Timothy D. Stark is a Professor of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign with an expertise in Geotechnical Engineering. Dr. Stark has been conducting interdisciplinary research and teaching on the static and seismic stability of natural and manmade slopes, such as dams, levees, floodwalls, and waste containment facilities, railroad geotechnics, geosynthetics and geomembranes, soil liquefaction during earthquakes, and stabilization and behavior of dredged material containment areas. He is currently researching three-dimensional slope stability, inverse analyses of landslides, heating events in waste containment facilities, and jet grouting. Dr. Stark has received a number of awards for his research, teaching, and service activities and was selected as the 2022-2023 Cross-USA Lecturer by the Geo-Institute (G-I) of the American Society of Civil Engineers. The Cross-USA Lecturers are selected based on a range of criteria, including prestige in the geoprofessional community, professional achievements, and lecture abilities.
This presentation will discuss the investigation and analysis for an underwater retrogressive slope stability failure caused by concurrent construction of a wharf access causeway and dredging near the end of the causeway for the wharf structure. A cross-section was developed along the causeway and analyzed to simulate the retrogressive slope failure using limit equilibrium. The compound failure surface for the inverse stability analysis of each of the five retrogressive slide masses is in agreement with observations before, during, and after the failure. Soil stratigraphy is discussed and the mobilized undrained strength of the seabed clay underlying the causeway fill was estimated using an inverse analysis of the five slide masses.