Earthquake Impacts -Earthquake Impacts -THE Midwest ThreatTHE Midwest Threat

Gregory L. Hempen, PhD, PE, RGGregory L. Hempen, PhD, PE, RG

Geophysicist (retired, St. Louis District)Geophysicist (retired, St. Louis District)

URS Corporation, St. Louis Office URS Corporation, St. Louis Office

SAME Regional Conference, 5 OCT 06SAME Regional Conference, 5 OCT 06

Natural Hazard IssuesNatural Hazard Issues natural hazards: eqks, ... natural hazards: eqks, ...

our special Midwest problems our special Midwest problems sustained-design environment sustained-design environment risk acceptancerisk acceptance probabilities of extremesprobabilities of extremes

Earthquakes - Where? When? Earthquakes - Where? When? No Advance Warning! No Advance Warning!

Tornadoes are more common in the Tornadoes are more common in the Midwest, but impact far less area. Midwest, but impact far less area.

Some equivalence with other rapidly Some equivalence with other rapidly developing hazards: high wind developing hazards: high wind threats, seismic related hazards threats, seismic related hazards (liquefaction, lateral spreading, (liquefaction, lateral spreading, slope instability), terrorism, … slope instability), terrorism, …

An all-hazards approach is best. An all-hazards approach is best.

Where? Epicenters & Where? Epicenters & SourcesSources

Clarendon-Lindon Seismic Zone

EasternTennesse

Seismic Zone

New Madrid Seismic Zone

Anna, Ohio Seismic Zone

Wabash Valley Seismic Zone

St. Lawrence Seismic Zone

Giles County Seismic Zone

Charleston Seismic Zone

Ottawa Seismic Zone

Charlevoix Seismic Zone

Central Virginia Seismic Zone

NY-NJ-PA Seismic Zone

New England Seismic Zone

EARTHQUAKES OF THE CENTRAL AND EASTERN UNITED STATES1627 - 1991

Catalog of the National Center for Earthquake Engineering Research

EQE International

EQE International Inc.

20 APR 02, M20 APR 02, MLL 5.1, 5.1, Plattsburgh NY EarthquakePlattsburgh NY Earthquake

10 SEP 06, M 5.8, 10 SEP 06, M 5.8, Gulf of Mexico EarthquakeGulf of Mexico Earthquake

USGS

CENTRAL US SOURCE CENTRAL US SOURCE ZONESZONESSeismic Source ZonesSeismic Source Zones

8.6

7.5

6.5

6.5

6.5

6.5

7.5

PaducahGravity Low

New MadridSeismic Zone

Southern IllinoisSeismic ZoneWaterloo-Dupo

Seismic Zone

Ozark MountainsSeismic Zone

CommerceFault Zone

5.5

5.5

5.5

Wabash ValleySeismic Zone

Eastern TennesseeSeismic Zone

7.5

Appalachian ForelandSeismic Zone

5.5

5.5

When?When?

Multiple timeframes & reference sets.Multiple timeframes & reference sets. For a future earthquake:For a future earthquake:

When will the earthquake occur? What year? When will the earthquake occur? What year? How long will the earthquake last? How long will the earthquake last? One big earthquake, right? One big earthquake, right?

Emergency response, response, recovery: Emergency response, response, recovery: When will emergency help arrive? When will emergency help arrive? How long will response take? How long will response take? How long will recovery take? To get back to How long will recovery take? To get back to

“normal?” “normal?”

New Madrid Seismic ZoneNew Madrid Seismic Zone Commerce-Benton HillsCommerce-Benton Hills

East Prairie Limb, NMSZ East Prairie Limb, NMSZ M: M: a a 8.1, 8.1, bb 8.1 8.1, , cc 7.2 7.2

Reel-foot Thrust Limb, Reel-foot Thrust Limb, NMSZ NMSZ M: M: a a 8.0, 8.0, bb 8.0 8.0, , cc 8.0 8.0

Blytheville Arch Limb, Blytheville Arch Limb, NMSZ NMSZ M: M: a a 7.8, 7.8, bb 7.0 7.0, , cc 7.8 7.8

Tuttle, et al, 2002Tuttle, et al, 2002 aa 1811 – 1812 AD 1811 – 1812 AD bb 1450 AD 1450 AD cc 900 AD 900 AD

When relative to the hazard?When relative to the hazard?

