Understanding Multi-Physics Repetitive Loads: From Biology to Geotechnical Engineering 

Dr. J. Carlos Santamarina, Professor at Georgia Tech, presents his talk "Understanding Multi-Physics Repetitive Loads: From Biology to Geotechnical Engineering and Resource Recovery".
Abstract: Most natural and engineered systems experience repetitive loading cycles of various kinds, including stress (our bones, foundations and reservoirs), fluid pressure (the beating of our hearts, tidal action, and pumped hydro storage), suction (our lungs, natural dry-wet cycles, water-alternating-gas injection), pore fluid chemistry (salt-water intrusion), and thermal cycles (silos, cyclic CO2 injection, exposed rock faces, freeze-thaw processes, and geothermal systems). Repetitive loads can lead to significant accumulations of volumetric strain (towards the terminal void ratio) and plastic shear strains (shakedown or ratcheting), accelerate transport (heat, chemical species, and particles), and alter material properties and system performance. Complementary multi-scale experiments and simulations provide unique insights into the underlying mechanisms that explain the observed responses. Analysis and design must take into account the influence of multi-physics repetitive loads on the long-term performance, serviceability, and safety of engineered systems. While asymptotic trends can be applied to obtain first-order estimates for simple boundary conditions, complex boundary conditions necessitate numerical simulations, the development of new constitutive models, and the implementation of hybrid algorithms that avoid standard time-stepping numerical protocols.
Speaker Bio: Dr. J. Carlos Santamarina (Professor, Georgia Tech) earned his bachelor’s degree from the Universidad Nacional de Córdoba and completed graduate studies at the Universities of Maryland and Purdue. Throughout his career, he has taught at NYU-Poly, the University of Waterloo and KAUST. His research team combines experimental and numerical methods to investigate geomaterials in the context of energy geo-science and engineering, from resource recovery to energy and waste geostorage. He delivered the 50th Terzaghi Lecture on Energy Geotechnology and is a member of both Argentinean National Academies. He has received the ASTM's Hogentogler Award, the Korean Geotechnical Society Award, and Saudi Arabia's Tarek al-Qasabi Award.