PEER Bridge Testbed: Findings and Research Needs

1
PEER Bridge Testbed Findings and Research Needs

• Bozidar Stojadinovic, Professor
• UC Berkeley

2
PEER Bridge Testbed
3
PEER Framework for Bridge Evaluation
Hazard Model
The framework has 4 components
Demand Model
Damage Model
Decision Model
4
PEER Framework Hazard Model
Hazard Model
Hazard curve developed using old attenuation
relations
Demand Model
Damage Model
Decision Model
5
PEER Framework Hazard Model
Hazard Model
Select and scale ground motions
Demand Model
Damage Model
Decision Model
6
PEER Framework Demand Model
Do non-linear time-history analyses
Hazard Model
Demand Model
Damage Model
Decision Model
7
PEER Framework Demand Model
Developed new bridge modeling guidelines
Hazard Model
Demand Model
Damage Model
Decision Model
8
PEER Framework Demand Model
Hazard Model
Demand Model
Damage Model
Decision Model
9
PEER Framework Damage Model
Performance (damage) states
Hazard Model
Demand Model
Damage Model
Decision Model
10
PEER Framework Damage Model
Hazard Model
Demand Model
Decision Model
Damage Model
11
PEER Framework Decision Model
Hazard Model
Deaths Dollars Down-time.
Demand Model
Damage Model
Decision Model
12
Decision Variable Repair Cost Ratio
Performance Groups
Damage States Repair Quantities
Repair Costs
13
PEER Framework Decision Model
Hazard Model
Demand Model
Damage Model
Decision Model
14
PEER Framework Outcome
Hazard Model
Demand Model
Damage Model
Decision Model
15
PEER Framework Integration

• Scalar
• Vector, closed form (Fourway)
• Vector, linearized damage model

16
PEER Framework RCR Fragility Curves
Conditional probability or exceeding a
performance objective, given hazard intensity
17
PEER Framework RCR Disaggregation
18
Findings and Accomplishments

• PEER framework
• Implemented
• Applied to a testbed bridge
• Damage- and decision-level outcomes in terms of
  fragilities and disaggregation
• Modeling
• Non-linear bridge modeling guidelines
• Data
• Collected and organized bridge damage and
  decision-level data
• Defined performance groups

19
Relevance for Caltrans

• Testbed bridge is similar to Caltrans standard
  ordinary bridges
• Derived fragilities are immediately usable for
  bridge and traffic network state assessment
• Developed bridge modeling guidelines are
  immediately usable by Caltrans engineers
• Reviewed Caltrans damage assessment and repair
  methods basis for systematization and
  improvements of the performance group approach
• Correlation and coordination with FHWA and other
  projects
• Leadership

20
Refinements

• Hazard curves
• NGA project data
• Ground motion selection
• Vertical acceleration and coherence
• Other hazards
• Bridge component models
• Calibration
• Abutments (behavior and modeling)
• Joints
• Bridge system models
• Validation (instrumented testbed)
• Other standard ordinary bridges (multi-column
  bents, irregularities such as skewed, curved,
  unequal-height columns)
• Post-event live-load capacity

21
Refinements

• Damage states
• Damage database
• Calibration, for all components/performance
  groups
• Calibration at the system level
• Continuous vs. discrete
• Decisions
• Repair method database
• Refinement of performance group approach in
  accordance with lean construction management
  efforts
• Refinement of repair methods to obtain better
  (continuously updated) cost estimates and repair
  time estimates
• Refinement of post-event capacity models
• Deployment of fragility data in system-level and
  bridge-level evaluation

22
Knowledge Breakthroughs

• Next-Generation Bridges
• Seismic Accelerated Bridge Construction
• Advanced technologies for enhanced performance
• Base isolation
• Rocking
• Sensors
• Lean delivery
• Sustainable construction technologies
• Seismic worthiness
• Performance-based design and evaluation

23
Thank You!
Demand
Hazard
Loss
For more informationboza_at_ce.berkeley.edu
Damage
This research was sponsored in part by NSF EERC
program grant EEC-9701568 as PEER Projects 209,
213 and 244