LESSONS FROM PAST NOTABLE EARTHQUAKES. Part III

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LESSONS FROM PAST NOTABLE EARTHQUAKES. Part III
Walter Hays, Global Alliance for Disaster
Reduction, Vienna, Virginia, USA 
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PAST NOTABLE EARTHQUAKES

• LOMA PRIETA, CALIFORNIA
• OCTOBER 17, 1989

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EARTHQAKES ARE DYNAMIC LABORATORIES FOR LEARNING
AND CATALYSTS FOR BUILDING CAPACITY FOR
DISASTER-INTELLIGENT DISASTER-RESILIENT
COMMUNITES

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LOCATION

• The epicenter was located near Loma Prieta peak
  in the Santa Cruz Mountains, approximately 14 km
  (9 mi) northeast of Santa Cruz and 96 km (60 mi)
  south-southeast of San Francisco

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OCCURRENCE
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CALIFORNIAS FAULTS (SOURCE CA. GEOL. SURVEY)
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The Loma Prieta Earthquake was Forecast (USGS,
1988)
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Schematic Diagram of the Loma Prieta Earthquake
Mechanism
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Schematic Diagram of the Earthquake Rupture
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THE LOMA PRIETA EARTHQUAKE

• Mw 6.9 Ms 7.1
• Depth 18 km (11 miles)
• 504 pm local time
• Soil amplification effects in San Francisco Bay
  region

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SAN FRANCISCO BAY REGION (EPICENTER TOP LEFT)
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SOIL AMPLIFICATION MAP SAN FRANCISCO BAY REGION
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CAUSES OF DAMAGE
INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT (SURFACE FAULTING GROUND
FAILURE)
IRREGULARITIES IN ELEVATION AND PLAN
EARTHQUAKES
FIRE FOLLOWING RUPTURE OF UTILITIES
DISASTER LABORATORIES
LACK OF DETAILING AND CONSTRUCTION MATERIALS
INATTENTION TO NON-STRUCTURAL
ELEMENTS
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IMPACTS BUILDINGS
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SAN FRANCISCO BAY REGION

• Buildings and infrastructure of all types and
  ages, constructed in accordance with various
  codes/standards, FAILED in the San Francisco Bay
  Region.

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LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES
• PREPAREDNESS PLANNING FOR THE INEVITABLE STRONG
  GROUND MOTION IS ESSENTIAL FOR COMMUNITY
  RESILIENCE.

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LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES
• PROTECTION OF BUILDINGS AND INFRASTRUCTURE IS
  ESSENTIAL FOR COMMUNITY RESILIENCE.

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PROBABILISTIC MAPS OF PEAK GROUND ACCELERATION
(PGA) AND SPECTRAL ACCELERATION (SA) ARE BASIC
TOOLS USED IN BUILDING CODES AND INFRASTRUCTURE
STANDARDS
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GROUND SHAKING (Peak ground acceleration)
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GROUND SHAKING WESTERN USA
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PGA SAN FRANCISCO BAY REGION
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Sa 0.3 S SAN FRANCISCO BAY REGION (Short bldgs.)
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Sa 1.0 S SAN FRANCISCO BAY REGION (tall bldgs,)
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LOMA PRIETA EARTHQUAKE

• 1,300 BUILDINGS DESTROYED
• 20,000 BUILDINGS DAMAGED
• 3,500 BUSINESSES DAMAGED
• TRANSPORTATION LOSSES ALONE 1.8 BILLION

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VULNERABLE UNREINFORCED MASONRY BUILDINGS
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VULNERABLE UNREINFORCED MASONRY BUILDINGS
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VULNERABLE SOFT-STORY BUILDINGS MARINA DISTRICT
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LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES
• PREPAREDNESS PLANNING FOR THE INEVITABLE GROUND
  FAILURE IS ESSENTIAL FOR COMMUNITY RESILIENCE.

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GROUND FAILURE, NOT SURFACE FAULT RUPTURE
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LATERAL SPREADING SAN FRANCISCO WHARF AREA
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LIQUEFACTION MARINA DISTRICT
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AS IN 1906, FIRE BEGAN IN THE MARINA DISTRICT
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CYPRESS FREEWAY A PROTECTION NIGHTMARE
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FAILURE OF A SPAN ON THE OAKLAND BAY BRIDGE A
COMMUTERS NIGHTMARE
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LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES
• CAPACITY FOR EMERGENCY RESPONSE IS ESSENTIAL FOR
  COMMUNITY RESILIENCE.

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POWER OUTAGES BEGAN AT 504 PM IN THE REGION
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CYPRESS FREEWAY COLLAPSE AN EMERGENCY RESPONSE
NIGHTMARE
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FORTY-ONE VICTIMS AT THE CYPRESS FREEWAY
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FIRE IN MARINA DISTRICT 100 KM FROM EPICENTER
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LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES
• CAPACITY FOR RECOVERY AND RECONSTRUCTION IS
  ESSENTIAL FOR COMMUNITY RESILIENCE.

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RESTORATION OF WIDESPREAD POWER OUTAGES TOOK TIME
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RESTORATION OF TRANSPORTATION ON CYPRESS FREEWAY
TOOK TIME
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RESTORATION OF TRANSPORTATION ON OAKLAND BAY
BRIDGE TOOK TIME
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EARTHQUAKE INSURANCE WAS A TOOL FOR RECOVERY

• EARTHQUAKE INSURANCE SPREADS THE RISK AND
  SPEEDS RECOVERY BY FACILITATING THE RESTORATION
  TO NORMAL

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PLANNING FOR THE FUTURE

• A NEW GENERATION OF POLICIES AND PROFESSIONAL
  PRACTICES FOR SITING, DESIGN, AND CONSTRUCTION IN
  CALIFORNIA AND OTHER EARTHQUAKE PRONE REGIONS OF
  THE USA.

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SAN FRANCISCO AIRPORT BASE ISOLATION
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SAN FRANCISCO CITY HALL BASE ISOLATION
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SUMMARY OF IMPACTS

• 62 DEATHS (Mostly at Cypress Freeway)
• 3,757 INJURIES
• 8,000 HOMELESS
• 5.6 BILLION PROPERTY DAMAGE WITH THE FIRST 1.8
  BILLION EARTHQUAKE INSURANCE INDEMNIFICATION
• MAJOR FLAWS IN PROTECTION OF TRANSPORTATION
  INFRASTRUCTURE

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PRIMARY SOURCES OF INFORMATION ON THE LOMA PRIETA
EARTHQUAKE ARE 1) The US Geological Survey,
2) The California Geological Survey, and
3) the Earthquake Engineering Research
Institute