From Stress Chains to Acoustic Emission.

Area of Science:

• Geophysics
• Computational Mechanics
• Materials Science

Background:

• Earthquake systems involve complex interactions within geological formations.
• Granular materials exhibit unique mechanical behaviors under stress.
• Understanding shear resistance and failure mechanisms is crucial for seismic studies.

Purpose of the Study:

• To investigate the behavior of a granular layer within an earthquake system model.
• To analyze the emergence and role of stress chains during shear events.
• To explore the potential of acoustic emissions as a monitoring tool for granular layers.

Main Methods:

• Utilized a combined finite-discrete element method for numerical simulations.
• Modeled an earthquake system with a granular layer embedded in a formation.
• Applied shear-driven forces to the formation to induce layer deformation.

Main Results:

• Observed the formation of stress chains within the granular layer under shear.
• Demonstrated that stress chains provide resistance to shear forces.
• Identified acoustic emissions as broadcasts resulting from stress chain failure.

Conclusions:

• Stress chains are key structural elements in sheared granular layers within earthquake models.
• Acoustic emissions serve as a viable remote sensing method for monitoring the condition of granular layers in seismic systems.
• The numerical scheme effectively captures the complex dynamics of stress chain formation and failure in granular earthquake systems.