Seismic Lessons Learned W. Phillip Yen, Ph.D., P.E.SSeismic Research Program ManagerOffice of Infrastructure R&D, FHWA Wen-huei.Yen@fhwa.dot.gov

OutlineSan Fernando, CA 1971Loma Prieta, CA 1989Loma Prieta, CA 1989Northridge, CA, 1994Kobe, Japan, 1995, p ,Kocaeli & Duzce, Turkey, 1999Chi-Chi, Taiwan, 1999Nisqually (Olympia), WA, 2001Niigata, Japan, 2007Pisco, Peru, 2007Concluding Remarks

SAN FERNANDO, CA 1971

SAN FERNANDO

SAN FERNANDO

LESSONS LEARNEDEARTHQUAKE DISASTERSEARTHQUAKE DISASTERS1971 SAN FERNANDO, CA

Increase Seat Width

Provide Continuity at Bearings and Joints

Design Columns for Shear and Moment

Develop Column to Footing/Cap Anchorage

LOMA PRIETA, 1989

LOMA PRIETA

LOMA PRIETA

LOMA PRIETA

THE GEOTECHNICAL E.Q.

Distribution of damageindicated close correlation betweenlocal soil condition and severity of

resultant damage.

LESSONS LEARNED EARTHQUAKE DISASTERSEARTHQUAKE DISASTERS

1989 LOMA PRIETA

Simple retrofit helps

Evaluate Soil/Foundation Stability

Account for Forces/Displacements

Evaluate Existing Inventory

NORTHRIDGE,1994

NORTHRIDGE

NORTHRIDGE

NORTHRIDGE

NORTHRIDGE

NORTHRIDGE

LESSONS LEARNEDEARTHQUAKE DISASTERS

Complex Geometry Redistributes Forces

QU S S S1994 NORTHRIDGE

p y- Skew- Varied Column Heightsg

Accommodate Shear & FlexurePost ‘89 Designs Reduced Damageg gRetrofit Improves Resistance

- Joint Restrainers- Column Jacketing

Preparedness Facilitates Recoveryp y

KOBE, Japan 1995

KOBE

KOBE

LESSONS LEARNEDEARTHQUAKE DISASTERSEARTHQUAKE DISASTERS

1995 HANSHIN AWAJI (KOBE)

Consider Structural Filters /Consider Structural Filters / Fuses

- Isolation

- Energy DissipationEnergy Dissipation

- Displacement Control

LESSONS LEARNED

EARTHQUAKE DISASTERS

Accommodate Forces & DisplacementsEvaluate Ground Motion Amplification/AttenuationEvaluate Ground Motion Amplification/AttenuationConsider “Near Field” EffectsIdentify Liquefaction Potentialy qRetrofit Improves PerformanceCurrent Designs Improve ResistanceP d F ili RPreparedness Facilitates RecoveryNothing is “Earthquake Proof”

The 1999 Turkish Earthquakes: Post-Earthquake Investigation of Structures on TEM

Hamid Ghasemi, PH.D.Philip Yen, PH.D., P.E. J D C P EJames D. Cooper, P.E.

Federal Highway Administration

Black Sea Nov. 12, 1999Aug 17 1999 Black Sea Duzce EQMw = 7.2

T = 30 sec.> 1000 Casualties(0.25g

Aug. 17, 1999Kocaeli EQ

Mw = 7.4 T = 45 sec.

17000 Casualties

Duzce

MARMARASEA

(0 8(0.41g)(0.23g)

( g)

(0.32g) (0.5g) (0.8

g)

NAF

TURKEYEpicenters and PGAsEpicenters and PGAs

Arifiye OverpassArifiye Overpass45 km east of the epicenterpConstructed in 1988AASHTO (1975) coefficient method25 ° skew25 skew4 Spans (26 m)12.5 m wide5-Simply supported precast,

pre-stressed concrete u-beamsContinuous deck cast in siteElastomeric laminated bearings

ll & l f dWall type piers & pile foundationsShear keys only at abutmentsMSE walls

RightRight--Lateral Offset = 1.5 m Lateral Offset = 1.5 m Surface Fault TraceSurface Fault Trace MSE walls

