8.2 Physical System Definition
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Fig. 8.6 A long tailings and decant pipelines between the mill and the TSF
Example B: A Long Tailings Pipeline Between the Mill and the TSF
The next example (Fig. 8.6) focuses on the pipelines. In this example we show tailings
main and decant water, but modern mines have many other pipelines, including those
for water, sea-water, and concentrates. How many sub-elements do we need to define
for each pipe? Mining pipelines around the world display a huge variety of lengths,
from hundreds of metres to over 100 km.
Pipelines have to be split in “homogeneous sections” as a function of their conditions (slopes, geology), environment (land use, topography, containment) and special
characteristics (tunnels, river crossings, siphons, sharp bends, etc.). Potential traffic
hits and fires (natural forest/brush, access) have also to be considered when splitting
a pipeline into homogeneous sections.
Example C: One TSF with Diversion Ditch and Tailings Distribution Line
Figure 8.7 shows a real-life tailings pond created by a dam (sector V) and protected
by a storm water diversion channel. The main tailings lines are very short, from the
mill pumps to the beginning of the peripheral tailings distribution line. For the sake
of the risk assessment it was necessary to split the tailings distribution line into six
segments, numbered I to VI.
The rationale is to have segments that are “homogeneous” in terms of hazards
and/or consequences. Hence, for example, Segment I could be hit by a diversion
failure and the flooding would “immediately” report to the abutment of the dam
(possible wash-out area), generating an inter-dependent failure potential. Segment
II would, in contrast, possibly be hit by the diversion ditch failure, but the flooding
would report to the pond centre. Segment V on top of the dam could erode the dam
and wreak havoc on the structure crest, etc.
8.3 A Note on Inter-Dependencies
We just mentioned inter-dependencies again, so it is a good time to discuss this aspect
a bit further. Inter-dependencies are often present even within a single dam crosssection. In this case they are called “internal inter-dependencies”. Inter-dependencies
are also known as “domino effects”.
113
Fig. 8.6 A long tailings and decant pipelines between the mill and the TSF
Example B: A Long Tailings Pipeline Between the Mill and the TSF
The next example (Fig. 8.6) focuses on the pipelines. In this example we show tailings
main and decant water, but modern mines have many other pipelines, including those
for water, sea-water, and concentrates. How many sub-elements do we need to define
for each pipe? Mining pipelines around the world display a huge variety of lengths,
from hundreds of metres to over 100 km.
Pipelines have to be split in “homogeneous sections” as a function of their conditions (slopes, geology), environment (land use, topography, containment) and special
characteristics (tunnels, river crossings, siphons, sharp bends, etc.). Potential traffic
hits and fires (natural forest/brush, access) have also to be considered when splitting
a pipeline into homogeneous sections.
Example C: One TSF with Diversion Ditch and Tailings Distribution Line
Figure 8.7 shows a real-life tailings pond created by a dam (sector V) and protected
by a storm water diversion channel. The main tailings lines are very short, from the
mill pumps to the beginning of the peripheral tailings distribution line. For the sake
of the risk assessment it was necessary to split the tailings distribution line into six
segments, numbered I to VI.
The rationale is to have segments that are “homogeneous” in terms of hazards
and/or consequences. Hence, for example, Segment I could be hit by a diversion
failure and the flooding would “immediately” report to the abutment of the dam
(possible wash-out area), generating an inter-dependent failure potential. Segment
II would, in contrast, possibly be hit by the diversion ditch failure, but the flooding
would report to the pond centre. Segment V on top of the dam could erode the dam
and wreak havoc on the structure crest, etc.
8.3 A Note on Inter-Dependencies
We just mentioned inter-dependencies again, so it is a good time to discuss this aspect
a bit further. Inter-dependencies are often present even within a single dam crosssection. In this case they are called “internal inter-dependencies”. Inter-dependencies
are also known as “domino effects”.