The recent “Report on Mount Polley Tailings Storage Facility Breach” by the Independent Expert Engineering Investigation and Review Panel highlights the need for improved professional practice for tailings dam site characterization in BC. The primary goals of the proposed one-day seminar are to provide an overview of the key geological issues to do with the spatial distribution and continuity for lacustrine soils in glaciated BC valleys and to summarize the Best Available Technologies for geotechnical characterization. The course will be presented in three parts:
- Present an overview of BC Quaternary geology with focus on distribution/stratigraphy of lacustrine lake bed sediments in valley fill deposits,
- Provide guidance on Best Available site investigation techniques with a focus on Cone Penetration Testing (CPT) and soil profiling, and
- Review of tailings dam case histories that illustrate a range of different foundation conditions with a focus on developing a conceptual geology model, phased site investigation programs, failure modes analysis and the observational method.
The seminar should be of interest to tailings dam designers; mine operators, regulators, and others involved with tailings dams in BC. Information will be presented at a summary level in order to provide a broad understanding of the key geological issues and the technologies required to support a defendable design basis. Specialized expertise in engineering geology, dam engineering, and/or stability analysis is not required.
BC Quaternary Geology: BC glacial history overview. Morphology and depositional features of different types of lacustrine deposits (supra-glacial, englacial, ice marginal, etc.). Geologic history and influencing engineering geology issues. Examples of some well-studied valley fill deposits in BC.
Site Investigation Techniques: Risk based site characterization strategy. Use and application of Cone Penetration Testing (CPT) for fine grained deposits. Best Available Technologies for drilling and sampling. Examples illustrating use of CPT data as a stratigraphic profiling tool.
Case Histories: Review of relevant case histories involving mine waste embankments on glacial soils foundations including thick compressible lacustrine sediments, thin pre-sheared clays and permafrost sediments. Each of the case histories will be outlined to demonstrate the importance of integrating foundation geology with the site characterization program. The value of a phased site investigation approach coupled with failure modes analysis will be illustrated.
Dr. John Clague, P.Geo
Simon Fraser University
John Clague is an authority in Quaternary and environmental earth sciences. He is Professor Emeritus in the Department of Earth Sciences at Simon Fraser University and formerly a Research Scientist with the Geological Survey of Canada. Dr. Clague has 40 years of experience in surficial/terrain mapping, Quaternary stratigraphic investigations, engineering and environmental interpretations of surficial geological information, and natural hazard studies. He has influenced Quaternary scientists in the United States and Europe and his research on earthquakes, landslides, and floods have greatly increased public and official awareness of these hazards.
Dr. Richard Dawson, P.Eng.
Richard Dawson is a geotechnical engineering consultant with over 30 years of experience in geology, mining, and geotechnical engineering related to resource development. Dr. Dawson’s technical expertise is in mine waste geotechnics (waste dumps and tailings), slope stability (rock and soil), and risk evaluations. He is the geotechnical practice leader for Norwest Corporation, an international mining and energy consultancy. Richard has an extensive resume of design and design review projects involving complex site investigations for mine waste embankments, including those involving glacial foundations. He will provide the Case History portion of the seminar.
Dr. Peter Robertson, P. Eng.
Gregg Drilling & Testing, Inc. (Canada)
Peter Robertson brings more than 40 years’ experience as an educator, researcher, consultant and practitioner specializing in the areas of in-situ testing and site investigation, earthquake design of geotechnical structures, and soil liquefaction. Peter is recognized as an expert both nationally and internationally in the areas of in-situ testing and soil liquefaction. He has been a consultant to various clients for projects involving liquefaction evaluation for major structures, stability of on-shore and off-shore structures, landslides, stability of natural slopes and tailings dams, and use and interpretation of in-situ tests. He is the co-author of the primary reference book on Cone Penetration Testing (CPT). He has also authored or co-authored over 250 publications as well a popular CPT Guide that is freely available via a number of websites. Peter has also assisted in the development of several inexpensive CPT-based interpretations software programs and has presented a series of free webinars on the CPT in an effort to enhance education and practice.