226
15 Risk-Informed Decision Making
This will avoid our falling in the trap of characterising as “safe” dams that have
a probability of failure well in the range of credibility.
15.3 Conditions from Inception to the Date of Analysis
of the Dams (Physical and Governance)
In this section we summarize the conditions over the known history of the dams, as
has resulted from the reading of extant reports and records. Such a summary could
also result from interviews and other classic means (Sect. 9.1). Should modern hazard
identification and monitoring data (Sect. 9.2) such as space or drone observation history be available, then those results should also be integrated in the dam descriptions.
IoT and other data analyses would also complement this information.
Of course, all the data and interpretations contained herein should be stored (and
retrievable by drills), updated in a portfolio data base (Hazard and Risk Register).
It is obvious that the necessary complexity of the structure of the register records
requires a carefully designed software. This is the reason why we designed the
ORE2_Tailings application (Sect. 14.4).
15.3.1 Dam 1A and Dam 1B
Construction:
• As described above, this is a centerline-rockfill tailings dam analyzed at two stages
(100, 162 m).
• Non-erodable by assumed extreme meteorological conditions.
• Pipeline and traffic at crest.
• Supervision of the dam is excellent in terms of both frequency and the of skills of
the supervisor.
• No geometric divergences have been noted between the plans and the actual structures and minor intermittent seepage is monitored at one location at the toe.
• There are no known errors or omissions in this project, which has been third-party
reviewed by competent independent reviewers.
Geotechnical investigations and testing:
• Boreholes along the dam layout were regular. However, at less than 1/100 m, they
were rather short, barely entering the bedrock.
• No continuous sampling was performed.
• Vane tests and cone tests were numerous but poorly distributed due to limitations
on access.
• Soil classification tests were performed in a reasonable number and at a reasonable
frequency,
15 Risk-Informed Decision Making
This will avoid our falling in the trap of characterising as “safe” dams that have
a probability of failure well in the range of credibility.
15.3 Conditions from Inception to the Date of Analysis
of the Dams (Physical and Governance)
In this section we summarize the conditions over the known history of the dams, as
has resulted from the reading of extant reports and records. Such a summary could
also result from interviews and other classic means (Sect. 9.1). Should modern hazard
identification and monitoring data (Sect. 9.2) such as space or drone observation history be available, then those results should also be integrated in the dam descriptions.
IoT and other data analyses would also complement this information.
Of course, all the data and interpretations contained herein should be stored (and
retrievable by drills), updated in a portfolio data base (Hazard and Risk Register).
It is obvious that the necessary complexity of the structure of the register records
requires a carefully designed software. This is the reason why we designed the
ORE2_Tailings application (Sect. 14.4).
15.3.1 Dam 1A and Dam 1B
Construction:
• As described above, this is a centerline-rockfill tailings dam analyzed at two stages
(100, 162 m).
• Non-erodable by assumed extreme meteorological conditions.
• Pipeline and traffic at crest.
• Supervision of the dam is excellent in terms of both frequency and the of skills of
the supervisor.
• No geometric divergences have been noted between the plans and the actual structures and minor intermittent seepage is monitored at one location at the toe.
• There are no known errors or omissions in this project, which has been third-party
reviewed by competent independent reviewers.
Geotechnical investigations and testing:
• Boreholes along the dam layout were regular. However, at less than 1/100 m, they
were rather short, barely entering the bedrock.
• No continuous sampling was performed.
• Vane tests and cone tests were numerous but poorly distributed due to limitations
on access.
• Soil classification tests were performed in a reasonable number and at a reasonable
frequency,