F. Estéfan T. Garcia

My primary research interests are in the realm of granular materials and granular systems. Granular and particulate materials represent some of the most heavily manipulated materials in our society. A fundamental understanding of their behavior at the scale of individual grains or particles has wide-ranging benefits in several fields including civil engineering, geology, additive manufacturing and planetary exploration.

My research relies on advanced numerical modeling techniques that can simulate large-strain behavior while also capturing directly the fundamental discontinuous nature of granular systems. Specifically, I utilize the Distinct Element Method (DEM) with high-performance computing to simulate individual grain interactions within a particle assemblage as it undergoes large-strain deformation due to phenomena such as earthquake surface fault rupture and trapdoor displacement. This line of research advances understanding of how ground surface deformations can impact infrastructure and ultimately aims to improve the resiliency of infrastructure against geologic hazards.

I also use state-of-the-art imaging techniques to characterize the fabric of granular materials in terms of the shapes and sizes of individual grains, the orientations of individual grains and their packing arrangement. I use high-resolution x-ray computed tomography (XRCT) to image the grains within samples of natural sediment for the purpose of characterizing how grain fabric is affected by its depositional history. By imaging sediment samples at incremental stages of shear deformation, this research further informs how the macroscopic deformation behavior of granular sediment is influenced by its fabric at the scale of individual grains.

Former Recorder for and current member of the Geotechnical Extreme Events Reconnaissance (GEER) Association

• National Science Foundation Graduate Research Fellowship, 2014
• Chancellor’s Fellowship, University of California, Berkeley, 2013
• summa cum laude, University of California, Los Angeles, 2013
• Engineering Achievement Award for Student Welfare, University of California, Los Angeles, 2013
• Tau Beta Pi Engineering Honor Society, 2013

• Garcia, F. E., & Bray, J. D. (2019). “Discrete-Element Analysis of the Influence of Granular Soil Density on Earthquake Surface Fault Rupture Interaction with Rigid Foundations,” Journal of Geotechnical and Geoenvironmental Engineering, 145(11), 04019093.
• Garcia, F. E., & Bray, J. D. (2019). “Discrete element analysis of earthquake fault rupture-soil-foundation interaction,” Journal of Geotechnical and Geoenvironmental Engineering, 145(9), 04019046.
• Bray, J.D., Frost, J.D., Rathje, E.M, & Garcia, F.E. (2019). “Recent advances in geotechnical post-earthquake reconnaissance.” Frontiers in Built Environment – Earthquake Engineering, 5, 5, doi: 10.3389/fbuil.2019.00005.
• Garcia, F.E., & Bray, J.D. (2019). “Modeling the shear response of granular materials with discrete element assemblages of sphere-clusters.” Computers and Geotechnics, 106, 99-107, doi: 10.1016/j.compgeo.2018.10.003.
• Garcia, F.E., & Bray, J.D. (2018). “Distinct element simulations of shear rupture in dilatant granular media.” Int. J. of Geomechanics, 18(9), 04018111, doi: 10.1061/(ASCE)GM.1943-5622.0001238.
• Garcia, F.E., & Bray, J.D. (2018). “Distinct element simulations of earthquake fault rupture through materials of varying density.” Soils and Foundations, 58(4), 986-1000, doi: 10.1016/j.sandf.2018.05.009.