Numerical modeling of fault and rupture co-evolution using a damage-breakage rheology with granular rate-and-state friction
- 1LMU Munich, Geophysics, Earth and Environmental sciences, Munich, Germany (casper.pranger@gmail.com)
- 2Scripps Institution of Oceanography, UC San Diego, La Jolla (CA), USA
- 3Dept. of Civil, Environmental and Geomatic Engineering, ETH Zurich, Switzerland
- 4Dept. of Earth Sciences, University of Southern California, Los Angeles (CA), USA
A recently developed continuum formulation of rate and state friction (Pranger et al., 2022) treats fault friction as an internal flow process in a granular medium, instead of its conventional treatment as a sliding process on a surface between juxtaposed rocks. The spurious mesh dependency that is typically associated with strain softening rheologies is avoided by including a diffusion process with an associated diffusion length scale.
We show that this granular rate and state friction law can be understood as a flow involving the breakage component of the damage-breakage rheology (DBR) of Lyakhovsky and Ben Zion (2014a,b). Modeling the episodic transitions from local damage accumulation in the solid to the fluid-like granular flow phase during larger collective failure events, the DBR is both significantly broader in scope and better grounded in the thermodynamic theory of irreversible processes than the phenomenological rate and state friction law.
A promising next step is to consider the damage and breakage components simultaneously in coupled continuum models of fault and rupture co-evolution. Doing so at sufficient resolution requires highly performant algorithms and a specialized numerical treatment of the coupled non-linear partial differential equations, including a robust time integration scheme with adaptive step size control and a flexible implicit-explicit split. We aim to discuss our numerical methods and computing paradigms supported by proof-of-concept modeling results of interacting damage and breakage pulses in 2D.
References:
Pranger et al. (2022), Rate and state friction as a spatially regularized transient viscous flow law. Journal of Geophysical Research: Solid Earth, 127, e2021JB023511.
Lyakhovsky and Ben-Zion (2014a), Damage–breakage rheology model and solid-granular transition near brittle instability. Journal of the Mechanics and Physics of Solids, 64, 184-197.
Lyakhovsky and Ben-Zion (2014b), A Continuum Damage–Breakage Faulting Model and Solid-Granular Transitions. Pure and Applied Geophysics, 171, 3099–3123
How to cite: Pranger, C., May, D., Raess, L., Ben-Zion, Y., and Gabriel, A.-A.: Numerical modeling of fault and rupture co-evolution using a damage-breakage rheology with granular rate-and-state friction, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13815, https://doi.org/10.5194/egusphere-egu23-13815, 2023.
