SCEC Award Number 24170 View PDF
Proposal Category Individual Research Project (Single Investigator / Institution)
Proposal Title Co-evolution of earthquakes and fault zones in a fault network model
Investigator(s)
Name Organization
Ahmed Elbanna University of Illinois at Urbana-Champaign
SCEC Milestones B2-2, B3-3, C2-1 SCEC Groups FARM, SDOT, RC
Report Due Date 03/15/2025 Date Report Submitted 03/30/2025
Project Abstract
 Existing literature typically models faults as pre-existing interfaces governed by various friction laws. Field observations reveal that a typical fault zone comprises a fine-grained inner core bordered by a gouge layer and enveloped by both damaged and intact host rock. Simulating and understanding the spatial and temporal evolution, propagation, and interactions of these damage volumes is therefore of great interest. To address this, we have extended the computational framework for modeling the quasi- and fullydynamic
evolution of inelastic strain (represented as slip in a planar formulation) in both 2D and 3D models. Our extension incorporates continuum damage breakage rheology into finite deformation kinematics, thereby enabling simulations of large deformations pertinent to the earthquake cycle. The continuum damage breakage model (CDBM) accounts for changes in elastic moduli during brittle deformation and captures phase transitions during dynamic failures using state variables for damage (cracking) and breakage (granulation). It partitions strain energy between a damaged (visco-)elastic solid phase and a granular phase, offering a more realistic representation of fault zones by explicitly modeling the nucleation and growth of damage bands. Our results suggest initial success in modeling fault evolution over seismic and aseismic time scales coupled with main shock and aftershock activities.
Intellectual Merit We have developed a thermodynamically consistent finite deformation formulation for the Continuum Damage Breakage Model. We have verified the implementations of both explicit and implicit time integration schemes of such a model. Initial results from implementing the model with an earthquake cycle framework suggests that the model is capable of capturing fault evolution and growth, branching, and aftershock generation demonstrating the potential of investigating the co-evolution of fault zones and seismicity.
Broader Impacts This research provided training opportunities for two PhD students: Chunhui Zhao and Amr Ibrahim. The codes developed as part of this research are made available on the science gateway Quakeworx. Understanding the coevolution of fault zones and seismicity across spatial and temporal scales is imperative for developing next generation seismic hazard models and investigating uncertainties in seismic catalogs.
Project Participants Chunhui Zhao : PhD student, Civil and Environmental Engineering, UIUC
Amr Ibrahim: PhD student, Civil and Environmental Engineering, UIUC
Exemplary Figure Figure 3: Particle velocity and breakage variable time snapshots. (a) particle velocity (b) breakage variable
Linked Publications

Add missing publication or edit citation shown. Enter the SCEC project ID to link publication.