When will the earthquake occur? When will the earthquake occur? Large events recur about every 550 years (Cramer, Large events recur about every 550 years (Cramer,

2006). 2006). Intraplate strains and energy release by the Intraplate strains and energy release by the

magnitude scale suggests a M6 event perhaps magnitude scale suggests a M6 event perhaps every 50 years. every 50 years.

M6, 70 - 90 yr; M7, 250 - 500 yr; M8, 550 – 1,200 M6, 70 - 90 yr; M7, 250 - 500 yr; M8, 550 – 1,200 yr (Rogers, 2005). Overdue for M6; M7 possible. yr (Rogers, 2005). Overdue for M6; M7 possible.

How long will the earthquake shaking last? How long will the earthquake shaking last? 60 sec, M8; 30 sec, M7; 18 sec, M6 (Krinitzsky & 60 sec, M8; 30 sec, M7; 18 sec, M6 (Krinitzsky &

Chang, 1977).Chang, 1977). One big earthquake, right? One big earthquake, right?

No, likely a foreshock with one or more main No, likely a foreshock with one or more main events within days to months (several references).events within days to months (several references).

When for response issues?When for response issues?

When will emergency help arrive for the public? When will emergency help arrive for the public? Hours to days later, depending upon event size, Hours to days later, depending upon event size,

location within the damaged area, and location within the damaged area, and government preparation. [Supplies for 7 days.]government preparation. [Supplies for 7 days.]

How long will response take? How long will response take? Weeks to months, depending upon extent of the Weeks to months, depending upon extent of the

event’s damage and government preparation. event’s damage and government preparation. How long will recovery take to get back to How long will recovery take to get back to

“normal?” “normal?” M6 recovery will take months to get back to M6 recovery will take months to get back to

some normalcy. M7 and larger will have long-some normalcy. M7 and larger will have long-term effects and may never return to present term effects and may never return to present economic conditions. economic conditions.

No Advance Warning!No Advance Warning! Even a M6.5 to 7.0 in the Midwest will be a Even a M6.5 to 7.0 in the Midwest will be a

devastating and society-changing event. devastating and society-changing event. There may be no warning at all. There may be no warning at all.

Even the 1993 Mississippi flooding is a poor Even the 1993 Mississippi flooding is a poor model for earthquake damage. model for earthquake damage.

Hurricane Katrina is a more similar analogy Hurricane Katrina is a more similar analogy in the wide spread damage to structures in the wide spread damage to structures and lifelines (dominantly levee, electrical and lifelines (dominantly levee, electrical transmission, and telephone systems). transmission, and telephone systems).

1900 Galveston Hurricane, 1954 Hurricane 1900 Galveston Hurricane, 1954 Hurricane Hazel & 1966 Hurricane Inez, having Hazel & 1966 Hurricane Inez, having practically no warning but wide spread practically no warning but wide spread devastation, compare better to a large devastation, compare better to a large earthquake in the Eastern US.earthquake in the Eastern US.

Special Central US Special Central US ConcernsConcerns

Complacency Complacency PreparednessPreparedness Similarities to Katrina Disaster Similarities to Katrina Disaster Use of Eqk Codes Use of Eqk Codes

Low attenuation Low attenuation Great area of significant ground Great area of significant ground

shakingshaking Dispersion – long/tall structure impacts Dispersion – long/tall structure impacts

Liquefaction / Lateral Spreading Liquefaction / Lateral Spreading and Foundation impactsand Foundation impacts

CA & CENTRAL US MMICA & CENTRAL US MMI

Structures & RisksStructures & Risks Significant ground motion at greater Significant ground motion at greater

distance. distance. Due to dispersion of the waves, distant Due to dispersion of the waves, distant

structures may be placed into structures may be placed into resonance.resonance. Long or tall structures are particularly Long or tall structures are particularly

susceptible to resonance effects. susceptible to resonance effects. More distant towns: tall buildings in More distant towns: tall buildings in

Chicago; bridges across major rivers; dams; Chicago; bridges across major rivers; dams; pipelines.pipelines.

Evaluation of geotechnical issues: Evaluation of geotechnical issues: activation of slides, liquefaction/lateral activation of slides, liquefaction/lateral spreading, bearing capacity, differential spreading, bearing capacity, differential settlement.settlement.

