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Acta Geotechnica

, Volume 13, Issue 2, pp 399–417 | Cite as

Creep behaviour of intact and remoulded fibrous peat

  • Mohan P. Acharya
  • Michael T. Hendry
  • C. Derek Martin
Research Paper
  • 283 Downloads

Abstract

This paper presents the creep behaviour of intact and remoulded specimens of fibrous peat obtained from a field site near Anzac, Alberta, Canada. The creep behaviour was investigated by means of long-term drained and undrained triaxial tests. The development of volumetric, axial, and undrained axial strain and strain rate during drained and undrained creep tests under variable stress conditions is presented. The stress strain strain rate (p′ε v\(\dot{\varepsilon }_{\text{v}}\)) relationship is found to be unique for different stress and loading durations. The p′ε v\(\dot{\varepsilon }_{\text{v}}\) relationship is analysed and represented by creep isotaches. The applicability of different creep models developed for normally consolidated clay is discussed and applied to define the development of creep strain in fibrous peat under varying isotropic and deviator stresses. The secondary consolidation coefficient for evaluating the volumetric strain rate of peat is found to be applicable with some limits. The drained creep behaviour of remoulded peat specimens differs from the behaviour shown by Shelby tube specimens, whereas the undrained creep behaviour in remoulded and Shelby tube specimens is similar.

Keywords

Creep test Fibrous peat Strain and strain rate Stress Triaxial test 

List of symbol

Cc

Coefficient of compression

Cα

Coefficient of secondary compression

1D

One-dimensional compression

p0

Preconsolidation pressure

p

Mean confining pressure

\(\dot{p}{\prime }\)

Rate of effective stress

q

Deviator stress \((\sigma_1 - \sigma_3)\)

q0

First deviator stress applied (kPa)

q

Deviator stress increment

σ3

Effective confining stress

Δσ′3

Confining stress increment

Δσ′v

Stress increment in 1D compression

SIR

Stress increment ratio (Δq/q or Δσ3 3)

w0

Initial water content of specimen

wf

Water content at the end of the creep tests

ρ0

Density of specimen (g/cm3)

εvp

Volumetric strain at the end of the pre-consolidation

e0

Initial void ratio

εv

Volumetric strain

\(\dot{\varepsilon }_{\text{v}}\)

Volumetric strain rate

εa

Axial strain

\(\dot{\varepsilon }_{a}\)

Axial strain rate

εad

Undrained axial strain

\(\dot{\varepsilon }_{\text{ad}}\)

Undrained strain rate

u

Increase in pore pressure

α, β

Creep parameters

m

Slope of log \(\dot{\varepsilon }_{v}\) − log t plot (the rate of decrease in strain rate)

εr

Lateral strain

ν

Poisson’s ratio

Notes

Acknowledgement

The authors acknowledge the contribution of Canadian National Railways for providing both the project and funding support. This research was made possible through the (Canadian) Railway Ground Hazard Research Program and the Canadian Rail Research Laboratory (www.carrl.ca), both of which are supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), CPR, CN, American Association of Railroads Transportation Technology Center Inc. (AAR/TTCI) and Transport Canada; and an NSERC Discovery Grant.

Supplementary material

11440_2017_545_MOESM1_ESM.docx (348 kb)
Supplementary material 1 (DOCX 348 kb)

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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Mohan P. Acharya
    • 1
  • Michael T. Hendry
    • 1
  • C. Derek Martin
    • 1
  1. 1.Markin/CNRL Natural Resources Engineering FacilityUniversity of AlbertaEdmontonCanada

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