To follow up our previous experiment on densely packed granular particles [Phys. Rev. Lett. 126, 128001 (2021)], we drive Polydimethylsiloxane (PDMS) particles in a circularly-shear cell and perform 3D tomography using a laser sheet scanning at frequencies up to 40 Hz. The geometry of the shear cell in tandem with the video-rate tomography allows us to obtain a 3D map of particle trajectories and capture quake events as in sudden, system-spanning displacements of particles. Identifying such events are substantial to our understanding of geological hazards and dense granular flow in general, while further characterization and statistics may unveil clues to the mechanisms of quaking.
Keywords: Granular Flow, Quaking, Shear Flow