Hydromechanical behaviour of fine-grained calcilutite and fault gouge from the Aigion Fault Zone, Greece

This paper presents the experimental characterisation of hydraulic and mechanical properties of two fine-grained materials from the Aigion Fault Zone, on the southern shore of the Gulf of Corinth, Greece. One is a calcilutite, which commonly caps the basal limestone units, and the other is siliceous active fault gouge from 760 m depth in the borehole. Oedometric compaction/consolidation tests of unconsolidated cylindrical samples at variable stresses were conducted under drained conditions, and then permeability measured by a constant flow technique. The axial strain measurements show consolidation curves with a decelerating strain rate that can be approximated by a power-law function. The permeability is negatively and linearly correlated to the stress, and ranges from 9 to 15×10−18 m2 for the calcilutite and 0.9 to 2×10−18 m2 for the fault gouge with varied vertical stresses. To cite this article: I. Song et al., C. R. Geoscience 336 (2004).