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Evidences of the Effects of Free Gas on the Hydro-mechanical Behaviour of Peat

  • C. JommiEmail author
  • S. Muraro
  • E. Trivellato
  • C. Zwanenburg
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)

Abstract

Peats are soils containing a significant component of organic matter. Biochemical degradation of this fraction generates gases such as CO2, H2S and CH4, which tend to saturate the pore water eventually resulting in exsolution and expansion. The effects of these gases on the hydro-mechanical behaviour of peats are under investigation at Delft University of Technology. The results of a series of triaxial tests are discussed, in which gas was exsolved under controlled conditions by flushing natural samples with carbonated water, and undrained isotropic unloading and shear were performed. A significant reduction in the effective stress acting on the soil skeleton was observed during undrained unloading due to gas exsolution. However, different stages were observed in time, which appear to be ruled by the very high compressibility of peat. The mechanical response upon shearing is dominated as well by the ratio between the compressibility of the fluid and the soil skeleton. Although the ultimate strength does not differ much between the samples tested, the mobilised shear strength for a given axial strain does, which has to be accounted for cautiously in the choice for an operative shear strength.

Keywords

Volumetric Strain Triaxial Test Pore Fluid Peat Layer Peat Sample 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • C. Jommi
    • 1
    Email author
  • S. Muraro
    • 1
  • E. Trivellato
    • 1
    • 2
  • C. Zwanenburg
    • 3
  1. 1.Delft University of TechnologyDelftThe Netherlands
  2. 2.Laboratoire NavierÉcole Nationale des Ponts et ChausséesParisFrance
  3. 3.DeltaresDelftThe Netherlands

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