Microscale characterization of energy dissipation mechanisms in liquefiable granular soils

This study utilizes the discrete element method (DEM) to present a microscopic energy monitoring approach to characterize energy dissipation mechanisms in seismically loaded soils. Numerical simulations were conducted on saturated deposits of granular particles subjected to seismic excitations, modeled using a transient fully-coupled continuum–fluid discrete-particle model. The onset of liquefaction is illustrated through macroscopic and microscopic response patterns. A novel in-depth look at the individual microscale energy components both before and after the onset of liquefaction is presented. Local microscopic energies are also presented and are compared with local macroscopic energies calculated from stress–strain loops. Finally, an assessment of existing hypotheses to quantify liquefaction potential based on energy consideration is presented through a discussion of a number of simulations that resulted in liquefaction.