Séminaire

Mardi 22 Octobre 2024 à 11h00.

Lab-Scale Earthquakes and Creep Behavior in Granular Materials

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In this seminar, I will present the work I carried out during my PhD, which is divided into two parts: the study of lab-scale earthquakes and the investigation of creep behaviour in granular materials. In the first part, we recreate a lab fault by subjecting a granular sample of glass beads to biaxial compression. During the stationary phase after deformation localizes into shear bands, we use interferometry to observe local plastic deformations and define lab earthquakes. These lab-scale earthquakes exhibit similar characteristics to real seismic events, with individual slips accumulating to produce total displacement. Their magnitude distribution follows a power law (Gutenberg-Richter law), and they present an aftershock-like behaviour. Importantly, we show that this aftershock effect is driven by deformation rather than time.
In the second part, I will discuss the creep behaviour observed in granular materials under constant stress. The system undergoes three stages: deceleration, stabilization, and eventual acceleration toward failure. This behaviour follows scaling laws observed in many materials and we are starting to study its dependency on several parameters such as the difference between the applied stress and the failing stress of our samples.

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