Presented by: Armin W. Stuedlein, Professor of Geotechnical Engineering
School of Civil and Construction Engineering, Oregon State University
This lecture will provide an overview of findings regarding the dynamic and cyclic behavior of the nonplastic and plastic silt soils in Southwest Washington and Western Oregon developed at Oregon State University over the last five years. Following an overview of the study sites and methods forming the basis for the study, existing liquefaction susceptibility criteria and a means for reliably quantifying liquefaction susceptibility is discussed. Typical hysteretic responses and corresponding cyclic resistances are presented. Relationships for estimating shear modulus reduction and damping curves, cyclic resistance ratios, and cyclic strength ratios will be presented. The response of two silt deposits with differing plasticity to seismic energy generated using controlled blasting and vibroseis shaking will be examined with a focus on excess pore pressure generation and shear modulus degradation, as well as the effects of partial drainage and excess pore pressure migration on dynamic and cyclic behavior. The similarities and differences between field and laboratory responses is examined within the limitations of local, three-dimensional seismic energy input.
Bio: Armin is a licensed professional engineer and Professor of Geotechnical Engineering in the School of Civil and Construction Engineering at Oregon State University. Armin received his MS and PhD in geotechnical engineering from Syracuse University (2003) and the University of Washington (2008), respectively. He joined the faculty at OSU in 2009 after consulting for Seattle-based firms, where he specialized in port and harbor engineering with an emphasis on foundation and earthquake engineering. His research has been published in over 150 peer-reviewed publications, and focuses on ground improvement and liquefaction mitigation, in-situ and laboratory-based testing for liquefaction and cyclic softening, experimental and numerical investigations of soil-structure interaction, and probabilistic geotechnical analyses. He is the Vice Chair of the Soil Improvement Committee (ASCE G-I), Editor at the ASCE Journal of Geotechnical and Geoenvironmental Engineering and the Journal of the Deep Foundations Institute, and Editorial Board member for Georisk and the Canadian Geotechnical Journal. Professor Stuedlein received the 2013 Deep Foundations Institute Young Professor Award, the 2015 Associate Editor of the Year Award for JGGE, and the 2017 ASTM Award for Outstanding Article on the Practice of Geotechnical Testing, among others.