Transcript DISASTER PREPAREDNESS. Part III

DISASTER PREPAREDNESS
A KEY ELEMENT OF BECOMING
DISASTER RESILIENT
Walter Hays, Global Alliance for
Disaster Reduction, University of
North Carolina, USA
RISK ASSESSMENT
•EARTHQUAKES
•INVENTORY
•VULNERABILITY
•LOCATION
ACCEPTABLE RISK
RISK
UNACCEPTABLE RISK
GOAL: DISASTER
RESILIENCE
DATA BASES
AND INFORMATION
CITY
FOUR PILLARS OF
RESILIENCE
HAZARDS:
GROUND SHAKING
GROUND FAILURE
SURFACE FAULTING
TECTONIC DEFORMATION
TSUNAMI RUN UP
AFTERSHOCKS
•PREPAREDNESS
•PROTECTION
•EMERGENCY RESPONSE
•RECOVERY IENCE
A FOCUS ON
THE TECHNIQUE OF
DEVELOPING A DISASTER
PLANNING SCENARIO
EXAMPLES COMPLETED NEXT LECTURE
PURPOSE:
Information
from disaster
scenarios will facilitate the
adoption and implementation
of policies and plans to
enable a city to be well
prepared for future events.
DISASTERS OCCUR WHEN--A CITY’S (COMMUNITY’S)
PUBLIC POLICIES LEAVE IT …
UN—PREPARED
FOR THE INEVITABLE NATURAL HAZARDS
GLOBAL GOAL:
FROM UN—PREPARED
TO
A STATE OF
PREPAREDNESS
FOR ALL CITIES AND ALL
NATURAL HAZARDS
TECHNIQUE
SUMMARY
• A risk assessment is the
probabilistic integration of:
• The hazard (e.g., earthquakes)
and their potential disaster agents
(ground shaking, etc) and
• The exposure, location and
vulnerability of elements of the
city’s built environment).
SUMMARY: HAZARD
ENVIRONMENT
• The parameters of the hazard
environment control the primary
disaster agents of ground shaking
and ground failure and the
secondary disaster agents of
surface fault rupture, tsunami wave
run up, seiche, regional tectonic
deformation, and aftershocks.
SUMMARY: BUILT
ENVIRONMENT
• The built environment is comprised
of buildings and infrastructure (the
exposure, or the elements at risk),
each having a relative vulnerability
to a specific potential disaster
agent such as ground shaking.
HAZARD MAPS
BASED ON A
PROBABILISTIC MODEL
REQUIRED INFORMATION
•
•
•
•
Location of active faults.
Geometry of the faults.
Regional tectonic setting.
Spatial and temporal
characteristics of seismicity
REQUIRED INFORMATION
• Rate of decay of seismic energy
with distance from the point of
fault rupture.
• Magnitude, other source
parameters, and geologic
structure.
REQUIRED INFORMATION
• The physical properties of
shallow, near-surface soils.
• Construction materials of the
exposure (buildings and
infrastructure)
GROUND SHAKING
• Ground shaking is characterized by
two primary parameters: 1) the
acceleration time history, and 2) its
spectral acceleration.
• Each varies as a function of
magnitude, distance from the fault
zone, and the properties of the local
soil and rock column.
TIME HISTORY AND SPECTRA
CONSTRUCTING A PROBABILISTIC
EARTHQUAKE HAZARD MAP
SESMIC SOURCES
ATTENUATION
RECURRENCE
PROBABILITY
CONSTRUCTING A MAP
• The first step is to choose one of
the following parameters to map:
• Intensity (Typically MMI values)
• Peak ground acceleration
(Typically PGA values)
• Spectral acceleration (Typically
0.2 s period (short buildings)
and/or 1.0 s period (tall buildings)
CONSTRUCTING A MAP
• The second step is to choose an
appropriate scale for the
application and prepare a grid of
points (e.g., 0.05 degree latitude
and longitude)
CONSTRUCTING A MAP
• The final steps are to add the
layers of data, such as:
• The geographic boundaries and
cultural features of the community.