Surface Fault TraceSurface Fault Trace

Shear-key Failure

Typical UnderpassesTypical Underpasses

Typical Underpasses –yp pObserved Damage

Settlement

General View of the Viaduct #1General View of the Viaduct #1-- Total Length = 2.3 kmTotal Length = 2.3 km-- Number of Spans = 59Number of Spans = 59-- Each Span = 40 mEach Span = 40 m-- Width = 17.5 mWidth = 17.5 m

ContinuousContinuousover 10 spansover 10 spans

Width 17.5 mWidth 17.5 m-- Max. Pier Height = 49 mMax. Pier Height = 49 m-- Superstructure = 7 PS Box GirderSuperstructure = 7 PS Box Girder-- Soil Type = Type IISoil Type = Type II

A 0 4A 0 4pp

-- A = 0.4gA = 0.4g-- It was 95% completedIt was 95% completedat the time of earthquakeat the time of earthquake

-- Pile cap is 3Pile cap is 3--m thick, resting on 12 m thick, resting on 12 pp , g, gD=1.8 m CIDH piles up to 37 m in alluvD=1.8 m CIDH piles up to 37 m in alluv

Surface Fault Rupture at Viaduct #1Surface Fault Rupture at Viaduct #1

KOERIKOERI

Surface Fault Rupture at Viaduct #1Surface Fault Rupture at Viaduct #1

~~ ~~

PierPier

Pier 45 Pier 46 Pier 47

Pier Pier #45#45

40 m

~~~~

40 m 40 m40 m

* Resurveyto determine relative pier movement.Check for pile/foundation damage

40 m 40 m

Excessive Movement in Longitudinal DirectionExcessive Movement in Longitudinal Direction

EDU FailureEDU Failure

Expansion JointExpansion Joint

Lessons Learned from Turkey EQ.e EQ

Fault crossings difficult to identify If possible avoid construction near known faults Provide sufficient displacement capacity for short span bridges constructed near known faults Larger seat width -- very sound investmentProper construction and detailing of critical elements Correctly characterizing sites is very importantCorrectly characterizing sites is very importantProper selection, design, and detailing of EDUPreparedness facilitates recoveryPreparedness facilitates recovery Design & construction Q-C imperativeAwareness / information dissemination

Taiwan Chi-Chi EQ. 1999: First EQ. Report from Central Weather BureauReport from Central Weather Bureau

Chi-Chi Earthquake, Taiwan 9/21Taiwan, 9/21, 2007

LocalLocal Magnitude = 7.3

Reverse Fault

1. DIP-SLIP FAULTSa) Normal Fault normal-slip fault, tensional fault or gravity fault

b) Reverse Faultthrust fault, reverse-slip fault or compressional fault

]

Fault Motion2. STRIKE-SLIP FAULTtranscurrent fault, lateral fault, tear fault or wrench faul]

3. OBLIQUE-SLIP FAULT

Design Codes for Taiwanese Highway BridgesHighway Bridges

Prior to Varies Bridges Based on Japanese Prior to 1960

Design Spec. p

Bridge Design Codes

Standard S ifi ti f

Based on 1953 1960

Specification for Highway Bridges of Taiwan

AASHTO Standard Specification Based on 1977

1987 2nd edition Bridge Design Codes

Based on 1977 AASHTO Specification B d 1992

1995 Current Bridge Design Codes

Based on 1992 AASHTO Specifications

Neu-Tso-Pu Creek Bridge: S ttl t i T Di tiSettlement in Transverse Directions

Substructure Damage -Fault CrossingFault Crossing

Bearing Failureg

Shi-Wei Bridgeg

Constructed 1994Constructed 19943-Spans, PCI GirdersT ll dTwo spans collapsedPiers Tilted 15 degreesSkewed bridgeFault RuptureFault Rupture

Collapse of Shi wei bridge due to liquefaction Chi chi EarthquakeCollapse of Shi-wei bridge due to liquefaction, Chi-chi Earthquake, Taiwan, September 1999

I-Jiang Bridgeg g

Constructed in 1972 Simple SupportedConstructed in 1972, Simple Supported24 spans @ 11mF lt R t lift d 1 5 t 2 d thFault Rupture uplifted 1.5 to 2m under the North Abutment12 spans collapsedOverhang Superstructures???g p

I-Jiang Bridge

Bei-Fung Bridgeg g

PCI Girder Simple SupportedPCI Girder, Simple SupportedSpans CollapsedF lt R t d N b Ab t tFault Ruptured Near by an AbutmentNew Water Fall

Bei-Fung Bridge -Fault Rupture 5-6M

Mao-Luo-Shi Bridgeg

Steel SuperstructureSteel SuperstructureC-bents Type Connection (Eccentrically)H i t l C dHorizontal Curved Pier Top Concrete Spalling and Shear CracksSuperstructure Settled p

