Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to Rapid Fault Shearing

Jean Sulem (1) , Paul Lazar (1) , Ioannis Vardoulakis (2)

1 CERMES - Centre d'enseignement et de recherche en mécanique des sols
2 Faculty of Applied Mathematics and Physics

In this paper, the mechanism of fault pressurization in rapid slip events is analyzed on the basis of a complete characterization of the thermo-poro-mechanical behavior of a clayey gouge extracted at 760m depth in Aigion fault in the active seismic zone of the Gulf of Corinth, Greece. It is shown that the thermally collapsible character of this clayey gouge can be responsible for a dramatic reduction of effective stress and a full fluidization of the material. The thickness of the 'ultra localized' zone of highly strained material is a key parameter that controls the competing phenomena of pore pressure increase leading to fluidization of the fault gouge and temperature increase leading to pore fluid vaporization.

Mots clés: fault; clayey gouge; thermo-poro-mechanical couplings; seismic slip

Domaines: Mécanique des solides [physics.class-ph]; Mécanique des solides [physics.class-ph]; Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Jean Sulem, Paul Lazar, Ioannis Vardoulakis. Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to Rapid Fault Shearing. International Journal for Numerical and Analytical Methods in Geomechanics, 2007, 31 (3), pp.523-540. ⟨hal-00311371⟩