Evidences of the effects of free gas on the hydro-mechanical behaviour of peat

C. Jommi*, S. Muraro, E. Trivellato, C. Zwanenburg

*Corresponding author for this work

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

3 Citations (Scopus)

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.

Original languageEnglish
Title of host publicationAdvances in Laboratory Testing and Modelling of Soils and Shales, ATMSS 2017
PublisherSpringer
Pages112-119
Number of pages8
ISBN (Print)9783319527727
DOIs
Publication statusPublished - 2017
EventInternational Workshop on Advances in Laboratory Testing and Modelling of Soils and Shales, ATMSS 2017 - Villars-sur-Ollon, Switzerland
Duration: 18 Jan 201720 Jan 2017

Publication series

NameSpringer Series in Geomechanics and Geoengineering
ISSN (Print)18668755
ISSN (Electronic)18668763

Conference

ConferenceInternational Workshop on Advances in Laboratory Testing and Modelling of Soils and Shales, ATMSS 2017
Country/TerritorySwitzerland
CityVillars-sur-Ollon
Period18/01/1720/01/17

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