Soil Mechanics at the Grain Scale with Applications to Bio-Cementation

Date:
Wednesday, May 16, 2018 - 12:00 pm

Location:
Center Hall 214

Sponsored By:
John McCartney

Speaker(s):
Dr. Matt Evans
Speaker photo

Seminar Flyer:
Abstract:

Particulate materials do not: have inherent strength and stiffness (like a solid); flow freely (like a liquid); or compress easily (like a gas).  The  unique  combination of  properties  possessed  by  granular  materials includes that they are: inherently multiphase, porous, and pervious; nonlinear and inelastic; their volume changes  during  shear;  and  strength  and  stiffness  depend  on  confinement,  strain  rate,  and  stress  path. Given these observations, particulate materials are effectively a separate phase of matter –neither solid, liquid, nor gas. Granular materials are not always amenable to continuum descriptions of behavior, so in some cases a discrete approach is adopted for modeling. Bio-cementation, a novel and promising approach for the stabilization of liquefiable sand deposits in-situ, will be used to motivate a broader discussion of grain-scale soil mechanics. The talk will begin by providing a survey of soils as assemblies of discrete particles and provide an introduction to the discrete element method  (DEM)  for  the  simulation  of  the  mechanical  behavior  of  granular  materials.  In  DEM  modeling, every grain in an assembly is modeled individually and simulation involves solution of Newton’s equations of  motion  for  every  particle  at  every  time  step.  After an introduction of modeling basics and a brief discussion of particle-continuum duality, the mechanical behavior of bio-cemented sands will be explored.

Speaker Bio:

Matt  is  an  Associate  Professor  in  the  School  of  Civil  and  Construction  Engineering  at  Oregon  State University.  Prior  to  coming  to  OSU  he  spent  six  years  as  an  Assistant  Professor  at  North  Carolina  State University.  His research interests include granular mechanics, multiphysics processes, quantitative stereology, image processing and morphology, soil mechanics, and geotechnical engineering. He serves on the editorial board of the ASCE Journal of Geotechnical and Geoenvironmental Engineering and Soils and Foundations. He is the chair of the Soil Properties and Modeling Committee of the ASCE Geo-Institute. He earned his M.S. and Ph.D. in civil engineering from the Georgia Institute of Technology, a B.S. in civil engineering from the University of New Mexico, and a B.A. in physics from the University of Virginia.


Contact:

Amber Samaniego

a2samaniego@ucsd.edu