Evaluation of secondary compressibility of a soft clay

Abstract

It is widely accepted that the influence of sustained loading on the rate of secondary compression for all natural soil deposits resembles the effect of preloading. The magnitude of settlement during secondary compression increases with increasing duration of loading. As a result, after longer periods of secondary consolidation, clay samples can sustain relatively larger stress increments before volume changes begin to occur, and display less settlement during next loading stage. The influence of sustained loading has been investigated in this study by long-term consolidation tests. Based on experimental data it has been shown that there is a fairly well defined dependence of $C_alpha$ on effective stress. Furthermore, the relations between secondary compression parameters and consolidation pressure have also been examined and a correlation between secondary compression index and consolidation pressure has been introduced and discussed in the paper.