Estimation of consistency limits of fine-grained soils via regression analysis: A special case for high and very high plastic clayey soils in Istanbul

Consistency limits are essential and simple design parameters that are utilized as standard entries of all kinds of soil investigation programs conducted for geotechnical projects which are constructed in/on fine grained soils. These limits also represent mineralogical and physical properties of clayey soils directly and used to estimate their strength and rigidity properties indirectly. However, the consistency tests are assumed as the simple and basic tests of geotechnical engineering investigations, but the effects of operator, calibration of the device and environmental aspects at the tests damage the reliability and correctness of results. In this paper, it is aimed to overcome these challenges by evaluating the consistency characteristics of clayey soils considering only the values of liquid limit of specific clays with the use of simple regression analysis. A database is prepared by using 500 soil investigation reports that are involving the site characterization information, laboratory and field tests of Istanbul Province European side clayey soils, including Avcılar, Esenyurt, Küçükçekmece, Büyükçekmece, Çatalca, Zeytinburnu, Bahçelievler, Bakırköy districts. 1523 liquid limit tests are obtained from the mentioned database for high and very high plastic clays. The regression analyses have been applied to query the parameter effect ratio on the consistent characteristics and relationships have been tried to be developed to evaluate the values of plastic limit and plasticity index directly from only liquid limit test applications. The effects of fine material content, depth and natural water content is also investigated. Verifications of the suggested equations have been done for different cases and comparisons are made with the well-known sources of literature. Consequently, strong equations are acquired to determine the plasticity index value in terms of liquid limit, liquid limit-depth, liquid limit-fine content, natural water content-fine content respectively based on the actual experimental tests conducted in Istanbul.

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  • 1. Das, B.M. and K. Sobhan, Principles of Geotechnical Engineering. Eight Edition, Cengage Learning, USA, 2017.
  • 2. Atterberg, A., Über die physikalische Bodenuntersuchung, und über dile Plastizität de Tone, International Mitteilungen für Bodenkunde, 1, 10-43.
  • 3. Kollaros, G., Liquid limit values obtained by different testing methods. Bulletin of the Geological Society of Greece, 2016. 50(2): p.778-787.
  • 4. Casagrande, A., Research of Atterberg Limits of soils. Public Roads, 1932. 13(8): p.121–136.
  • 5. Casagrande, A., Notes on the design of the liquid limit device. Géotechnique, 1958. 8 (2): p.84–91.
  • 6. Skempton, A. W. and R.D. Northey, The sensitivity of clays. Geotechnique, 1953. 3: p.30-53.
  • 7. Fall, D., A Numerical model for repaid determination of plasticity of fine grained soils, Ground Engineering, 2000.
  • 8. Chenari, R. J., P. Tizpa, M.R.G. Rad, S.L. Machado and M.K. Fard, The use of index parameters to predict soil geotechnical properties, Arabian Journal of Geosciences, 2014. 8 (7): p.1-13.
  • 9. Tanzen, R., T. Sultana, M.S. Islam and A.J. Khan, Determination of plastic limit using cone penetrometer. Proceedings of 3rd International Conference on Advances in Civil Engineering, 2016. p. 209-214.
  • 10. Kuriakose, B., B.M. Abraham, A. Sridharan and B.T. Jose, Water content ratio: An effective substitute for liquidity index for prediction of shear strength of clays. Geotechnical and Geological Engineering, 2017. 35: p.1577-1586.
  • 11. Naveena, N., S.J. Sanjay and N.S. Chandanshree, Establishing relationship between Plasticity Index and Liquid Limit by Simple Linear Regression Analysis. International Journal for Research in Applied Science & Engineering Technology, 2018. 6 (6): p.1975-1978.
  • 12. Jasim, M. M., R.M. Al-Khaddar and A. Al-Rumaithi, Prediction of bearing capacity, angle of internal friction, cohesion, and plasticity index using ANN (Case Study of Baghdad, Iraq). International Journal of Civil Engineering and Technology, 2019. 10 (1): p.2670-2679.
  • 13. Cantillo, V., V. Mercado and C. Pàjaro, Empirical correlations for the swelling pressure of expansive clays in the city of Barranquilla, Colombia. Earth Sciences Research Journal, 2017. 21 (1): p. 45-49.
  • 14. Spagnoli, G. and M. Feinendegen, Relationship between measured plastic limit and plastic limit estimated from undrained shear strength, water content ratio and liquidity index. Cambridge University Press, 2017. 52 (4): p. 509-519.
  • 15. Shimobe, S., G. Spagnoli, Relationships between undrained shear strength, liquidity index, and water content ratio of clays. Bulletin of Engineering Geology and Environment, 2020.
  • 16. Barnes, G. E., A multi-linear approach to strength and plasticity states between the Atterberg limits. Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, 2020.
  • 17. Golawska, K., Z. Lechowicz, W. Matusiewicz and M.J. Sulewska, Determination of the Atterberg Limits of Eemian Gyttja on samples with different composition, Studia Geotechnica et Mechanica,2020. 42(2): p.168–178.
  • 18. Hussain, A. and C. Atalar, Estimation of compaction characteristics of soils using Atterberg limits, IOP Conference Series : Materials Science and Engineering, 2020. 800 (2020).
  • 19. Singh H. and A.K. Gupta, Correlation between shear strength of soils and water content ratio as a substitute for liquidity index. Advances in Computer Methods and Geomechanics, 2020. 56: p.299-306.
  • 20. Burmister, D. M., Principles and techniques of soil identification, Proceedings, Annual Highway Research Board Meeting. National Research Council, Washington, D.C., 1949. Vol. 29: p. 402–434.
  • 21. The districts of Istanbul [cited 2020 6 May]; Available from: https://istanbulharitasi360.com/istanbul-ilce-haritasi
  • 22. Seed, H. B., R.J. Woodward and R. Lundgren, Fundamental aspects of the Atterberg Limits, Journal of the Soil Mechanics and Foundations Division, 1964. 90 (6): p. 75-106.
  • 23. Nagaraj, T.S. and M.S. Jayadeva, Critical reappraisal of plasticity index of soils. J. Geotech. Eng. Div., ASCE, 1983. 109(7): p.994-1000.
  • 24. Spagnoli, G., A. Sridharan, P. Oreste, D. Bellato and L.D. Matteo, Statistical variability of the correlation plasticity index versus liquid limit for smectite and kaolinite. Applied Clay Science, 2018. 156 (2018): p.152-159.