Disaster Mitigation

1
Disaster Mitigation in Health Facilities Wind
Effects Structural Issues
2
Hurricane paths in the Caribbean Region during
1998
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Hurricane Georges path - 1998
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Hurricane Mitchs path - 1998
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Floods are a very important consequence of
hurricanes
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Natural hazards impact in health facilities (1981
- 2001)
According to the Pan American Health
Organization, between 1981 and 2001 more than 100
hospitals and 650 health centers suffered serious
damages as a result of natural disasters. The
Economic Commission for Latin America and the
Caribbean (ECLAC) reported direct economic losses
of US 3,120 million. This could be compared to
an extreme situation in which 20 countries in the
region had each suffered the loss of 6 major
hospitals and 25 health centers.
7
Hospitals are specially vulnerable to natural
hazards

• The occupancy rate is constant, 24 hours a day,
  year-round.It is almost impossible to evacuate a
  hospital in the event of an emergency.
• The survival of some patients depends on the
  proper operation of the equipment and the
  continuity of basic services.
• Hospitals are highly dependent on public
  utilities (water, electricity, communications,
  etc.) which are often interrupted by the effects
  of a disaster.
• In emergencies and disasters, health facilities
  are essential and must continue to function after
  the event has taken place.

8
The ingredients a hurricane needs

• Warm water above 80ºF
• Converging winds
• Unstable air
• Humid air being pulled into the storm(up to about
  18,000 ft)
• Pre-existing winds coming from nearly the same
  direction
• An upper atmosphere high-pressure area helps pump
  away air rising in the storm

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Hurricane stages during its path towards the
Caribbean Region
Hurricane
Tropical Storm
Tropical Depression
Tropical Disturbance
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Anemogram of Hurricane Georges - 1998
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Saffir-Simpson scale for hurricane categories
Category Velocity 1 minute (km/hr) Pressure (mb) Damages
1 120 - 150 gt 980 Minimum
2 150 175 965 980 Moderate
3 175 210 945 - 965 Extensive
4 210 250 920 - 945 Extreme
5 gt 250 lt 920 Catastrophic
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Hurricanes categories in the North Atlantic and
the Caribbean Region 1944-2001
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Turbulent flow of wind on longitudinal and
transverse sides of high-rise buildings
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Turbulent flow on high-rise buildings due to
upwind obstructions
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Wind velocity increase due to large openings at
lower floors
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Wind flow on gabled roof buildings showing
turbulence on leeward roof and walls
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Winds basic pressure
Dynamic part of Bernoullis basic equation
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Different international design standards
Standard Identification
ISO International Standard Organization
CUBiC Caribbean Uniform Building Code
ENV Eurocode
DRBC Dominican Republic Building Code
AIJ Japan Standard
AS Australian Standard
BNSCP Barbados Standard
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Different calculations for design wind speeds and
dynamic pressures
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Building types in seven international wind
standards
Building Shape/Type ISO 4354 CUBiC ENV 1991 DRBC 2003 AIJ AS1170.2 BNS CP28
Stepped Roofs no no no yes no no yes
Free-standing walls yes yes yes yes no yes no
Multispan canopies no no yes yes no no no
Arched roofs yes yes yes yes yes yes yes
Domes no no yes no yes no no
Silos and tanks yes yes yes yes no yes no
Circular sections yes yes yes yes yes yes yes
Polygonal sections no no yes no no yes yes
Lattice towers yes yes yes yes no yes yes
Spheres no yes yes no no no yes
Signs yes yes yes yes yes yes yes