Learning from Sand: How natural extremes inspire adaptive geomaterial models

A Warren Distinguished Lecture with Giuseppe Buscarnera Civil Engineering, Northwestern University ABSTRACT Granular matter, the most widely deployed solid substance on Earth, has unique features that render it adaptive to changes in pressure and density. Sand, the most ubiquitous class of natural granular solids, is an essential template to study this broad class of materials. Yet, the complex interaction between grain-scale processes and their bulk-averaged (i.e., continuum) properties has historically hindered the definition of structure-property relationships that can reconcile sand classification protocols with the mathematical models used to interpret and simulate phenomena at the scale of infrastructures or geosystems. This talk delves into this major challenge and outlines a series of multi-scale modeling and testing procedures aimed at recovering macroscopic bulk properties from particle-scale attributes, such as the size, shape, mineralogy, and statistical dispersion of sand grains. By taking inspiration from natural extremes, such as the particulate microstructure of fault gouges and planetary impact sites, it will be shown that suitable state variables can be introduced to explain and simulate the adaptivity of sand to external stress, thus opening new avenues for underground characterization, exploration of remote sites, infrastructure installation, and the design of new materials. SPEAKER Giuseppe Buscarnera is a Professor of Civil Engineering at Northwestern University, which he joined in 2011. He received his BSc and MS in Civil Engineering from the Politecnico di Milano, Italy, and a PhD in Geomechanics from the Politecnico di Torino, Italy. Buscarnera's research focuses on geomechanics, geohazards, granular materials, and multi-physics of porous media. He is the PI of numerous sponsored research projects on these topics, serves as chairman of the Soil Properties and Modeling committee of the ASCE Geo-Institute, and is the Editor-in-Chief of the journal Géotechnique Letters. Buscarnera’s research has been awarded with the Faculty Early Career Development Award (CAREER) from the National Science Foundation and the Arthur Casagrande award of the American Society of Civil Engineering (ASCE). Category: Geomechanics