BRIDGE PERFORMANCE:

Benchmarking the Performance of California BridgesBozidar StojadinovicKevin MackieJohn-Michael WongAdy AviramVesna Terzic

University of California, Berkeley

PEER Bridge Performance ProgramFocus on:

Monolithic reinforced concrete construction New rather than older construction detailing

Representative of typical: Over-crossingsViaductsInterchanges

Also…Ground motions and their use in analysis and designSoil-foundation interactionSimulation of complex bridge systemsTransportation networks

OutlinePerformance benchmarking for a baseline testbed bridge suite is donePracticing bridge engineers can use our work: Hazard modeling Non-linear bridge models Fragility curves PEER frameworkRational uses of new technologies for bridges are devised and evaluated

PEER Testbed Bridges5-span RC overpasses (Ketchum, 2004)

Type 1 Type 11

PEER Framework for Bridge Evaluation

Engineering Demand Parameter (EDP)

Inte

nsit

y M

easu

re (

IM)

Engineering Demand Parameter (EDP)

Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Variable (DV)Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Model

Damage Model

Demand Model

Hazard Model

0 . 1 1 1 0 1 0 0 1 0 0 0Distance (km )

4

5

6

7

8

Magn

itude

0 . 1 1 1 0 1 0 0 1 0 0 0Distance (km )

4

5

6

7

8

Magn

itude

Select and scale ground motions

PEER Framework for Bridge Evaluation

Engineering Demand Parameter (EDP)

Inte

nsit

y M

easu

re (

IM)

Engineering Demand Parameter (EDP)

Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Variable (DV)Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Model

Damage Model

Demand Model

Hazard Model

CL

Do non-linear time-history

analyses

PEER Framework for Bridge Evaluation

Engineering Demand Parameter (EDP)

Inte

nsit

y M

easu

re (

IM)

Engineering Demand Parameter (EDP)

Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Variable (DV)Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Model

Damage Model

Demand Model

Hazard Model Performance(damage)

states

PEER Framework for Bridge Evaluation

Engineering Demand Parameter (EDP)

Inte

nsit

y M

easu

re (

IM)

Engineering Demand Parameter (EDP)

Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Variable (DV)Dam

age

Mea

sure

(D

M)

discrete

continuous

Decision Model

Damage Model

Demand Model

Hazard Model DeathsDollars

Down-time

Outcome: Repair cost ratio

fragility curves

PEER Framework for Bridge Evaluation

Demand Model

Sa(T1)=1g

The Practice of Hazard Modeling

175 worldwide earthquakes>10,000 corrected records with detailed descriptorsEstimate ground motion intensity and uncertainty of the estimateGround motion scaling rules

Next-Generation Attenuation Relationshttp://peer.berkeley.edu/nga

1 10 100Horizontal Distance to Fault (km)

10-2

10-1

100

Acc

eler

atio

n (g

)

PGA

Campbell & Bozorgnia (2003)Campbell & Bozorgnia (Prelim NGA)

PARAMETERS: M = 6.5, 7.0, 7.5, 8.0 Fault = Strike Slip Dip = 90 Vs30 = 600 (C)

0 . 1 1 1 0 1 0 0 1 0 0 0Distance (km )

4

5

6

7

8

Magn

itude

0 . 1 1 1 0 1 0 0 1 0 0 0Distance (km )

4

5

6

7

8

Magn

itude

Old DataNew Data

The Practice of Bridge Modeling

Core

Foundation

Deck

Column

Abutment

Modular OpenSees model

The Practice of Bridge ModelingUsing SAP 2000

NL Option Pushover Analysis

(Static 2D)

45o Pushover (Static 3D)

THA-L,V or T,V components

(Dynamic 2D)

THA-L,T,V components

(Dynamic 3D)Uncoupled Hinge M2,M3

X*

Interaction PMM Hinge

X* X*

Fiber PMM Hinge X* X* X* X*NL-link- Plastic Wen X* X*NL-link- Multi-Linear Plastic

X* X*

Displacement Time History- Longitudinal

-10

-7.5

-5

-2.5

0

2.5

5

7.5

10

12.5

15

17.5

0 5 10 15 20 25 30 35 40 45

t- Time (sec)

D- C

ol to

p di

spla

cem

ent (

in)