• The fault systems.
• The seismicity.
• Seismic attenuation and soil
EXAMPLE: ATTENUATION
EXAMPLE OF SOIL
AMPLIFICATION
CALCULATIONS
• Perform calculations for an
exposure time (e.g., 50 or 100
years), and exceedance probability
(e.g., 2 % or 10 %).
FROM A GROUND SHAKING
MAP TO PUBLIC POLICY
A map format facilitates
dialogue on the best ways to
form public policy for
protecting the city’s essential
facilities and critical infrastructure, another key element
of disaster resilience.
EXPECTED LOSS, VULNERABILTY, AND
GROUND SHAKING
MEAN DAMAGE RATIO,
% OF REPLACEMENT VALUE
35
30
25
20
15
10
5
0
V
VI
VII
INTENSITY
VIII
IX
POLICY CONSIDERATIONS: GROUND
SHAKING VARIES ACROSS USA
POLICY ENVIRONMENT
• A city’s leaders make the decisions on
what it will do to control and reduce its
perceived risks (e.g., by adopting and
implementing policies such as building
codes, and lifeline standards to
protect, and retrofit and rehabilitation
to sustain).
RISK MODELING
BASED ON HAZUS-MH
(OR A COMPARABLE MODEL)
RISK ASSESSMENT
• The exposure (e.g., people, and
elements of the community’s built
environment) represent the TYPE
and EXTENT of loss that is
possible.
RISK ASSESSMENT (Continued)
• The vulnerability (or fragility) of
each element comprising the
exposure affect nature and extent
of damage and potential for
collapse and loss of function.
RISK ASSESSMENT (Continued)
• The location of each element of
the exposure in relation to the
hazard (ground shaking) affects
the severity of shaking and
potential damage.
RISK ASSESSMENT (continued)
• The uncertainty in parameters that
characterize the hazard and built
environments affect decision
making.
EARTHQUAKE DISASTER
PLANNING SCENARIOS
NOTE: TECHNIQUE THIS
LECTURE; RESULTS NEXT
LECTURE)
(SAN FRANCISCO BAY AREA): EARTHQUAKE DISASTER PLANNING SCENARIO
• WHERE WILL THE
EARTHQUAKE OCCUR?
• HOW BIG? HOW CLOSE?
• HOW DEEP? WHEN?
• THE DISASTER AGENTS?
• VULNERABILITIES IN THE
BUILT ENVIRONMENT?
• EXPECTED DAMAGE?
• EXPECTED SOCIOECONOMIC IMPACTS?
(LAS ANGELES AREA): EARTHQUAKE
DISASTER PLANNING SCENARIO
• WHERE WILL THE
EARTHQUAKE OCCUR?
• HOW BIG? HOW CLOSE?
• HOW DEEP? WHEN?
• THE DISASTER AGENTS?
• VULNERABILITIES IN THE
BUILT ENVIRONMENT?
• EXPECTED DAMAGE?
• EXPECTED SOCIOECONOMIC IMPACTS?
(SEATTLE, WA AREA): EARTHQUAKE
DISASTER PLANNING SCENARIO
• WHERE WILL THE
EARTHQUAKE OCCUR?
• WHEN?
• HOW BIG? HOW CLOSE?
• THE DISASTER AGENTS?
• VULNERABILITIES IN THE
BUILT ENVIRONMENT?
• EXPECTED DAMAGE?
• EXPECTED SOCIOECONOMIC IMPACTS?
(MEMPHIS, TN AREA): EARTHQUAKE
DISASTER PLANNING SCENARIO
• WHERE WILL THE
EARTHQUAKE OCCUR?
• HOW BIG? HOW CLOSE?
• HOW DEEP? WHEN?
• THE DISASTER AGENTS?
• VULNERABILITIES IN THE
BUILT ENVIRONMENT?
• EXPECTED DAMAGE?
• EXPECTED SOCIOECONOMIC IMPACTS?
