Multiscale, Multiphysics Modelling of Granular Media: Bridging Continuum and Discrete Realms

Prof Jidong Zhao

The Hong Kong University of Science and Technology

Abstract: Granular media are ubiquitous in civil, mining, chemical, and energy systems. They defy conventional material classifications, exhibiting solid-like rigidity, fluid-like flow, and dynamic phase transitions. These complex behaviors, governed by multiscale interactions and multiphysics coupling (e.g., thermal-hydraulic-mechanical, THM), challenge traditional computational paradigms. This talk presents a transformative continuum-discrete coupling framework that synergizes the strengths of continuum methods (FEM, MPM, SPH) with physics-centric discrete approaches (DEM, contact dynamics, physics engines). It features a robust hierarchical coupling strategy enabling unprecedented insights into granular phenomena such as strain localization, liquefaction, and catastrophic failure, while addressing critical engineering challenges such landslides, permafrost-infrastructure collapse, carbon sequestration, and methane hydrate extraction. Through case studies, we demonstrate how this unified framework captures large deformations, multiphysics interactions, and emergent behaviors across scales. We further discuss how AI-augmented modeling may further empower the design and analysis in geomechanics and sustainable engineering.

Bio: Dr. Jidong Zhao is a Professor of Civil and Environmental Engineering at The Hong Kong University of Science and Technology (HKUST) and a Chang Jiang Scholar Chair Professor of China’s Ministry of Education. He holds a bachelor’s degree and Ph.D. in Civil Engineering from Tsinghua University. Dr. Zhao’s research bridges granular physics, advanced numerical methods, and geohazard mitigation. His work on multiscale, multiphysics modeling of granular systems has redefined predictive capabilities for industrial and environmental applications, from energy infrastructure resilience to climate-critical processes like carbon storage. Recognized globally, Dr. Zhao is a two-time recipient of the Scott Sloan Best Paper Award (2018, 2021), delivered the 2022 GeoCongress State of the Art (SOA) Lecture, and was honoured with the 2023 Invitational Fellowship from the Japan Society for the Promotion of Science (JSPS). He leads the computational geomechanics community as Co-Editor-in-Chief of Computers and Geotechnics, Section Editor for Granular Matter, and Associate Editor for the ASCE Journal of Engineering Mechanics.