Embankment Dam and Spillway Relative Risk Procedures (for Asset Management/Maintenance)

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Embankment Dam and Spillway Relative Risk
Procedures (for Asset Management/Maintenance)

• Luc Chouinard McGill University

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Asset Management

• Project Context
• Improve procedures for evaluating the current
  state of assets
• Inspections performed on an annual basis and
  reports filed with government agencies
• Develop objective procedures for ranking
  maintenance priorities
• Limited budgets
• Ranking process must be uniform across all
  administrative units

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• Project Objectives
• Asset Management Strategy for
• Embankment dams
• Spillways
• Concrete dams

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• General principles
• Identification and ranking of maintenance
  interventions.
• Current state is determined from site inspection
  and data from dam/spillway performance
  evaluation reports (component reliability REMR
  scale)
• Importance is based on the contribution of
  various components to dam/spillway performance
  (for system reliability), specific for each
  facility.
• Ranking is established as a function of relative
  importance and current state of dam components

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Asset Management for Embankment Dams

• Initiated in 1995 (Hydro-Quebec with USACE)
• Tested by Hydro-Quebec in 1999 on 25 dams
• Application Guide developed in 2000 by
  Hydro-Quebec (reduce uncertainty)
• Gradually introduced in all districts
• Adopted by Manitoba-Hydro and Cemagref (France)

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Methodology
Failure Modes
A
Evaluation of Relative Probabilities
Adverse Conditions
Adverse Condition Indicators
B Importance Evaluation
Defense Groups
Monitoring Activities and Devices
C Condition Evaluation
Condition of Monitoring Activities and Devices
Condition of Defense Groups
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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ADVERSE CONDITIONS AND FAILURE MODES
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Failure Modes (4)
A
Evaluation of relative probabilities
A RULES
Adverse Conditions AC1 to AC7
TABLE 2.8
Adverse Condition Indicators
Defense Groups DG1 to DG8
B Importance Evaluation
Monitoring Activities and Devices
C Condition Evaluation
Condition of Monitoring Activities and Devices
Relationship to set up
Condition of Defense Groups
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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Failure Modes (4)
A
Evaluation of relative probabilities
A RULES
Adverse Conditions AC1 to AC7
TABLE 2.8
Adverse Condition Indicators
Defense Groups DG1 to DG8
B Importance Evaluation
Monitoring Activities and Devices
TABLES 2.12 to 2.19
C Condition Evaluation
Condition of Monitoring Activities and Devices
Relationship to set up
Condition of Defense Groups
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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REMR Scale
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• Condition Table for a Defense Group
• Define its function (performance based)
• Define what is an excellent condition (100)
• Define what is a failed condition (0)
• Identify indicators of condition
• Physical measurement
• Performance level
• Qualitative observation

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Pressure control in foundation
Upstream slope protection
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Failure Modes (4)
OBSERVATION QUALITY
DATA INTERPRETATION
A Subjective Evaluationof Risk
B RULES
A RULES
Adverse Conditions AC1 to AC7
TABLE 3.2
TABLE 2.8
Adverse Condition Indicators AC IND1 to IND12
Defense Groups DG1 to DG8
B Importance Evaluation
Monitoring Activities and Devices
TABLES 2.12 to 2.19
C Condition Evaluation
Condition of Monitoring Activities and Devices
Relationship to set up
Condition of Defense Groups
TABLE 2.20
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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Deformation
Seepage
Pressure
Vegetation
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Failure Modes (4)
OBSERVATION QUALITY
DATA INTERPRETATION
A Subjective Evaluationof Risk
B RULES
A RULES
Adverse Conditions AC1 to AC7
TABLE 3.2
TABLE 2.8
Adverse Condition Indicators AC IND1 to IND12
Defense Groups DG1 to DG8
B Importance Evaluation
C RULES TABLE 3.4
Monitoring Activities and Devices MD1 to MD14
TABLES 2.12 to 2.19
TABLE 3.5
C Condition Evaluation
Condition of Monitoring Activities and Devices
Relationship to set up
Condition of Defense Groups
TABLE 2.20
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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Asset Management
Failure Modes (4)
OBSERVATION QUALITY
DATA INTERPRETATION
A Subjective Evaluationof Risk
B RULES
A RULES
Adverse Conditions AC1 to AC7
TABLE 3.2
TABLE 2.8
Adverse Condition Indicators AC IND1 to IND12
Defense Groups DG1 to DG8
B Importance Evaluation
C RULES TABLE 3.4
Monitoring Activities and Devices MD1 to MD14
TABLES 2.12 to 2.19
TABLE 3.5
C Condition Evaluation
Condition of Monitoring Activities and Devices
Relationship to set up
Condition of Defense Groups
TABLE 3.6
TABLE 2.20
D Priority ranking
Monitoring Activities Priorization Monitoring
Devices Maintenance
Defense Group Maintenance
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Proposed new instruments
Visual inspections
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• Spillways

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• Partners
• U.S. Army Corps of Engineers
• Manitoba Hydro
• Ontario Power Generation
• U.S. Bureau of Reclamation
• Hydro-Québec
• McGill University

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• Importance Factors
• Conceptual model of the spillway (number of
  gates, lifting devices, etc.)
• Identify major functional issues associated with
  the spillway
• Relative importance of components for each
  function (factors considered role of the
  component,response time, reaction,)

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• Step 2

For navigation, recreation, water supply,etc.
Control water levels
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Spillway
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Spillway
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Évacuateur
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Spillway
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• Conclusions
• Priority ranking identifies most advantageous
  maintenance activities in terms of dam safety
• Method permits good overview of dam condition and
  behavior
• Values Dam Safety Engineer technical judgment
• Uniform procedure
• Flexible and adaptable

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Thank you!