Tailings Dam Failures: A Historical Analysis of the Risk

The number of great magnitude tailings dam collapses has made society increasingly aware of the need to better understand the risk associated with tailings dams' collapse. Also, the analysis and studies of prior disasters should define the risk profiles and lead to the adoption of more adequate and successful policies and measures to reduce hazards. For this, we evaluated the material post-failure behavior, the construction methods, the failure causes and the geographical distribution of tailings dams' failures worldwide. The post-failure behavior was evaluated by the occurrence or absence of flow sliding recorded after the collapse. The historical risks were analyzed by the F-N curve. It was thus possible to better understand these structures' safety historically, as well as to analyze their relationship with the material's behavior. The statistics indicate the correlation between flow behavior and the event consequences. A correlation was also observed deriving from upstream failures, certain materials, some causes of failure and flow sliding. The F-N charts analysis remarks that the unsafety of tailings dams is due to upstream dams since other construction methods present risks under acceptable ranges.