OMSI Science Pub - Chile Earthquake

27 February 2010 South Central Chile Earthquake Professor Scott Ashford Oregon State University Professor Jack Moehle University of California at Berkeley Professor Pedro Arduino University of Washington

Acknowledgments for this broad collaborative effort funded primarily by the National Science Foundation
Earthquake Engineering Research Institute (EERI)
Jack Moehle, Team Leader
Geo-Engineering Extreme Events Reconnaissance (GEER)
Jon Bray, Team Leader
Broad participation from Chilean Faculty and Students
Pontifica Universidad Catolica de Chile
University de Chile
Over 100 other volunteers from around the world

2010 Chile earthquake 3:34 am local time 27 February 2010 M w 8.8 Fault rupture 100km x 500 km Population affected > 8M * 521 confirmed deaths ** 190000 homes severely damaged or destroyed ~800,000 homeless ~$30B damages * ACHISINA ** USAID, 3/25/10

Pacific Northwest

Concepcion

Talca (AP Photo)

Santiago (AP PHOTO/Carlos Espinoza)

Pelluhue ( AP Photo)

Learning from Chile Geological and Geotechnical Aspects 27 February 2010 South Central Chile Earthquake June 28, 2010

Typical Subduction Zone

Recent Seismic Events Previous Events - Seismic Gap 1960-M9.5 1985-M8.0

Measured (GPS) Coseismic Horizontal Displacements Concepcion moved ~3m towards west

Coseismic Vertical Displacements Uplift up to ~2m was recorded in Lebu

Uplift Evidence

Tsunami

Ground Failure Overview
Ground Failure
Site effects & strong shaking
Liquefaction
Lateral spreading
Landslides
Infrastructure impact:
Dams, tailings dams.
Ports & harbors
Buildings
Transportation (roads & bridges)

SITE EFFECTS
Ground Failure

Site Effects: Vespucio Norte & Ciudad Empresiarial H/V peaks: 0.5-2sec (Bonnefoy et al, 2008) Damage to 5 to 20-story buildings Q fno : Silt & Clay Layers Localized Damage – Site Effects? A B A B Gravel, Sandy gravel Silty Clay, Silty Sand Collapse No collapse

LIQUEFACTION & LATERAL SPREADING
Ground Failure

Lateral Spreading Lateral spreading near river banks due to liquefaction

Gas Station - Concepción

LANDSLIDES & DAMS/TAILING DAMS
Ground Failure

Landslides Few deep seated slides were observed

Dams Most dams performed well

Dams & Levees Coihueco Zoned Earth Dam Upstream Slope Failure Levee Breach

Tailing Dams Las Palmas tailings dam failure Approximate area of failure and flow direction

Las Palmas Tailing Dam failure (cont) Besides this case, most tailings dams performed well

PORTS & HARBORS CASE STUDIES
Impacts of Ground Failure

Ports & Harbors
Provide important means for importing & exporting goods in Chile
95% of exports & 90% of imports are conducted through ports
Country has 35 operational ports (10 state owned, 25 privately owned). 2 are military ports
4 ports were inspected in the period 3/13 to 3/18 by GEER team: Valparaiso, San Antonio, Talcahuano & Coronel
Information & Assistance was provided by EERI team and local engineers.

Valparaiso: Outward quay wall movement and pavement cracks

San Antonio: Damaged dock

Talcahuano Port Area St Vincente Port Fishing Wharf Fish Packaging Facility Petroleum Facilities N

Fishing Pier 178m 24m 42m N Documented extent of lateral spread

N Approx extent of lateral spread

Lateral Spreading Effects on Industrial Facilities Fish Packing Facility, San Vicente

Petrobas Gas Facility N Fish Packaging Facility Petrobas Gas Facility Water rise Approx extent of lateral spread

Coronel: Lateral spread displacements

Coronel: Sinkholes (2.2m deep, 3.5m in diameter)

Coronel: Rotation of pile due to lateral spreading (not a raked pile!)

