ORE2 tailings technical explanations
Sep 8th, 2021
The first ORE2_Tailings™ deployment for a given client and selected TSF portfolio is an a priori endeavor insofar it delivers estimates that require calibration and adaptation as new data and new events will occur. In particular, this report will require amendments and updates when, for example, new Space Observation (satellite) or other monitoring results, corrective actions reports, changes in service conditions, new incidents reports and inspections may become available.
ORE2 tailings technical explanations: Diagnostic poins
ORE2_Tailings™ is a subset of the “universal” ORE platform specific to Tailings dams, companion with ORE2_Dams and ORE2_Dykes. ORE2_Tailings™ uses “symptoms” or diagnostic “points” in the history of the dam from inception to the day of the evaluation. In addition it uses data and information related to ancillary water management, pipelines, water balance and traffic at the crest delivered to Riskope. Thus ORE2_Tailings™ is compliant with the GISTM and its conformance protocol. The approximately forty diagnostic “points” are KPIs (Key Performance Indicators)/or KRIs (Key Risk Indicators). ORE2_Tailings™ combines them with:
- the results of engineering analyses (Factor of Safety, settlements, liquefaction),
- information drawn from the history of the structure since inception and, if
- available, Space Observation results.
Depending on the mandate, travel restrictions, quality of the archival documents and goal of the study, site inspections may be postponed to a later date. Thus, if the client desires, it is possible to perform a first round of a priori prioritization using archival data and available imagery. Of course, the level of uncertainty of such a study will be larger than if more data and site visits would be performed. However, given that the goal is to perform a prioritization of relative risks, a client may deem such an approach sufficient as a first step.
The evaluations of the KPIs/KRIs are mathematically combined in the risk analysis. Consequences of a failure and its probabilities generate the risk evaluation, including related uncertainties. Explicit consideration of uncertainties is indeed a fundamental step towards reasonable and defensible risk assessments. ORE2_Tailings™ always considers the dams and their respective (or common in some cases) ancillary water management systems.
ORE2 tailings technical explanations: Causality
The KPIs/KRIs cover the life of the dam system from inception and converge on “families” of causality:
- investigation and material testing;
- construction and finally;
- operations and maintenance (including monitoring).
Causality analysis can be paramount in guiding mitigative decision-making.
The figure below conceptually displays the:
- combination of the KPIs in the four aggregated causality families,
- probability of failure, consequences and finally,
As visible in the illustration above, the probability of failure resulting from the composition of the KPIs evolves all along the dam life while it maintains a certain level of uncertainties.
Tagged with: dam risk analysis, Diagnostic poins, tailings, Tailings Dam failure, tailings dams causality, TSF portfolio
Category: Consequences, Hazard, Mitigations, Optimum Risk Estimates, ORE2_Tailings, Probabilities, Risk analysis, Risk management