The Next Generation of Seismic Vulnerability Analysis€¦ · 01-06-2019 · Pacific Northwest...
Transcript of The Next Generation of Seismic Vulnerability Analysis€¦ · 01-06-2019 · Pacific Northwest...
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The Next Generation of Seismic Vulnerability AnalysisBellevue’s Iterative, Probabilistic, Risk-Based Evaluation
May 3, 2019 – Doug Lane, PE, and Matt Maring, PE
Presentation Overview
• Safety Moment
• Project Approach Overview
• Bellevue Water System Overview
• Seismic Risks and Threats
• Geotechnical Seismic Analysis
• Evaluation Approaches and Progress
• Next Steps
2
Safety Moment – Earthquake Self Protection
3
Project Approach Overview
Project Goals and Priorities
Characterize water system seismic threats
Identify vulnerabilities and potential customer impacts
Determine improvements needed to mitigate risks
Develop level of service goals and implementation plans
5
Seismic Vulnerability Assessment Approach
Prioritize
Improvements
Establish
(Revisit)
LOS Goals
Identify and
Evaluate
Improvements
Restoration
and Economic
Analysis
Customer
Impacts
Existing
System
Vulnerability
Geotechnical and
Seismic Data
Evaluation
Criteria and
Methodology
Data Collection
and Review
Project
Chartering
6
Bellevue Water System Overview
Bellevue Water Service Area
• 150,000+ Population
• 140,000+ Jobs
• 13 Regional Water
Supply Inlet Stations
• 69 Pressure Zones
• 24 Storage Tanks
• 22 Pump Stations
• 148 PRV Stations
• 620 Miles of Pipe
• 20-1440 ft Surface
Elevations
8
Bellevue Water System Hydraulic Profile
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Seattle Public Utilities Regional Supply System
• Cedar and Tolt River
Surface Water Supplies
• Cedar Eastside Supply Line
• Tolt Eastside Supply Line
• Wholesale water supply to
Bellevue and other regional
retail supply systems
10
Seismic Risks and Threats
Pacific Northwest Faults and Bellevue Risks
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• Cascadia
Subduction
Zone (CSZ)
• Seattle
Fault
Zone (SFZ)
• South
Whidbey
Island
Fault (SWIF)
Cascadia Subduction Zone Earthquake
• “The Big One”
• Magnitude 9.0
• ~500 year event
• Longer (~3 minutes) duration
• Pacific Ocean epicenter
• Broad regional impacts
(U.S. Geological Survey)
13
Seattle Fault Zone Earthquakes
• The actual “Big One”?
• Magnitude 6.6 (800+ year) to
Magnitude 7.2 (4,000+ year)
• Short duration
• Shallow fault
• Epicenter near or
under Bellevue
• Severe localized
impacts
14
Geotechnical Seismic Analysis
Peak Ground Acceleration (PGA)
Cascadia Subduction Zone
Mw 9.0
Seattle Fault Zone East
Mw 6.6
16
Liquefaction and Subsidence Risks
Cascadia Subduction Zone
Mw 9.0
Seattle Fault Zone East
Mw 6.6
17
Landslide and Slope Stability Risks
Cascadia Subduction Zone
Mw 9.0
Seattle Fault Zone East
Mw 6.6
18
Evaluation Approach and
Progress
Facility Hazus Vulnerability Analysis
20
Compare current facility to code requirements
Select Hazus fragility curve corresponding to “code level”
Overlay predicted seismic ground motions
Evaluate damage probabilities based for use in multi-break modeling analysis
Facility Hazus Vulnerability Analysis
21
Pipeline ALA Vulnerability Analysis
22
Identify location, material, and size of pipes via GIS
Apply appropriate ALA fragility equation based on pipe classification
Overlay predicted seismic ground motion and displacement
Evaluate leak and break probability for use in multi-break modeling analysis
Pipeline ALA Vulnerability Analysis
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Permanent Ground Deformation (inches)
Probability of Failure of DI Pipe
Leaks and Breaks per 1,000ft Probability of Failure of 100 ft pipeline
Seattle Fault Zone East – Pipe Failure Distribution
Probable Pipe Break Counts
by Analysis Area
Combined Probable Pipe Breaks and
Leak Counts by Analysis Area
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Seattle Fault Zone East – Pipe Failure Probabilities
Pipe Leak
Probabilities
Pipe Break
Probabilities
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Single Pipe Failure and Criticality Analysis
Number of Valve Closures Required
for Pipe Failure Isolation
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Single Pipe Failure and Criticality Analysis
Demands Supplied below 30 psi
during Pipe Breaks Events
27
Single Pipe Failure and Criticality Analysis
Demands Supplied Below 30 psi
during Pipe Break Isolation
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Monte Carlo Scenario Development and Modeling
Model Scenario Development
Hydraulic Model
Scenarios Analysis
Service Impacts
and Trends
29
Monte Carlo Simulation Development
Methodology
• Custom Python script developed
to simulate scenarios
• Pipe breaks and leaks based on
ALA probability of occurrence
• Facility status based on probability
of damage from Hazus
• 10,000 simulations for use in
multi-break modeling analysis with
Optimatics
• Compared damage results to
mean expected values by system
subarea to confirm results are
“helpful”
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Next Steps
Next Steps
• Multiple Break and Failure Impacts Analysis and Results
(All Elements, Iterative, Probabilistic, Monte Carlo Model Evaluations)
• Projected Customer and Economic Impacts
• Restoration Strategies and Service Recovery
• Improvement Alternatives and Benefits Analysis
• Levels of Service
and Cost-Benefit
Analysis
• Improvement
Recommendations
and Planning
32
Core Team Acknowledgements
33
City of Bellevue
• Andrew Lee
(now Seattle Public Utilities)
Jacobs
• Don Ballantyne
• Kateryna Gomozova
• Jennifer Henke
• Kimberly Lawrence
• Enoch Nicholson
• Menzer Pehlivan
Shannon and Wilson
• Bill Perkins
• Ali Shahbazian
Optimatics
• Joshua Cantone
Questions and Discussion
www.jacobs.com | worldwideMay 9, 2019
© Copyright Jacobs
The Next Generation of Seismic
Vulnerability AnalysisBellevue’s Iterative, Probabilistic, Risk-Based Evaluation