Constant rate of strain consolidation testing of soft clays and fibrous peats

Abstract

The constant rate of strain (CRS) oedometer test, using an imposed vertical strain rate [Formula: see text] equal to 10 times the end-of-primary (EOP) vertical strain rate [Formula: see text], requiring a test duration of about 2 days produces reliable information on both the e versus log[Formula: see text] relation and e versus logkv relation of soft clays and fibrous peats. An empirical correction for the strain rate effect on preconsolidation pressure leads to the EOP e versus log[Formula: see text] relation and EOP [Formula: see text]. The imposed vertical strain rate [Formula: see text] produces excess pore-water pressures at the impervious bottom of the specimen, corresponding to [Formula: see text] values in the range of 3%–15% and allows, use of the Darcy flow equation, a reliable calculation of the coefficient of permeability. Compressibility and permeability data are from CRS and incremental loading (IL) oedometer tests on specimen quality designation (SQD) A samples of seven soft clays and two fibrous peats are presented in this paper.