Using Empirical Correlations to Evaluate the Compression Index of Tehran Clay

Correlations between different parameters are used extensively in geotechnical engineering. Using correlations reduces the costs of testing and more speeds in determining the geotechnical properties of soils. Various relations have been proposed to evaluate geotechnical properties in different regions across the globe. Correlations facilitate the evaluation of geotechnical properties. The correlation between different parameters depends on the type of the soil and the experimental method. Considering the fact that these relations depend on local soil properties, using these relations for other regions is contingent upon a careful evaluation. This study evaluates the feasibility of using correlations presented by researchers in different years for Tehran clay. The evaluation uses different statistical criteria. The study shows the Bowles (1979) relation, correlating the soil compression index and the initial void ratio, is the best fit for Tehran clay among the studied correlations. In addition, the quality of the correlations can be evaluated for Tehran clay. Correlations between the soil compression index and initial void ratio often estimate the compression index with acceptable accuracy while correlations between the compression index and other geotechnical properties, such as the initial water content, plasticity index, shrinkage index, the liquid limit, and the soil density, are less accurate.