1. Resilience Against Earthquakes
Some Practical Suggestions
for Planners and Managers
David Alexander
Global Risk Forum - Davos (CH)

2. What is resilience [resiliency]?
• a combination of resistance and
adaptation (coping, capacity, capability)
• ability to maintain livelihoods and tenor
of life in the face of disaster shocks
• local autonomy and self-sufficiency.
self-sufficiency.

3. Redundancy
Redundancy
Redundancy
Redundancy
The ingredients
of resilience
Adaptability Attitude
Participation
...and
communication

4. Source: World Disasters Report 2005
Wisdom: ability to take decisions
on the basis of principles,
principles,
experience and knowledge
Knowledge: understanding of how
things function (or should function)
Information: description of
physical and social situations
Data: basic facts and statistics
COMMUNICATION

5. Knowledge
Knowledge of
of hazards
community
and their
vulerability
impacts
DRR
Knowledge
of coping
Disaster capacity and
Risk resilience
Reduction

6. Community disaster planning
Volunteerism Donations
Self-
Self-organisation Community
resources
Organisation Resources
Imposed Governmental
organisation resources
Laws, protocols, directives
Standards, norms, guidelines International resources

7. Organisation
need not be
expensive and
the cost of
communication
is continually
falling...

8. Vehicles are an important source of
people's vulnerability to earthquakes, but...

9. Vernacular
housing:
the main
source
of risk
This is where we need resilience...

10. A simple
methodology
could determine
which part of a
house is least
liable to damage
in an earthquake
and what
patterns of
damage
might occur.

11. Can we devise
a strategy to enhance
self-
self-protective behaviour?

12. A scale for damage and personal risk level
Damage level: [1] minimum damage
level:
to walls, fitments and furniture.
walls, furniture.
Personal risk level: prudent
level:
behaviour will minimise risks.
risks.

13. A scale for damage and personal risk level
Damage level: [2] significant damage
level:
to structures, cladding and fitments.
Personal risk level: significant
level:
risk of injury but not of death. .

14. A scale for damage and personal risk level
Damage level: [3] general damage and
level:
collapse of architectural elements.
Personal risk level: significant risk of
level:
injury but relatively low risk of death.

15. A scale for damage and personal risk level
Damage level: [4] serious damage
level:
or partial collapse of building.
Personal risk level: strong risk of
level:
injury and significant risk of death.

16. A scale for damage and personal risk level
Damage level: [5] collapse of
level:
more than 50% of the structure.
Personal risk level: limited and mainly
level:
unpredictable probability of survival.

17. Q E
Poor building Proximity
quality Injuries
to epicentre
Q (low seismic and fault E
resistance) rupture Deaths
Concentration
T of casualties
S
Topographic Sedimentary
T amplification amplification S C
C = f { E,Q,S,T }

18. Building quality and seismic resistance:
• site factors

19. Building quality and seismic resistance:
• building type and materials
[Masonry] [Reinforced concrete]

20. Building quality and seismic resistance:
• plan and elevation of building

21. Building quality and seismic resistance:
• urban form factors
[battering
by
adjacent
buildings]

22. Building quality and seismic resistance:
• mixed construction?
[Stone and
concrete
block]

23. Building quality and seismic resistance:
• state of maintenance

24. Building quality and seismic resistance:
• occupancy factors

25. One needs to investigate the relative
importance of these factors in
different situations
site urban form
factors factors
building type mixed
and materials construction?
plan and
elevation
of building

26. Mid-floor damage to multi-occupancy bldg:
Intertia effect
Interaction = damage
Lack of stiffness in frame
Basal acceleration

27. For example... what is the typical
pattern of seismic failure of Iranian
vernacular housing of any given type?

28. Some possible modes of failure
• basal acceleration
• inertial displacement
• spalling of façade
• torsion
• ejection of
infill masonry
• deformation of
structural nodes
• detachment of
internal stairways

29. In the case of total collapse, little
can be done for the occupants of a
building except urban heavy rescue.
This is up to three times more likely
to be successful if the location
of trapped occupants is known
(e.g. they can attract attention).
attention).

30. An example: the L'Aquila (Italy)
earthquake of 6 April 2009

31. n=202 6-25 deaths 3-5 deaths 1-2 deaths
One or two individuals
No deaths
Clusters
of multiple
deaths
L'Aquila city

32. No deaths:
housing stock was
in relatively good
condition and
damage was limited
Damage/risk
scale: 1-2
1-

33. One or two individuals:
people rushed outside
and were killed by
falling masonry
Damage/risk
scale: 3-4
3-

34. ... or in
the collapse
of stairwells.

35. Clusters of
multiple deaths:
spectacular collapses
of multi-occupancy
multi-
buildings with up
to 25 deaths each:
topographic
amplification was an
additional factor.
factor.
Damage/risk
scale: 5

36. Unexpected earthquake
Mild Severe Catastrophic
impact impact impact
Very Fall of
Partial Total
limited heavy
collapse collapse
damage objects
Remain Seek
Seek in situ potential
place of Rush cavity
refuge outside
Lightly Seriously
Uninjured Killed
injured injured
Absolute immobility Frantic egress

37. Earthquake scenario
• magnitude range
• maximum accelerations
• recurrence intervals, etc.
Seismic
performance
of buildings
• modes of failure
• typologies of damage
Risk factors
• behaviour of building occupants
during earthquakes
• effectiveness of
search and rescue

38. Models of typical
vernacular housing
building types
Analysis of
characteristic
failure modes
Determination
of appropriate
crisis behaviour
Education and
training of
households
Culture of
protection
and resilience

39. Resilience against earthquakes:
Ten suggestions for action

40. Tell people what to do in an earthquake.

41. Develop urban search and
rescue capacity on site.

42. Reduce non-structural as
non-
well as structural hazards.

43. Plan flexibly.

44. Create networks.

45. Encourage governance.

46. Adapt and disseminate good practice.

47. Ensure that Disaster Risk Reduction
(DRR) programmes are sustainable

48. Create a strategy for recovering
from the next disaster.

49. Create a culture of resilience
against disasters.

50. ...and avoid the
myth of panic:
it should not be
treated as a
relevant factor
in emergency
planning

51. Thank you
for your
attention!
david.alexander@grforum.org
emergency-planning.blogspot.com
This presentation can be downloaded from:-
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