  The Dieterich-Ruina rate-and-state friction model is transferred to a bulk
variant and the state variable (aging) influencing the dissipation mechanism is
here combined also with a damage influencing standardly the elastic response.
As the aging has a separate dynamics, the overall model does not have a
standard variational structure. A one-dimensional model is investigated as far
as the steady-state existence, localization of the ataclastic core, and its
time response, too. Computational experiments with a damage-free variant show
stick-slip behavior (i.e. seismic cycles of tectonic faults) as well as stable
slip under very large velocities.
