Assessing the Reliability of Empirical Correlations for Compression Index Prediction in Fine-Grained Soils

Abstract

Settlement can cause significant damage to buildings and infrastructure constructed on highly compressible soils. The compression index (Cc) is a key parameter in estimating the magnitude of potential settlement. Empirical equations are commonly used to efficiently obtain Cc values, providing a practical alternative to time-consuming 1D oedometer testing. However, inaccurate Cc estimations can adversely affect design decisions, construction techniques, and subsequent repair strategies. This study compared Cc values derived from 1D oedometer tests with those calculated using empirical equations. Additionally, the suitability of seven empirical equations was assessed for soils in the Cikarang and Marunda regions. Analysis of 36 undisturbed samples revealed that each empirical equation produced varying results, indicating that physical parameters alone are insufficient for predicting soil compressibility. The findings suggest that, for the soils studied, Bowles' (1981) empirical equation with a correction factor of 0.491 yields the most accurate Cc estimates.