Mao-Lo-Shi Bridgeg

Mau-Lo-Shi Bridgeg

Mau-Lo-Shi Bridgeg

Vertical/Horizontal AccelerationAcceleration

Tong-Tou Bridgeg g

PCI Girder SuperstructurePCI Girder SuperstructureSpans CollapseF lt R tFault RuptureAbutments movedLiquefaction under abutment foundations and approachesppPiers Fractured

Failure of shear-critical columns in Tong-tou bridge, Chi-chi Earthquake, Taiwan, September 1999p

Shear failure in pier of Wu-shi bridge, Chi-chi Earthquake, Taiwan, September 1999

Lessons Learned Fault ruptureNear field ground motionsNear-field ground motionsGround failures precipitate structural f ilfailureAbutment back-walls and back -fills are essential for continuous bridgesShear failures must be avoided in pierspShear keys are required to prevent spans falling transverselyspans falling transversely

Issues

Shear Key DesignShear Key DesignNear Fault EffectsB i D iBearing DesignRestorationRetrofitting

How to construct (or reconstruct) a bridge across a known fault?across a known fault?

Other Infrastructure ComponentsComponents

DamDamBuildingsH bHarborLiquefactionHuge Land Slides

Shi-Gang Dam- Fault Rupture g p

Kung-Fu Elementary Schoolg y

Kung-Fu Elementary Schoolg y

Huge Landslideg

Huge Landslideg

Challengeg

H ld t t b idHow would you construct a bridge across a known fault?

Nisqually (Olympia) EarthquakeEarthquake

10:54 a m local time10:54 a.m. local timeWednesday, February 28, 2001E i t 11 il th t f Ol iEpicenter: 11 miles northeast of OlympiaHypocenter: 30 milesMagnitude: 6.8

Fourth Avenue Bridge, Olympia

Shear Cracks in Column

M li B id S ttlMagnolia Bridge, Seattle

Damaged Concrete T-Brace

Holgate Bridge - Column Failure

Fourth Avenue Ramp to I-90, Seattle

Damaged Bearing

Capitol Blvd. U-Xing - damagedend diaphragm and laterals

Alaskan Way ViaductTemporary Shoring atDamaged Knee Joint

Niigata Earthquake, Japan 20072007•Date: July 16th, 2007. Th h t d th•The hypocenter depth

is approximately 17 km. •The magnitude of this gearthquake was 6.8, •11 people were killed and 1300 peopleand 1300 people injured. •2000 houses were

l t l ll dcompletely collapsed or partially collapsed.

Pisco, Peru Earthquake , 2007, q ,

Embankment and roadway failure at Pan American Highway km 190. The picture was taken facing north. Note the Pacific Ocean in the top left of the photo. The damage was caused by liquefaction of the wet coastal silty soils that led to lateral spreading and subsequent embankment failure.embankment failure.Ground waves moving from west to east appeared to have reflected off the more rigid material on the right.

Paved shoulder on the east side of the Pan American Highway was shoved up against the ridge in the background when liquefied coastal soils sloshed laterally.

Pavement damage from liquefactionPan American Highway km 220 near San Clemente, Peru

Severe cracking of Pier 2 (from South end) necessitates extensive repair but the horizontal shear blocks managed to retrain lateral movement of the superstructure.

Multiple hazard Issue: Huachinga Bridge on Rte 110 at km 39. This steel truss bridge has suffered severe damage to the bottom chord from debris impact. There is a large granite boulder jammed between the two channels of the bottom chord that has fallen from the adjacent mountainchannels of the bottom chord that has fallen from the adjacent mountain

from this earthquake.

Multiple hazard Issue: Huachinga Bridge on Rte 110 at km 39. This steel truss bridge has suffered severe damage to the bottom chord from debris impact. There is a large granite boulder jammed between the two channels of the bottom chord that has fallen from the adjacent mountain from this earthquakeadjacent mountain from this earthquake.

SUMMARY

LESSONS LEARNED

EARTHQUAKE DISASTERS

Newer Designs Improve Performance

Retrofit Helps…but………..

U.S. Seismicity Not Well Understood