Shrink–Swell Potential of Lateritic Soils in Ibadan Metropolis
Downloads
Volumetric instability of lateritic subgrade soils can adversely affect pavement performance in tropical environments where seasonal wetting and drying are pronounced. This study evaluated the shrink–swell potential of lateritic soils across the eleven Local Government Areas (LGAs) of Ibadan Metropolis, Southwestern Nigeria, with emphasis on the role of the silty–clay/fines fraction. Thirty-three samples, representing three sampling locations per LGA, were obtained from the shallow active subgrade zone at depths of approximately Atterberg limits, Linear Shrinkage (LS) and Free Swell Index (FSI) tests. The percentage passing the 0.075 mm sieve (P₀.₀₇₅) ranged from 20.8% to 39.5%, Liquid Limit from 28.1% to 48.5%, Plasticity Index from 10.6% to 23.3%, and specific gravity from 2.58 to 2.76. Linear Shrinkage ranged from 5.74% to 16.13%, while FSI ranged from 14.1% to 36.3%. Strong positive relationships were obtained between P₀.₀₇₅ and FSI (r = 0.915), P₀.₀₇₅ and LS (r = 0.781), and PI and FSI (r = 0.982). The PI–FSI regression, (FSI = 1.68PI) placed most samples in AASHTO A-2-6 and USCS SC, while Ido and Oluyole contained the A-7-6/SC soils with the highest fines and volumetric responses. Three broad Shrink–swell hazard zones were identified: low Shrink–swell hazard in Ona-Ara and Egbeda, moderate Shrink–swell hazard in Akinyele, Lagelu and the five urban-core LGAs, and high hazard in Ido and Oluyole. Only four of the 33 samples (12.1%) satisfied the adopted 8% Linear Shrinkage criterion. The findings support location-specific subgrade investigation, moisture control, drainage and stabilisation rather than a uniform treatment strategy across Ibadan.
Adeyemi, G. O. (1995). The influence of parent rock factor on some engineering index properties of three residual lateritic soils in southwestern Nigeria. *Bulletin of the International Association of Engineering Geology, 52*(1), 3–8.
Adeyemi, G. O., & Anifowose, A. Y. B. (2005). Engineering geological evaluation of lateritic soils in Ibadan area, southwestern Nigeria. *Journal of Mining and Geology, 41*(2), 111–118.
Adeniyi, O. B. (2025). Geotechnical characterisation of lateritic soils at Federal University Oye-Ekiti, Ikole Campus: Implications for foundation design. *NAU Journal of Civil Engineering*.
Akinola, O. O., & Adeyemi, G. O. (2017). Assessment of swelling potential of some lateritic soils in Ibadan, southwestern Nigeria. *Nigerian Journal of Technological Development, 14*(2), 35–42. American Society for Testing and Materials. (2017). *Standard test methods for liquid limit, plastic limit, and plasticity index of soils (ASTM D4318).* ASTM International.
Badmus, B. S. (2022). Plasticity and compressibility characteristics of lateritic soil from southwestern Nigeria. *Journal of Natural Sciences, Engineering and Technology, 9*(1), 1–15. British Standards Institution. (1990). *Methods of test for soils for civil engineering purposes (BS 1377).* BSI.
Chen, F. H. (1988). *Foundations on expansive soils.* Elsevier.
Gidigasu, M. D. (1976). *Laterite soil engineering: Pedogenesis and engineering principles.* Elsevier Scientific Publishing Company.
Holtz, W. G., & Gibbs, H. J. (1956). Engineering properties of expansive clays. *Transactions of the American Society of Civil Engineers, 121*(1), 641–663.
Nelson, J. D., & Miller, D. J. (1992). *Expansive soils: Problems and practice in foundation and pavement engineering.* Wiley.
Ogunribido, T. H. T. (2018). Geotechnical properties of some lateritic soils in southwestern Nigeria and their implications for road construction. *Journal of Geology and Mining Research, 4*(1), 1–6.
Ola, S. A. (1983). Geotechnical properties and behaviour of some Nigerian lateritic soils. In *Proceedings of the First National Conference on Geotechnical Engineering* (pp. 1–34).
Owoseni, J. O., & Olofinyo, O. O. (2021). Sustainable improvement of residual lateritic soils using alum. *Journal of Scientific and Technological Research*.
Seed, H. B., Woodward, R. J., & Lundgren, R. (1962). Prediction of swelling potential for compacted clays. *Journal of the Soil Mechanics and Foundations Division, ASCE, 88*(SM3), 53–87.
Skempton, A. W. (1953). The colloidal activity of clays. *Proceedings of the 3rd International Conference on Soil Mechanics and Foundation Engineering, 1*, 57–61.
Umar, M., & Ibrahim, S. M. (2020). Evaluation of expansive behaviour of lateritic soils in parts of southwestern Nigeria. *Nigerian Journal of Geotechnical Engineering, 6*(1), 15–25.