EMBANKMENT FAILURES
Impacts of Ground Failure

Embankment Failures along Highway 5 Possible liquefaction of thin seams in foundation soils led to translational failures of highway embankments

Valparaiso, UNESCO Heritage City

Festival Viña del Mar, 14 Stories

MASS EQ

Santiago

MASS EQ

Concepcion (AP Photo)

Collapsed building in Concepcion openings solid typical unit Plan Tower under construction parking A B Section A Section B

Santiago

Airports

Hospitals and health care

US$2 billion annual sales
Approx. 1 billion liters
70% exported
80,000 full-time workers
Chilean Wine Industry

Stainless steel tanks

Thank You

Santiago (AP PHOTO/Carlos Espinoza)

Bridge Team Members
Mark Yashinsky, Team Leader
Caltrans
Rodrigo Oviedo
Universidad Catolica de Chile
Scott Ashford
Oregon State University
Luis Fargier-Gabaldon
Universidad de los Andes, Merida .
Matias Hube
Universidad Catolica de Chile
Traveled over 2000 km from Santiago
to Temuco and back over 5 days
Nazca Plate 200 mi Valparaíso South America Plate Temuco Talca Ruta 5 Ruta 5 Santiago

shear key Temporary shoring of the beam

Vertical axis Rotation or twisting of the deck Abutment Deck Lateral displacement

Failed shear key Seismic bars Undamaged shear key

Tubul Bridge Eight span simply supported steel girders on pier walls. Collapsed attributed to unseating of beams

Summary of Observations on Bridges
Structures with less continuity generally suffered more damage
Localized damage suggests the importance of local site effects
Significant liquefaction and lateral spreading along coast greatly impacted mobility
Widespread fill settlement was easily repaired, but adversely affected traffic.

Summary of other Lifeline Performance
Electric Power
Immediate blackout to 90% of Chile’s population
Transmission capability to provide power within 24 hours
Distribution system service restored with two weeks
Telecommunication
Both landlines and wireless service serverly affected
Most cell sites ran out of battery power within 3 hours of quakes, eliminating communications with repair crews and hospitals
Most services restored within seven days
Water and Wastewater severely impacted along coast

Pelluhue ( AP Photo)

Maximum inundation 10m
Maximum run-up 30m
Loss of life limited thanks to local awareness and good signing
Most tsunami-related deaths from tourists
Tsunami

NOAA Tsunami wave heights for Feb. 27, 2010, 8.8 EQ

NOAA Tsunami wave heights, May 22 1960, 9.5 EQ

1500 homes destroyed in Dichato from tsunami; only 17 residents killed

Where do we fit in? The Pacific “Ring of Fire”

200 mi Juan de Fuca Plate Cascadia Subduction Zone Oregon Washington California Gorda Plate Pacific Plate North America Plate Seattle Portland Corvallis Salem Redding Medford Vancouver I-5 I-5 Nazca Plate 200 mi Valparaíso South America Plate Temuco Talca Ruta 5 Ruta 5 Santiago

Comparison of Haiti and Chile earthquakes
Haiti was:
Magnitude 7.0
Shallow Strike-Slip under urban area
Vulnerable infrastructure
Chile was:
Magnitude 8.8
Subduction Zone EQ covering huge area
Over 500 more powerful
Last 6 times as long
Less vulnerable infrastructure
Chile Haiti Finite fault models by Gavin Hayes, USGS National Earthquake Information Center

What are the implications for Oregon?
2010 Chile Earthquake
Peru-Chile Subduction Zone
Magnitude 8.8
Shaking and Tsunami
Modern Building Codes
$30B damages
About 500 dead
7 EQ M=8.0+ in past 100 yrs
Last M=8.0 in 1995
Occur about every 15 yrs
Future CSZ Earthquake
Cascadia Subduction Zone
Magnitude 9.0
Shaking and Tsunami
Modern Building Codes
Damages estimated at $30B*
Estimated up to 5000 dead*
No M=7.0 is past 100 years
Last M=9.0 in 1700
Occur about every 300 yrs
*Source: DOGAMI 2010

What can you do?
Take personal responsibility
Have several days of emergency supplies
Earthquake proof your home
Have a plan
Support earthquake preparedness efforts
Participate in earthquake education
Continue to support State efforts
DOGAMI tsunami hazard mapping to be completed by 2013
Seismic mitigation of public schools not complete until 2032
ODOT Phase I and II seismic retrofits
Support higher education
Innovative solutions through research and next-generation engineers

THANK YOU!
For more information:
Earthquake Engineering Research Institute
www.eeri.org
Geo-Engineering Extreme Events Reconnaissance
www.geerassociation.org
Oregon Department of Geology and Mineral Industries
www.OregonGeology.org

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