The effect of internal gas pressurization on volcanic edifice stability: Evolution towards a critical state

Mark E. Thomas, Nick Petford, Edward N. Bromhead

Research output: Contribution to journalArticle

Abstract

Results from simple physical and numerical models investigating the effects of increased internal pore-fluid pressures of a Mohr–Coulomb volcanic edifice are presented. Physical experiments make use of a heap built from angular sand on top of a stiff substrate of variable angle, with the provision for injection of internal fluid (gas) pressures into the base. The resulting failure geometries arising from internal pressurization of the model appear similar to some natural examples of sector collapse. Two-dimensional limit equilibrium models analysing 42 500 possible failure surfaces were run with internal pressures (P0) in the range 5–35 MPa, and show that the potential critical failure surface migrates to increasingly deeper levels with increasing internal pressure. Although internal pressurization alone is unlikely to reduce the factor of safety (FS) below unity, the edifice is driven towards a state of criticality that will render in susceptible to any internal or external perturbations.
Original languageEnglish
Pages (from-to)312-317
Number of pages6
JournalTerra Nova
Volume16
Issue number5
DOIs
Publication statusPublished - 5 Nov 2004

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Pressurization
Gases
Fluids
Numerical models
Sand
Geometry
Substrates
Experiments

Cite this

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abstract = "Results from simple physical and numerical models investigating the effects of increased internal pore-fluid pressures of a Mohr–Coulomb volcanic edifice are presented. Physical experiments make use of a heap built from angular sand on top of a stiff substrate of variable angle, with the provision for injection of internal fluid (gas) pressures into the base. The resulting failure geometries arising from internal pressurization of the model appear similar to some natural examples of sector collapse. Two-dimensional limit equilibrium models analysing 42 500 possible failure surfaces were run with internal pressures (P0) in the range 5–35 MPa, and show that the potential critical failure surface migrates to increasingly deeper levels with increasing internal pressure. Although internal pressurization alone is unlikely to reduce the factor of safety (FS) below unity, the edifice is driven towards a state of criticality that will render in susceptible to any internal or external perturbations.",
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The effect of internal gas pressurization on volcanic edifice stability: Evolution towards a critical state. / Thomas, Mark E.; Petford, Nick; Bromhead, Edward N.

In: Terra Nova, Vol. 16, No. 5, 05.11.2004, p. 312-317.

Research output: Contribution to journalArticle

TY - JOUR

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AU - Bromhead, Edward N.

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