Abstract: One of major concerns when constructing within karst terrain in Central Florida is the possibility of sinkholes (either cover-subsidence and –collapse types), which can create significant economic loss and structural damage to buildings and infrastructures. Because of these karst geohazards, proper site characterization, particularly geotechnical subsurface exploration, is essential to ensure a practical yet safe design during construction phases and the project’s life span. In this talk, the author presents geotechnical engineering methods that quantitatively evaluate the vulnerability/stability of sinkholes via cone penetration test (CPT). The presenting two methods are (1) a raveling chart that not only delineates the raveled and non-raveled zones but also determine the levels of raveling severity that correspond to multiple data zones and (2) a sinkhole index, Sinkhole Resistance Ratio (SRR), which is a function of encountered soil resistance values, such as cone tip resistance (qc), as well as encountered stratigraphy thicknesses of the soft-soil anomalies. Both chart and index diagnose site’s sinkhole vulnerability, thus help engineers make immediate and proper decisions. Case studies demonstrating the successful applications of the chart and index are presented.
Bio: Dr. Boo Hyun Nam is an Associate Professor in Civil, Environmental, and Construction Engineering (CECE), Director of Sinkhole & Subsidence Laboratory (SSL), at University of Central Florida (UCF). He received his Ph.D. in Civil Engineering at The University of Texas at Austin. Over the years, Dr. Nam has conducted research in the areas of remote sensing, sinkhole and subsidence, geomaterials & geotechnology, infrastructure materials, and pavement engineering. Dr. Nam currently serves in multiple technical committees, including ASCE Geotechnical-Institute (GI) and Transportation Research Board (TRB), and organization committees of The Sinkhole Conference, AEG Karst Hazards Forum Conference, and so on. Over the years, Dr. Nam has graduated 9 PhDs and 8 MSs and currently advising 4 PhD students. He has published more than 150 papers in peer-reviewed journals and conferences. He has been invited as keynote speakers at international conferences/workshops in the Middle East, East Asia, and the United States. Dr. Nam has been serving as the faculty advisor of the ASCE-UCF Student Chapter and was awarded the Faculty Advisor of the Year in 2016 by ASCE Florida.
More details at: https://unl.zoom.us/j/99871965704