15.1 Portfolio Description
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15.1.2 Interdependencies of the Dams
There is an external interdependency between Dam 2 and Dam 3 insofar as a failure
of Dam 2 would provoke an erosion at the toe of Dam 3, as we will describe later.
Furthermore, Dam 3 has internal interdependencies due to possible local failures
of raises.
15.1.3 Ancillary Structures and Other Dam Conditions
There are no penstocks systems in the portfolio’s dams, except for Dam 4.
There are tailings pipelines at the crest of Dams 1A, 1B and 3 while Dam 4 is in
the process of deactivation, thus there is no active spigotting at its crest.
There are vehicular and subcontractor traffic at the crest of all dams.
15.1.4 Scheme of the System
The “map” of the system is schematically displayed in Fig. 15.5. The map helps
to define the boundaries of the dam systems and the overarching portfolio (see
Sect. 8.2.2). However, the map is a symbolic one, with no scale. Tailings are depicted
in grey; the water of pond 2 and watercourses in blue; valleys bottoms are white; and
major residential and industrial structures are displayed as orange rectangles. Roads
appear as single black lines, whereas a railroad, in a dotted line, crosses the map
from east to west in the south of the map.
The map has the objective of allowing a preliminary estimate of potential consequences by looking at the land use downstream of each dam. The level of details
is variable: the more potential targets of high value, the higher the detail in order to
enable consequence evaluations. It is very important to focus on the consequences,
as engineering analyses oftentimes focus on the hazard side of the risk equation and
neglect the consequence side (Eq. 1.1).
15.1.5 Geotechnical Conditions as Reported by Engineering
Reports
The geotechnical materials for Dams 1A and 1B are defined in Table 15.1.
The geotechnical materials for Dam 2 are defined in Table 15.2.
The geotechnical materials for Dam 3 are defined in Table 15.3.
223
15.1.2 Interdependencies of the Dams
There is an external interdependency between Dam 2 and Dam 3 insofar as a failure
of Dam 2 would provoke an erosion at the toe of Dam 3, as we will describe later.
Furthermore, Dam 3 has internal interdependencies due to possible local failures
of raises.
15.1.3 Ancillary Structures and Other Dam Conditions
There are no penstocks systems in the portfolio’s dams, except for Dam 4.
There are tailings pipelines at the crest of Dams 1A, 1B and 3 while Dam 4 is in
the process of deactivation, thus there is no active spigotting at its crest.
There are vehicular and subcontractor traffic at the crest of all dams.
15.1.4 Scheme of the System
The “map” of the system is schematically displayed in Fig. 15.5. The map helps
to define the boundaries of the dam systems and the overarching portfolio (see
Sect. 8.2.2). However, the map is a symbolic one, with no scale. Tailings are depicted
in grey; the water of pond 2 and watercourses in blue; valleys bottoms are white; and
major residential and industrial structures are displayed as orange rectangles. Roads
appear as single black lines, whereas a railroad, in a dotted line, crosses the map
from east to west in the south of the map.
The map has the objective of allowing a preliminary estimate of potential consequences by looking at the land use downstream of each dam. The level of details
is variable: the more potential targets of high value, the higher the detail in order to
enable consequence evaluations. It is very important to focus on the consequences,
as engineering analyses oftentimes focus on the hazard side of the risk equation and
neglect the consequence side (Eq. 1.1).
15.1.5 Geotechnical Conditions as Reported by Engineering
Reports
The geotechnical materials for Dams 1A and 1B are defined in Table 15.1.
The geotechnical materials for Dam 2 are defined in Table 15.2.
The geotechnical materials for Dam 3 are defined in Table 15.3.