Seismic Lessons Learned W. Phillip Yen, Ph.D., P.E.SSeismic Research Program ManagerOffice of Infrastructure R&D, FHWA [email protected]
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