12.1 Dimensions of Failures
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• alterations of the perceived environment (for example, change of colours), even
if they bear no measurable consequences;
• lack of communication;
• lack of empathy and care.
Reputational damages may lead to crises of various types and depth (cost), legal proceedings and consequences, and ultimately suspensions of licenses, business interruption, etc. The areas of the environment reportedly more prone to generating these
damages are:
• highways,
• residential quarters,
• water courses receiving mine outflows (including accidental ones).
Table 12.1 depicts an example from a real-life study, not a general rule. It defines
the potential consequences evolution from minor to ultimate for each consequence
dimension.
12.2 Dam Breach Consequences
As Table 12.1 shows, various mechanisms will lead to the possible ultimate failure,
i.e., a dam breach. The consequence assessment is therefore a critical component of
carrying out a TSF risk assessment.
Unfortunately, there is a great deal of uncertainty in assessing a TSF failure and
it is not possible to produce a definitive deterministic analysis. Consequently these
studies oftentimes include a sensitivity analysis of hypothetical failures that would
produce a range of possible consequences that can be used in a risk assessment.
However, that is not sufficient.
A preliminary analysis of potential dam breach mechanisms may conclude, for
example, that the following three failure mechanisms form the basis for assessment
of a tailings outflow model study:
• Flood-induced over-topping (rainy day scenario);
• Slope-instability-induced over-topping (sunny day scenario);
• Piping failure (sunny day scenario).
In addition to the three failure mechanisms the uncertainty related to tailings
rheology and their flow properties should be incorporated in the outflow model. Three
scenarios for each of the three failure modes can then be assumed, for example, with
the following characteristics:
• Tailings flow is a Newtonian fluid (water);
• Tailings flow is a Bingham fluid with average rheological properties;
• Tailing is a Bingham fluid with a high concentration of solids.
171
• alterations of the perceived environment (for example, change of colours), even
if they bear no measurable consequences;
• lack of communication;
• lack of empathy and care.
Reputational damages may lead to crises of various types and depth (cost), legal proceedings and consequences, and ultimately suspensions of licenses, business interruption, etc. The areas of the environment reportedly more prone to generating these
damages are:
• highways,
• residential quarters,
• water courses receiving mine outflows (including accidental ones).
Table 12.1 depicts an example from a real-life study, not a general rule. It defines
the potential consequences evolution from minor to ultimate for each consequence
dimension.
12.2 Dam Breach Consequences
As Table 12.1 shows, various mechanisms will lead to the possible ultimate failure,
i.e., a dam breach. The consequence assessment is therefore a critical component of
carrying out a TSF risk assessment.
Unfortunately, there is a great deal of uncertainty in assessing a TSF failure and
it is not possible to produce a definitive deterministic analysis. Consequently these
studies oftentimes include a sensitivity analysis of hypothetical failures that would
produce a range of possible consequences that can be used in a risk assessment.
However, that is not sufficient.
A preliminary analysis of potential dam breach mechanisms may conclude, for
example, that the following three failure mechanisms form the basis for assessment
of a tailings outflow model study:
• Flood-induced over-topping (rainy day scenario);
• Slope-instability-induced over-topping (sunny day scenario);
• Piping failure (sunny day scenario).
In addition to the three failure mechanisms the uncertainty related to tailings
rheology and their flow properties should be incorporated in the outflow model. Three
scenarios for each of the three failure modes can then be assumed, for example, with
the following characteristics:
• Tailings flow is a Newtonian fluid (water);
• Tailings flow is a Bingham fluid with average rheological properties;
• Tailing is a Bingham fluid with a high concentration of solids.