New Madrid Seismic ZoneNew Madrid Seismic Zone Commerce-Benton HillsCommerce-Benton Hills

East Prairie Limb, NMSZ East Prairie Limb, NMSZ M: M: a a 8.1, 8.1, bb 8.1 8.1, , cc 7.2 7.2

Reel-foot Thrust Limb, Reel-foot Thrust Limb, NMSZ NMSZ M: M: a a 8.0, 8.0, bb 8.0 8.0, , cc 8.0 8.0

Blytheville Arch Limb, Blytheville Arch Limb, NMSZ NMSZ M: M: a a 7.8, 7.8, bb 7.0 7.0, , cc 7.8 7.8

Tuttle, et al, 2002Tuttle, et al, 2002 aa 1811 – 1812 AD 1811 – 1812 AD bb 1450 AD 1450 AD cc 900 AD 900 AD

Infrastructure - Dams & Infrastructure - Dams & LeveesLevees

Wappapello’s 2002 High-Water Wappapello’s 2002 High-Water EventEvent

Emergency Overflow Spillway

Outlet Works & Tunnel

Embankment Dam with flat slopes & crest road

Designed in the 1930’s & completed in 1941, its defensive measures are the dam’s stiff, gravelly clay, wide embankment base, & high freeboard.

SUSTAINED DESIGN – SUSTAINED DESIGN – Integration of the HazardIntegration of the Hazard

Hazard assessmentHazard assessment Acceptance of risk OR Acceptance of risk OR

mitigation of risk OR lessening mitigation of risk OR lessening of project requirements of project requirements

Risk to be mitigated Risk to be mitigated Design to be resolvedDesign to be resolved

HAZARD versus RISKHAZARD versus RISK

HazardHazard - an occurrence that imperils - an occurrence that imperils life or property [assessed by science].life or property [assessed by science].

RiskRisk - quantification of a known - quantification of a known hazard to an inventory (of life or hazard to an inventory (of life or property) that is vulnerable [mitigated property) that is vulnerable [mitigated by engineering]; the risk may be by engineering]; the risk may be apportioned between apportioned between acceptanceacceptance of or of or mitigationmitigation of the hazard [distributed of the hazard [distributed by the owner’s policy]. by the owner’s policy].

SITE & HAZARD SITE & HAZARD ASSESSMENTASSESSMENT

Earthquake sources and seismicity Earthquake sources and seismicity Travel path parameters Travel path parameters Static & dynamic parameters of earth Static & dynamic parameters of earth

systems (naturally placed, not designed) systems (naturally placed, not designed) Site response analysis Site response analysis Other hazard impacts Other hazard impacts Engineering designs to abate the Engineering designs to abate the

hazards’ risk and meet the projects’ hazards’ risk and meet the projects’ requirementsrequirements

SEISMIC DAMAGE TYPESSEISMIC DAMAGE TYPES

Fault displacement (rupture)Fault displacement (rupture) Ground motion (induced inertia)Ground motion (induced inertia) Indirect Physical Impacts Indirect Physical Impacts

Tectonic Changes (seiches / tsunamis) Tectonic Changes (seiches / tsunamis) Liquefaction Liquefaction Triggering Landslides Triggering Landslides Foundation Failures (Diffrt’l Foundation Failures (Diffrt’l

Settlement) Settlement) Tertiary Lifeline ImpactsTertiary Lifeline Impacts

IMPACTED EPICENTRAL IMPACTED EPICENTRAL DISTANCES (km)DISTANCES (km)

MMWW

Failure TypesFailure Types

5.85.8 6.36.3 7.67.6 8.38.3

FoundationFoundation 4040 7070 170170 270270

LiquefactionLiquefaction 1515 4040 230230 400400

SlopeSlope 6060 110110 280280 450450

CODES - Seismic Provisions CODES - Seismic Provisions of the 2003 IBCof the 2003 IBC

Sections 1613 through 1616 of the 2003Sections 1613 through 1616 of the 2003 IBC pertain to Earthquake Loads on structures IBC pertain to Earthquake Loads on structures

with rules for exceptions, existing structure with rules for exceptions, existing structure additions, occupancy, alterations, QA, & wind.additions, occupancy, alterations, QA, & wind.

Design spectral response acceleration, SA, is Design spectral response acceleration, SA, is specified fromspecified from Mapped bedrock acc [Mapped bedrock acc [Eqk Source RegionEqk Source Region]: SS & S1, ]: SS & S1, Site Class Determination [Site Class Determination [Site AssessmentSite Assessment] – ] –

T 1615.1.1, T 1615.1.1, Site Class Coefficients - T 1615.1.2(1&2), & Site Class Coefficients - T 1615.1.2(1&2), & The The structurestructure’s fundamental period, T, in s. ’s fundamental period, T, in s.

