Could faults be modelled with elastic materials ?

Antoine Mazuyer and Marianne Conin and Richard Giot and Paul Cupillard. ( 2015 )
in: The Geology of Geomechanics, London, The Geological Society

Abstract

A fault can be described as a mechanical heterogeneity in a medium. Stress orientation and magnitude are disturbed nearby it. This study focuses on faults with small deformation, induced by a low loading. We investigate if it is possible to model fault mechanical behaviour by inclusions with only elastic parameters. Finite Element Analysis is used to compute stress on 3D geological models with a linear elastic behaviour law. Simulation results are compared with reference data. Analytical models have established that compressive and extensive quadrants induced by a load are present nearby fault tips. Moreover, field observations have shown that faults are composed of two zones: a fault core surrounded by a damage zone. Both will be represented in the geological models. Elastic parameters evolve from the fault core to the end of the damage zone and the maximum principal stress rotates nearby the fault core. To represent at best the elastic properties repartition in the faults, we develop distribution functions to integrate these variations in the model. Finite Element Analysis manages to reproduce stress behaviour in the fault core, the damage zone and the fault tips.

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    BibTeX Reference

    @INPROCEEDINGS{,
        author = { Mazuyer, Antoine and Conin, Marianne and Giot, Richard and Cupillard, Paul },
         title = { Could faults be modelled with elastic materials ? },
         month = { "oct" },
     booktitle = { The Geology of Geomechanics },
          year = { 2015 },
     publisher = { The Geological Society },
      location = { London },
      abstract = { A fault can be described as a mechanical heterogeneity in a medium. Stress orientation and magnitude are disturbed nearby it. This study focuses on faults with small deformation, induced by a low loading. We investigate if it is possible to model fault mechanical behaviour by inclusions with only elastic parameters. Finite Element Analysis is used to compute stress on 3D geological models with a linear elastic behaviour law. Simulation results are compared with reference data. Analytical models have established that compressive and extensive quadrants induced by a load are present nearby fault tips. Moreover, field observations have shown that faults are composed of two zones: a fault core surrounded by a damage zone. Both will be represented in the geological models. Elastic parameters evolve from the fault core to the end of the damage zone and the maximum principal stress rotates nearby the fault core. To represent at best the elastic properties repartition in the faults, we develop distribution functions to integrate these variations in the model. Finite Element Analysis manages to reproduce stress behaviour in the fault core, the damage zone and the fault tips. }
    }