Tailings Storage Facilities (TSFs) are a major component of mining infrastructure, where the waste product of the mining process (tailings) is stored. A breach of such a facility would result in destructive, oftentimes toxic, tailings flows over a substantial distance downstream of the TSF. More than 63 major tailings dam failures were recorded worldwide. in the last 50 years, thereby establishing a failure rate which is several times higher than that of water-retaining dams. Understanding and predicting the tailings flow path should a TSF failure occur is critical to the design process pf a safe TSF. A hypothetical analysis of these flows is referred to as a Tailings Dam Breach Analysis (TDBA). These analyses typically follow guidelines set out for water-retaining dams with some adaptations to account for the critical non-Newtonian properties of a tailings flow. Following the tragic failure of the TSF at the Feijao mine in Brazil, and as of August 2020, conducting a TDBA has become a requirement of the Global Industry Standards for Tailings Management (GISTM) for all TSF's.
A commonly used software for modelling a non- Newtonian breach flood is FLO-2D. FLO-2D is a flood routing model created in 1986 for the purpose predicting mudflow hydraulics and is supported by the US Federal Emergency Management Agency. The software allows for the geotechnical properties of a tailings flow (rheology and sediment concentration) to be modelled.
In the most recent release of the popular water flow modelling software, Hydrologic Engineering Center's River Analysis System (HEC-RAS), the software's capabilities have been extended to include non-Newtonian flow modelling. This allows the flood-routing model to be used as a TDBA tool. HEC-RAS was designed by the US Army Corps of Engineers, and is universally available at no cost to the user. The software has been widely used to perform one-dimensional steady flow and one and two-dimensional unsteady flow simulations involving hydraulic structures.
