Dimitrios Zekkos, P.E., is an Associate Professor in the Department who joined UC Berkeley in January 2020. He has previously worked for a major consulting firm in the Bay Area and was a Faculty member at the University of Michigan as an Assistant and then Associate Professor. His research and scientific papers have been recognized by a number of Awards by organizations such as the American Society of Civil Engineers and the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). He is also founder of ARGO-E, an infrastructure informatics firm and a Board Member of Elxis Group, based in Greece, which is the entity behind Geoengineer.org. He serves as Chair of the ASCE Geo-Institute Geoenvironmental Engineering Technical Committee and Chair of the Innovation and Development Committee of the ISSMGE.
Prof. Zekkos' research interests span the fields of geotechnical engineering, geoenvironmental engineering and earthquake engineering. His research approach has commonly involved designing and employing innovative experimental (in the laboratory and the field), and computational approaches that aim to provide new insights and inform improved models of earth material response to static and dynamic loads.
Prof. Zekkos has also been devising and implementing autonomy-enabled approaches for characterization & post-disaster reconnaissance of infrastructure systems. His research team has deployed Unmanned Aerial Vehicles (UAV) to enable the development of large coverage, high resolution, spatially distributed datasets on the performance of infrastructure systems following natural disasters. These UAVs have been used to characterize not only the surface, but also the subsurface conditions by taking advantage of the capacity of UAVs to analyze the field data mid-flight and make mid-flight decisions autonomously. His research team has been successful in developing a UAV swarm-based approach for subsurface characterization using seismic geophysics, and specifically the Multichannel Analysis of Surface Waves (MASW) technique.
Prof. Zekkos has been conducting research on landslides using the latest technological tools for data acquisition and analysis. Sensor-equipped UAVs and satellites are used to generate high resolution topography for hundreds to thousands of square kilometers. High resolution optical and infrared data can be used to provide an assessment of rockmass characteristics, and moisture conditions using digital image analyses in 3D. The data collected is used in 1D, 2D or 3D landslide models that span many square kilometers.
Prof. Zekkos has been also developing frameworks and objective criteria for the selection and modification of input ground motions that are used as input in seismic design of civil infrastructure. His research team explored the conditions under which time domain or frequency domain modified ground motions can result in â€œreasonableâ€ input ground motions, using thousands of ground motions.
Prof. Zekkos research thrust on Resiliency of Municipal Solid Waste (MSW) Landfills has been spanning more than 15 years and involved the development of characterization approaches and testing schemes to improve our understanding of the mechanical response of MSW. He has combined field and laboratory testing approaches to provide insights on material behavior. For example, in the laboratory, he co-developed a unique 300-mm diameter cyclic simple shear (CSS) with shear wave velocity measurements, and has conducted 300-mm diameter triaxial testing. In the field, he has used seismic geophysical techniques, such as the Multichannel Analyses of Surface Waves (MASW) and the Microtremor Analysis Methods, self-powered autonomous sensors for long-term deployment, and UAVs. He also characterized the nonlinear dynamic properties of MSW in-situ using the NHERI @UT large-size mobile vibroseis.
Prof. Zekkos is promoting energy harvesting in Next-Generation Municipal Solid Waste (MSW) Facilities, by investigating the physico-bio-chemical processes of anaerobic degradation of MSW. His research group developed large-size degradation simulators to degrade MSW specimens in anaerobic conditions with testing durations up to 1500 days. This testing guided the development of a coupled bio-chemo-physical computational performance model (CPM) and predicts energy output. Self-powered, autonomous, surface and subsurface distributed wireless nodes paired with land-based robots and UAVs provide critical input to this model.
More information about his research directions can be found here.
3D model of complex of landslides caused by 2015 Lefkada earthquake (left) and UAV conducting survey using optical, infrared and methane sensors (right).
Left: Vibroseis to shake intensely soils and solid waste and assess the nonlinear dynamic properties of materials in-situ.
Right: 2D profile of shear wave velocity of solid waste.
Satellite-based mapping vs. modelled landslides for a 4 square kilometer area affected by an earthquake.
SEM imagery of incinerated material