OTHER SEISMIC OTHER SEISMIC HAZARDSHAZARDS

(not only the ground motion (not only the ground motion value)value)

Fault displacement Fault displacement Tectonic Changes [Tectonic Changes [seichesseiches (waves) / (waves) /

tsunamis] tsunamis] Foundation ImpactsFoundation Impacts

Dynamic Bearing CapacityDynamic Bearing Capacity Differential Settlement Differential Settlement Liquefaction (Flow Liq, Cyc Mobility, Cyc Liq)Liquefaction (Flow Liq, Cyc Mobility, Cyc Liq)

Triggering LandslidesTriggering Landslides Tertiary Lifeline or Project Subsystem Tertiary Lifeline or Project Subsystem

Impacts Impacts

Probabilities of ExtremesProbabilities of Extremes

Standard statistical assessments have Standard statistical assessments have been used. Earthquakes are not been used. Earthquakes are not independent events. independent events.

Stresses within the plate increase in Stresses within the plate increase in time so the risk increases with time. time so the risk increases with time.

Statistics of once or more Statistics of once or more occurrences. occurrences.

2% exceedance in 50 years 2% exceedance in 50 years (x(x>>1 in 2,450-year period). 1 in 2,450-year period).

Statistics for the Statistics for the UncommonUncommon

Earthquake swarms: several events in Earthquake swarms: several events in one areaone area

Foreshocks & Aftershocks use little of Foreshocks & Aftershocks use little of the main event’s energythe main event’s energy

New Madrid Series, 1811-12, within 8 New Madrid Series, 1811-12, within 8 months:months: 3 or 4 Great (?) Earthquakes 3 or 4 Great (?) Earthquakes 10 – 15 Large Earthquakes 10 – 15 Large Earthquakes Scores of Major EarthquakesScores of Major Earthquakes

Actions for EarthquakesActions for Earthquakes For your awareness, you can For your awareness, you can

improve your survivability improve your survivability and your resources’ and your resources’ sustainability.sustainability. Earthquake Preparation Earthquake Preparation During an Earthquake During an Earthquake Earthquake RecoveryEarthquake Recovery

Earthquake Preparation Earthquake Preparation

Learn first aid, Learn first aid, have water, food and supplies for three have water, food and supplies for three

days, days, prepare the structure/community for eqk,prepare the structure/community for eqk, know what to do when we feel an eqk,know what to do when we feel an eqk, have a plan to meet at a specific place have a plan to meet at a specific place

after an earthquake occurs, and after an earthquake occurs, and have an earthquake drill.have an earthquake drill.

During an EarthquakeDuring an Earthquake

When inside, stay inside at a protective When inside, stay inside at a protective location: door way, corner or beneath a location: door way, corner or beneath a sturdy table. sturdy table. Drop, coverDrop, cover, and , and holdhold.. Try to be away from windows. Try to be away from windows.

When outside, stay outside. Try to get When outside, stay outside. Try to get away from tall buildings and overhead away from tall buildings and overhead utilities. utilities.

In a car when an eqk is recognized, slow In a car when an eqk is recognized, slow and pull off at a safe location.and pull off at a safe location.

Earthquake RecoveryEarthquake Recovery

Aid those nearby, Aid those nearby, stay at a secure place until it is stay at a secure place until it is

okay to go home, okay to go home, go to your meeting place, go to your meeting place, do not go sight-seeing, and do not go sight-seeing, and expect other earthquakes, called expect other earthquakes, called

aftershocks.aftershocks.

SUMMARYSUMMARY Earthquakes should be regarded as a significant Earthquakes should be regarded as a significant

and special hazards, particularly near the and special hazards, particularly near the New Madrid Seismic Zone. New Madrid Seismic Zone.

Designs for many structures need to consider Designs for many structures need to consider the the acceptable earthquake risk. acceptable earthquake risk.

Seismic Ground Motion appraisal may be Seismic Ground Motion appraisal may be developed from accepted code developed from accepted code

procedures. procedures. Other seismic foundation impacts for the site Other seismic foundation impacts for the site

should be considered. should be considered. Be aware of individual actions before, during Be aware of individual actions before, during

and after earthquakes. and after earthquakes.