Investigation of the Feijão Tailings Dam Failure near Brumadinho, Brazil

Registration Closed

At approximately 12:28pm local time on January 25, 2019, tailings dam B-1 at Vale S.A.’s Corrego do Feijão Iron Ore Mine, located 9 kilometers north-east of Brumadinho, in the state of Minas Gerais, Brazil, suffered a sudden failure resulting in a catastrophic mudflow that travelled rapidly downstream resulting in significant damage and the loss of over 250 lives. This failure was unique in that there are high quality video images of the event that provide insight into the failure mechanism.

To determine what triggered the failure of this dam and why the failure occurred when it did, an Expert Panel carried out an investigation into the technical causes of the failure. The investigation included: (i) evaluating the nature and properties of the materials in the dam, (ii) assessing the dam construction and operation methods and their impact on the dam and tailings material properties, (iii) assessing the condition of the dam before and during the failure using analyses of available images, such as video, ground-based radar, LiDAR, satellite (InSAR and photographs), drone videos, and (iv) numerically modelling the conditions just prior to failure.

This presentation will provide a summary of the Expert Panel investigation carried out to determine the technical causes of the failure.

Learning objectives

Role of historical documentation, instrumentation data, and visual information in forensic evaluations

Effects of bonding on tailings mechanical behavior and its impact on numerical modelling

Advancements on CPT analyses of tailings materials

Root-cause analyses considerations

The participants will learn:

Why the Feijao Dam failed when it did

Applicability of monitoring and instrumentation strategies to tailings dams

Best practices for numerical analyses of bonded materials

Applicability of CPT to bonded tailings

Lucas de Melo

Senior Principal Geotechnical Engineer

Geosyntec Consultants and The Johns Hopkins University

Lucas de Melo has over 25 years of experience in mining and dam-related projects, geotechnical design and field studies, hazardous materials remediation, and solid waste management facilities. His portfolio of clients includes public and private entities. Lucas was part of the four-member Expert Panel tasked to investigate the failure of the Feijão Tailings dam in Brazil in 2019. He currently serves as a Dams and Mining practice leader at Geosyntec’s Columbia, Maryland office, working on risk quantification, engineering evaluation, and design of rehabilitation projects and new facilities. In addition, Dr. de Melo is responsible for the geotechnical curriculum at the Johns Hopkins University (his alma mater), where he acts as a Lecturer.

Peter K. Robertson

Geotechnical Consultant

PK Robertson Inc

Dr. Peter Robertson has more than 40 years of 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. He is the co-author of the primary reference book on Cone Penetration Testing (CPT). Peter has also assisted in the development of several inexpensive CPT-based interpretation software programs and has presented a series of free webinars in an effort to enhance education and practice. Peter was the Chair of the Expert Panel to investigate the failure of the Feijao Tailing dam failure in Brazil in 2019. Peter continues to provide private consulting to a wide range of clients and currently resides in southern California.