Towards Developing Constitutive Models for Hydro-Mechanical Behaviour of Faults

Abstract:

In the shallow brittle crust the observations are clear that the seismic wave speeds of the medium around the fault drop dramatically after an earthquake. The permeability structure around a fault zone is anisotropic and non-uniform as a function of distance from the fault zone. Thus it is not surprising to expect a full non-linear hydro-mechanical coupling between dynamic earthquake ruptures and the surrounding off-fault medium. Another potential benefit in understanding non-linear hydro-mechanical coupling between dynamic earthquake ruptures and the surrounding off-fault medium is in properly characterizing the relationship between underground storage/waste disposal and induced seismicity. We will present on going work on developing micro-mechanics based constitutive models for brittle (fracture dominated) medium that account for evolution of the mechanical and hydraulic properties at high-strain rates.