OS-NLSAP-WenSAP-FiberSAP-MLP

The Practice of Damage EvaluationPEER Structural Performance Databasehttp://nisee.berkeley.edu/spd/index.html

Type 1

Type 11

The Practice of Decision Support

DS1: CrackingInject cracks (200 LF)Repair minor spalls (10 SF)

DS3: Bar BucklingInject cracks (200 LF)Repair minor spalls (236 SF)Steel column casing (50 LF)Bridge bar reinforcement (1562 KG)

DS2: SpallingInject cracks (200 LF)Repair minor spalls (94 SF)

DS4: FailureReplace column (6728 SF)

Column Damage States

$ 13 SFRefinish bridge deckQ13$ 200 CYRemove and replace approach roadwayQ12$ 30 SFRemove and replace approach slabQ11$ 2,000 EAReplace abutment shear keyQ10$ 1,000 LFReplace abutment back wallQ9$ 3,000 EAReplace elastomeric bearingQ8$ 900 LFReplace joint seal assembliesQ7$ 90 LFReplace joint sealsQ6$ 2 KGBridge bar reinforcementQ5$ 2,000 LFSteel column casingQ4$ 100 SFRepair minor spallsQ3$ 80 LFInject cracks with epoxyQ2$ 120 SFReplace columnQ1

Unit Cost

UnitRepair Item DescriptionItem No.

$ 13 SFRefinish bridge deckQ13$ 200 CYRemove and replace approach roadwayQ12$ 30 SFRemove and replace approach slabQ11$ 2,000 EAReplace abutment shear keyQ10$ 1,000 LFReplace abutment back wallQ9$ 3,000 EAReplace elastomeric bearingQ8$ 900 LFReplace joint seal assembliesQ7$ 90 LFReplace joint sealsQ6$ 2 KGBridge bar reinforcementQ5$ 2,000 LFSteel column casingQ4$ 100 SFRepair minor spallsQ3$ 80 LFInject cracks with epoxyQ2$ 120 SFReplace columnQ1

Unit Cost

UnitRepair Item DescriptionItem No.

Damage StatesRepair Quantities

Repair Costs

Performance Groups and EDPsColumns

Tangential drift ratio SRSS

Expansion JointsLong. abutment displacement

BearingsBearing displacement

Back WallsBack wall displacement

Shear KeysShear key force

Approach SlabsVertical abutment settlement

Deck SegmentsDepth of spalling

ColumnsTangential drift ratio SRSS

Performance Groups and EDPsColumns

Tangential drift ratio SRSS

Expansion JointsLong. abutment displacement

BearingsBearing displacement

Back WallsBack wall displacement

Shear KeysShear key force

Approach SlabsVertical abutment settlement

Deck SegmentsDepth of spalling

ColumnsTangential drift ratio SRSS

Performance Groups

Matlab tool:Given:

Demand, damage, loss models (with uncertainties)

Numerous assumptions

integrate the PEER integralEasy visualization of results

Decision fragility Decision hazard

A Practical Implementation

Advances: Non-linear SFS Models

Coupled Soil-Foundation-Structure modelEffects of liquefaction and lateral spreading

UCB+UW team

Advances: Enhancing Performance Rational use of new

technologies:Re-centering columns Tendons Isolators

New high-performance materials: HPFRCC

Modular construction Precast, prestressed elements

0.00.51.01.52.02.5

0.00 0.01 0.02 0.03 0.04Tensile Strain

Tens

ile S

tres

s (M

Pa)

HPFRCC

Mortar FRC

Advances: Regional Traffic Networks

RegionalShake Map

Bridge Fragility Curves

Regional TrafficNetwork Assessment

ConclusionPerformance benchmarking for a baseline testbed bridge suite is donePracticing bridge engineers can use our work: Hazard modeling Non-linear bridge models Fragility curves PEER framework

Rational uses of new technologies for bridges are devised and evaluated

Attend Bridge breakout sessions to learn more!

Thank You! HazardHazard

DemandDemand

DamageDamage

LossLoss

For more information:boza@ce.berkeley.edukmackie@mail.ucf.edu

This research was sponsored in part by NSF EERC program grant EEC-9701568 as PEER Project 209/213