Scaled physical modelling of mass movement processes on thawing slopes

Charles Harris, Brice Rea, Michael Davies

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

This paper presents initial results from scaled geotechnical centrifuge modelling of cryogenic slope processes. Four experiments are described in which 1/10 scale planar slope models were constructed from a silty soil at gradients of 12°, 18°, and 24°. Models were frozen on the laboratory floor, and thawed in the centrifuge at 10 gravities. Frost heave, thaw settlement, soil temperature and pore water pressures were recorded. In each experiment, ten columns of 5 mm long plastic cylinders inserted through the soil profile allowed surface soil displacements to be determined, and indicated displacement profiles with depth at the end of each experiment. The 12° model was subjected to four cycles of freezing and thawing, simulating four annual active-layer freeze - thaw cycles. During each thaw phase, gelifluction occured, and average model-scale surface displacements were 18.7 mm/cylce (equivalent to 187 mm/cycle at prototype scale). In the 18° model gelifluction rates were higher, with average surface displacements of 65.1 mm/cycle at model scale, 651 mm/cycle at prototype scael. Two replicate 24° frozen slope models were tested in the centrifuge, and thawing was associated with failure by mudflow. Maximum pore water pressures during thaw were similare in all models. Slope stability analysis using an infinite planar model indicated that the factor of safety against failure remained > 1 in the 12° model, was close to or slightly less than 1 in the 18° model, and was < 1 in the 24° models.

Original languageEnglish
Pages (from-to)125-135
Number of pages11
JournalPermafrost and Periglacial Processes
Volume12
Issue number1
DOIs
Publication statusPublished - 17 Apr 2001

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mass movement
thawing
modeling
centrifuge
porewater
frost heave
centrifugal model test
freeze-thaw cycle
silty soil
mudflow
active layer
experiment
slope stability
stability analysis
soil temperature
freezing
soil profile
soil surface
plastic
gravity

Keywords

  • Centrifuge modelling
  • Gelifluction
  • Mass movement
  • Mudflow
  • Thawing slopes

ASJC Scopus subject areas

  • Geology

Cite this

Scaled physical modelling of mass movement processes on thawing slopes. / Harris, Charles; Rea, Brice; Davies, Michael.

In: Permafrost and Periglacial Processes, Vol. 12, No. 1, 17.04.2001, p. 125-135.

Research output: Contribution to journalArticle

Harris, Charles ; Rea, Brice ; Davies, Michael. / Scaled physical modelling of mass movement processes on thawing slopes. In: Permafrost and Periglacial Processes. 2001 ; Vol. 12, No. 1. pp. 125-135.
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