October 6, 2022

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Jenny Ramirez and Sean O'Donnell to Present on Dam Breach and Inundation Analysis at the Canadian Dam Association 2022 Annual Conference

Jenny Ramirez, Ph.D., (Ontario) and Sean O'Donnell, Ph.D., P.E. (Maryland) will present "Dam Breach and Inundation Analysis for the Tailings Storage Facility at a Gold Mine in West Africa" at the Canadian Dam Association's (CDA) Annual Conference at the St. John's Convention Centre in St. John's, Newfoundland at 2:30 p.m. on October 18, 2022.

Jenny and Sean's coauthors are David Espinoza and Jeremy Morris, Geosyntec Consultants.

Jenny Ramirez is a Project Professional in Ontario, Canada, whose experience includes site characterization, data visualization, and numerical modeling for solving geotechnical engineering related problems and facilitating decisions in the design or assessments of dams, landfills, disposal containment facilities, and other earth structures. Dr. Ramirez's experience also includes task automation, geotechnical instrumentation interpretation, seismic response analyses, soil-foundation-mitigation-structure interaction analyses on liquefiable soils, forensic analyses, and reconnaissance evaluations after extreme natural disaster. Dr. Ramirez has developed numerous site conceptual models by synthetizing large geotechnical databases from both historical pre-construction and post-construction, field and laboratory, geotechnical investigations. She has performed geotechnical characterization for different purposes: to prepare seismic microzonation maps, to evaluate the cause of failures dams and slopes, and to analyze geotechnical analyses of shallow and deep foundations. She has extensively worked on the development of 2D and 3D visualization tools and the automation of instrumentation results presentations to improve project team efficiency on interpretation of both large instrumentation network and numerical modeling results. Dr. Ramirez has also led the numerical analyses of multidisciplinary projects including bridges, buildings, and highways, using OpenSees, Plaxis, Deepsoil, Shake, GeoStudio, Slide, Group, LPile, and Shaft. She is an active member of the Geotechnical Extreme Event Reconnaissance (GEER) Team, where she has conducted site reconnaissance after major natural events to identify failure triggering and disaster consequences. She has also experience on computational coding using tcl, Matlab, and Python.

Sean O'Donnell is a Project Engineer at Geosyntec's Columbia, Maryland office. He joined Geosyntec after graduating with his Ph.D. and serving as a postdoctoral researcher at Arizona State University. Dr. O'Donnell's practical experience includes geotechnical and environmental design, analysis, and monitoring of waste containment structures. Dr. O'Donnell's research background involves the study of biologically-mediated ground improvement techniques through both laboratory-based experiments and the development and analysis of computer simulations. His Ph.D. dissertation focused on the use of denitrifying microorganisms for the mitigation of earthquake-induced soil liquefaction as a two-stage process through desaturation and microbially induced carbonate precipitation.

The Canadian Dam Association (CDA) holds an annual conference in the fall with keynote presentations, technical papers and workshops, with supplier exhibits. The annual conference is the focus for exchange of information and experience during the year and provides superb opportunities for networking. Technical papers presented at past conferences are available for download by CDA Members. In addition to the annual conference, regional workshops and events organized by local groups. CDA Technical Committees and Working Groups produce publications including guidelines and technical bulletins on topics such as Dam Safety and Public Safety Around Dams.

The Canadian Dam Association (CDA) is a group of Owners, Operators, Regulators, Consultants and Suppliers interested in dams and reservoirs. CDA provides a forum for the exchange of ideas and experience in the field of dam safety, public safety and protection of the environment. The Canadian Dam Association envisions a future in which all dams are safe, well-managed and benefit society.

Abstract

As part of the final closure planning for an existing tailings storage facility (TSF) at a gold mine in West Africa, a dam breach analysis was performed to assess potential downstream impacts associated with a hypothetical breach of the TSF embankment and associated flow of liquefied tailings. Because historic flow slides from failed TSF embankments have led to catastrophic ecological and material damage as well as loss of life several miles downstream from the failure (e.g., at Brumadinho and Mount Polley), the mine owner was concerned about the potential environmental, material, financial, and human impacts of a TSF embankment failure and subsequent tailings flow on downstream communities and the local environment. To perform the analysis, multiple failure modes for the TSF embankment were considered, laboratory experiments were performed to determine the rheological properties of the tailings, and a pseudo three-dimensional non-Newtonian fluid mechanics model was developed to predict the extent of inundation from a hypothetical flow slide. The fluid mechanics model combines an analytical two-dimensional model to develop the profile along the flow path with empirical relationships for cross-sectional shape. Analyses were conducted for two sets of initial conditions to assess uncertainty in material properties and input assumptions. Results showed that communities located approximately six to ten miles downstream of the TSF would be impacted within five to ten minutes following a hypothetical failure. As such, the following recommendations were made: improve stability monitoring at the TSF, improve TSF stability, and investigate diversion strategies for a hypothetical flow slide.

More Information

About the event: CDA Conference 2022 - Canadian Dam Association (CDA-ACB)
About CDA-ACB: Home - Canadian Dam Association (CDA-ACB)
For consultation regarding Dam Breach Analysis, contact Jenny at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Jenny: Jenny Ramirez | LinkedIn