RELATIONSHIP BETWEEN THE COMPRESSIBILITY PARAMETERS OF SOIL AND THE INDEX PROPERTIES A CASE STUDY OF UNWANA AFIKPO NORTH L.G.A. EBONYI STATE, NIGERIA

Abstract

Soil compressibility is a critical engineering consideration for soils. Granular soils derive their compressive stiffness from their density, i.e., the arrangement of individual particles. Samples collected from five (5) different locations of Unwana were subjected to laboratory experiments in accordance with relevant ASTM standards to determine the index and compressibility parameters.  Correlations have been established in the form of exponential fit based on simple regression analysis to assess the plasticity index PI as a function of coefficient of volume change (MV), coefficient of volume compressibility (AV), Rate of compressibility index (CV) and coefficient of compressibility index (Cc) respectively.  From the experimental study, it was observed that the soils exhibited a wide range of plasticity index from 16.0 to 40.7%.  The values of coefficient of determination (R²) for the equations lie within the range of 0.79 to 0.99 and errors in the predicted values of MV, AV, Cv and Cc as a function of PI are within the range of +0.06 to +10 x 10^-9% which show the efficiency of the relationship.  Percentages of errors in the predicted values are very close (±10%), so the equations may be successfully implemented in the field.