Events for CEGE Graduate Students

The department and the University host many events, lectures, and trainings of interest to CEGE graduate students. Please join us for events that interest you.

If you would like to have your events posted to this calendar, contact cegesps@umn.edu.

CEGE Graduate Students Newsletter Archive

Upcoming Warren Lectures

Subsurface Imaging and the Future of Geotechnical Site Investigation

A Warren Distinguished Lecture with 

Joseph Vantassel
Civil and Environmental Engineering, Virginia Tech

Abstract
Traditional geotechnical site characterization relies on interpolating between limited 1D measurements of subsurface stratigraphy to develop 3D engineering models for design. The sparsity of traditional 1D geotechnical measurements presents challenges in geological settings with rapid spatial variation (e.g., alluvial deposits) and/or anomalies (e.g., karst formations). However, on-going efforts continue to show that non-invasive seismic imaging methods can be used as a cost-effective means of improving geotechnical site investigation. In this presentation, Vantassel includes recent work to improve seismic imaging techniques for the problem of near-surface (i.e., depths < 30 m) geotechnical site investigation. Specifically, work on improving uncertainty quantification and accelerating data-processing with artificial intelligence (AI). The presentation highlights the application of techniques including the horizontal-to-vertical spectral ratio (HVSR), multichannel analysis of surface waves (MASW), and full waveform inversion (FWI) to civil engineering challenges including post-disaster reconnaissance, seismic site characterization, and cryosphere monitoring.

Speaker
Dr. Joseph P. Vantassel earned his BS in Civil Engineering from Rensselaer Polytechnic Institute (RPI) in 2016. For his graduate studies, Dr. Vantassel attended The University of Texas at Austin, earning his MS in May of 2018 and Ph.D. in December of 2021 in Civil Engineering. His graduate studies focused on the intersection of geotechnical engineering, geophysics, and computer science. After earning his Ph.D., Vantassel worked as a Research Associate in the Data Intensive Computing Group at the Texas Advanced Computing Center (TACC) until fall 2023. Dr. Vantassel is currently an Assistant Professor of Geotechnical Engineering in the Department of Civil and Environmental Engineering at Virginia Tech. He leads a group focused on advancing subsurface imaging toward more-robust and uncertainty-aware solutions through the intersection of field experiments, numerical simulation, artificial-intelligence, and high-performance computing.

Explaining Variations in the Onset of Sediment Motion

A Warren Distinguished Lecture with

Elowyn Yager
Civil and Environmental Engineering, University of Idaho

"Finding a Signal in the Noise: Using Turbulence, Bed Structure, and AI to Explain Variations in the Onset of Sediment Motion"

Abstract
Thresholds of sediment motion are integral to bedload transport estimates, which inform calculations of aquatic habitat, bridge pier scour, reservoir sedimentation, channel stability, and landscape evolution. Despite often being assumed constant, the critical Shields stress (stress needed to cause sediment motion), can vary by an order of magnitude between different gravel-bedded streams and even within the same river over time. This noise in critical Shields stresses obscures the mechanics of grain motion including the spatial and temporal variation of key processes that affect particle mobility. Using a combination of laboratory experiments, field measurements, and numerical modeling, Yager quantifies some of the key controls on particle motion. I specifically highlight the influence of flow turbulence and bed structure in controlling particle transport and incorporates aspects of these controls into a mechanistic theory. The theory is combined with simple photogrammetry and AI particle detection techniques to have an informed estimate of the onset of motion in any gravel bedded river.  Her results demonstrate that much of the noise in critical Shields stresses can be explained by including grain-scale mechanics in reach-scale estimates of sediment motion.  

Speaker
Elowyn Yager is a Professor in the Department of Civil and Environmental Engineering and the co-director of the Center for Ecohydraulics Research at the University of Idaho. Yager obtained her BS in Geology at SUNY Buffalo and her Ph.D. in Geology at the University of California at Berkeley. Yager’s research is focused on understanding the mechanics of geomorphic processes from the grain- to landscape scale including sediment and nutrient transport, post-fire hillslope erosion, bedrock erosion, and interactions between physical and ecological processes. She has received several awards for her research, teaching, and outreach including a National Science Foundation Career Award and a Fulbright Fellowship.