Soil Water Characteristic Curve of a Compacted A-7-5 Tropical Red Earth Soil


  • J. O. Okovido Department of Civil Engineering, University of Benin, Benin City, Edo State, NIGERIA
  • E. O. Obroku Department of Civil Engineering, Igbinedion University, Okada, Edo State, NIGERIA


tropical red earth soil, SWCC, matric suction, filter paper


Soil water characteristic curve (SWCC) is a very important property of unsaturated soil and by extension tropical red earth soils. This is because several other important soils’ properties can be related to it. The Filter paper method was employed in the determination of the A-7-5(5) tropical red earth WCC. The gravimetric water content was utilized in the computation of the SWCC. Four models, Fredlund and Xing (1994), FX; Van Genuchten (1980), VG; Brooks and Corey (1964), BC; and Kosugi (1996), K were used to estimate the SWCCs of the soil and the minimum SSEnorm (MSSE), Average Relative Error (ARE), and R^2 values were used to determine the most suitable model for predicting the SWCC. Results show that all four models can be used to predict A-7-5(5) WCC as they all had R^2 value greater than 89% although BC and K models perform best with coefficient of determination of over 97%. MSSE and ARE% were also significantly low for BC and K models.






Building, Civil & Geotechnical Engineering