Estimation of compressibility for normally consolidated clays using PCPT dissipation results

The piezocone penetration test (PCPT) is particularly effective for the characterization of saturated clays as it allows measurements of both strength and consolidation properties. While various PCPT-based methods have been developed, most of them have focused on time-dependent consolidation characteristics, and no specific attention has been given to the evaluation of compressibility-related parameters. In this paper, a methodology was proposed for the estimation of the compression index using PCPT dissipation results. In order to reflect stress state and volume change during consolidation, the time-stress-volume change relationship was analyzed and introduced into the investigation. Based on the concept of the coupled time-stress-volume relationship, a correlation was proposed between the compression index and PCPT dissipation results. PCPT and consolidation test results from 2 test sites near offshore areas were obtained and used to evaluate the correlation parameter for the proposed method. Calculated results using the proposed method showed reasonable agreement with measured results. Additional test sites from the literature were selected and adopted to verify the proposed method.