahardjo H, Leong EC (2006) Effects of coarse grained materials on properties of residual soil. Eng Geology 82(3):154–164

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Civil Engineering, PEC University of Technology, Sector-12, Chandigarh, India

    Jaskiran Sobti & Sanjay Kumar Singh

Authors
  1. Jaskiran Sobti
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sanjay Kumar Singh
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Sanjay Kumar Singh.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sobti, J., Singh, S.K. Investigation of Hydraulic Conductivity and Matric Suction in Sand–Bentonite–Coal Ash Mixes. Indian Geotech J 47, 542–558 (2017). https://doi.org/10.1007/s40098-017-0282-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40098-017-0282-2

Keywords

Search

Navigation