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

The constant rate of strain (CRS) oedometer test, using an imposed vertical strain rate ε_I equal to 10 times the end-of-primary (EOP) vertical strain rate ε_p, requiring a test duration of about 2 days produces reliable information on both the e versus logσ_v^′ relation and e versus logk_v relation of soft clays and fibrous peats. An empirical correction for the strain rate effect on preconsolidation pressure leads to the EOP e versus logσ_v^′ relation and EOP σ_p^′ . The imposed vertical strain rate ε_I produces excess pore-water pressures at the impervious bottom of the specimen, corresponding to u_b^′ /σ_v 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.