(TOKYO, JAPAN AREA): EARTHQUAKE
DISASTER PLANNING SCENARIO
• WHERE WILL THE
EARTHQUAKE OCCUR?
• HOW BIG? HOW CLOSE?
• HOW DEEP? WHEN?
• THE DISASTER AGENTS?
• VULNERABILITIES IN THE
BUILT ENVIRONMENT?
• EXPECTED DAMAGE?
• EXPECTED SOCIOECONOMIC IMPACTS?
VULNERABILITY OF ELEMENTS
• Note: Each element has a unique
vulnerability (fragility) to earthquake
ground shaking as the result of flaws
that enter during the planning, siting,
design, construction, use, and
maintenance of individual buildings
and elements of infrastructure.
VULNERABILITY
• An element’s vulnerability is
related to varying designs,
ranging from non-engineered
(e.g., a single-family dwelling) to
engineered (e.g., a high-rise
building).
VULNERABILITY
• Vulnerability is related to varying
ages of construction, which also
means varying editions of the
building code and its seismic
design provisions.
VULNERABILITY
• Vulnerability is related to varying
construction materials (e.g.,
wood, un-reinforced masonry, unreinforced concrete, reinforced
concrete, light metal, and steel).
VULNERABILITY
• Vulnerability is related to the
design for varying service lives
(e.g., 30 years for the half-life of a
class of houses; 40 years for a
class of bridges, etc.).
VULNERABILITY
• Vulnerability is related to varying
configurations (i.e., elevations
and floor plans).
• NOTE: The greater the vulnerability the higher the potential for
the building to collapse)
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
1-2
Box
None, if attention
given to foundation
and non structural
elements. Rocking
may crack foundation
and structure.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
4-6
Inverted Pyramid
Top heavy,
asymmetrical structure
may fail at foundation
due to rocking and
overturning.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
CONFIGURATION
[1 (Best) to 10 (Worst)]
2-3
Multiple Setbacks
Vertical transition in
mass, stiffness, and
damping may cause
failure at foundation
and transition points
at each floor.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
5-6
“L”- Shaped
Building
Asymmetry and
horizontal transition in
mass, stiffness and
damping may cause
failure where lower
and upper structures
join.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
3-5
Inverted “T”
Vertical transition and
asymmetry may cause
failure where lower
part is attached to
tower.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
6-7
Partial “Soft” Story
Horizontal and vertical
transitions in mass
and stiffness may
cause failure on soft
side of first floor;
rocking and
overturning.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
4-5
Overhang
Top heavy
asymmetrical structure
may fail at transition
point and foundation
due to rocking and
overturning.
ANALYSIS OF VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
8 - 10
“Soft” First Floor
Vertical transitions in
mass and stiffness
may cause failure on
transition points
between first and
second floors.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
8-9
Theaters and
Assembly Halls
Horizontal and vertical
transition in stiffness
and cause failure of
individual members.
URATION CONFIG VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 10
Combination of
“Soft” Story and
Overhang
Horizontal and vertical
transitions in mass
and stiffness may
cause failure at
transition points and
possible overturning.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 10
Sports Stadiums
Horizontal and vertical
transition in mass and
stiffness may cause
failure columns.
CONFIGURATION VULNERABILITY
BUILDING
LOCATIONS OF
ELEVATION
POTENTIAL FAILURE
RELATIVE
VULERABILITY
[1 (Best) to 10 (Worst)]
10
Building on
Sloping Ground
Horizontal transition in
stiffness of soft story
columns may cause
failure of columns at
foundation and/or
contact points with
structure.
THE GOAL OF EVERY CITY
• WELL PREPARED
FOR ALL
NATURAL
HAZARDS (E.G.,
FLOODS,
SEVERE
WINDSTORMS,
EARTHQUAKES,
ETC.)
DISASTER PREPAREDNESS
IS A “24/7” EFFORT
• KNOW YOUR
HAZARDS
• KNOW YOUR CITY
• KNOW WHAT TO
DO WHEN…
• KNOW HOW TO DO
IT WHEM…