Triaxial stress path tests on artificially prepared analogue alpine permafrost soil
Some degrading rock glaciers have been exhibiting deepening depressions, accelerating strain rates and, in some rare cases, sudden release of mass movements. Warming permafrost already mobilises lower strength as temperatures rise, however unusual stress paths with lateral stresses greater than vert...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
NRC Research Press (a division of Canadian Science Publishing)
2018
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1807/95784 http://www.nrcresearchpress.com/doi/abs/10.1139/cgj-2017-0737 |
| Summary: | Some degrading rock glaciers have been exhibiting deepening depressions, accelerating strain rates and, in some rare cases, sudden release of mass movements. Warming permafrost already mobilises lower strength as temperatures rise, however unusual stress paths with lateral stresses greater than vertical stresses, instead of vice versa, could exacerbate this with lower strength at failure, and hence higher vulnerability. This paper investigates the mechanical behaviour of artificially frozen soil specimens at temperatures between -3.0 and -0.3°C under various stress paths, axial (A) and lateral (L), compression (C) and extension (E), for total stress paths AC, AE, LE, LC. Acoustic emissions were detected during shearing in order to expose how the deformation mechanisms develop from a microstructural point of view. Deviatoric stress mobilised in the stress path tests was linearly dependent on the temperature (within the ranges tested): a temperature increase resulted in a decrease in residual deviatoric stress. Comparison between the residual deviatoric stresses obtained from the different stress path tests indicates that 1) values mobilised with radial stress greater than axial stress were lower than vice versa, 2) more strength was mobilised when changing lateral stress paths than axial, with 3) the lowest strength mobilised in AE beneath a depression. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author. |
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