lessons learned from past notable disasters mexico part 3b: earthquake vulnerability of buildings...
TRANSCRIPT
LESSONS LEARNED FROM PAST NOTABLE DISASTERS
MEXICOPART 3B: EARTHQUAKE
VULNERABILITY OF BUILDINGS
Walter Hays, Global Alliance for Disaster Reduction, Vienna,
Virginia, USA
MEXICO
MEXICO IS ON THE PACIFIC RIM WHERE A LARGE FRACTION OF THE GLOBAL SEISMICITY OCCURS
NATURAL HAZARDS THAT HAVE CAUSED NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN MEXICODISASTERS IN MEXICO
NATURAL HAZARDS THAT HAVE CAUSED NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN MEXICODISASTERS IN MEXICO
FLOODS
SEVERE WINDSTORMS
EARTHQUAKES
VOLCANIC ERUPTIONS
ENVIRONMENTAL CHANGE
GLOBAL CLIMATE CHANGE
HIGH BENEFIT/COST FROM BECOMING DISASTER RESILIENT
HIGH BENEFIT/COST FROM BECOMING DISASTER RESILIENT
GOAL: PROTECT PEOPLE GOAL: PROTECT PEOPLE AND COMMUNITIESAND COMMUNITIES
GOAL: PROTECT PEOPLE GOAL: PROTECT PEOPLE AND COMMUNITIESAND COMMUNITIES
MEXICO EXPERIENCED A M8.1 SUBDUCTION ZONE QUAKE IN 1985
BUILDING VULNERABILITY WAS (AND STILL IS) A
MAJOR FACTOR IN MEXICO’S LOSSES IN 1985
Mexico’s building stock, like the building stock of all countries,
has vulnerabilities as a result of
irregularities in elevation and plan, construction materials,
and the underlying soil
HAZARDSHAZARDSHAZARDSHAZARDS
ELEMENTS OF EARTHQUAKE ELEMENTS OF EARTHQUAKE RISK RISK
ELEMENTS OF EARTHQUAKE ELEMENTS OF EARTHQUAKE RISK RISK
EXPOSUREEXPOSUREEXPOSUREEXPOSURE
VULNERABILITYVULNERABILITYVULNERABILITYVULNERABILITY LOCATIONLOCATIONLOCATIONLOCATION
RISKRISKRISKRISK
EARTHQUAKEHAZARD MODEL
EARTHQUAKEHAZARD MODEL
SEISMICITYSEISMICITY TECTONICSETTING &
FAULTS
TECTONICSETTING &
FAULTS
TECTONIC DEFORMATION
EARTHQUAKE
TSUNAMI
GROUND
SHAKING
FAULT RUPTURE
FOUNDATION FAILURE
SITE AMPLIFICATION
LIQUEFACTION
LANDSLIDES
AFTERSHOCKS
SEICHE
DAMAGE/LOSSDAMAGE/LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/LOSSDAMAGE/LOSS
EXPOSUREMODEL
EXPOSUREMODEL
LOCATION OF STRUCTURE
LOCATION OF STRUCTURE
IMPORTANCE AND VALUE OF
STRUCTURE AND CONTENTS
IMPORTANCE AND VALUE OF
STRUCTURE AND CONTENTS
VULNERABILITYMODEL
VULNERABILITYMODEL
QUALITY OF DESIGN AND
CONSTRUCTION
QUALITY OF DESIGN AND
CONSTRUCTION
ADEQUACY OF LATERAL-FORCE
RESISTING SYSTEM
ADEQUACY OF LATERAL-FORCE
RESISTING SYSTEM
UNREINFO
RCED MASO
NRY, BRIC
K OR S
TONE
REINFORCED C
ONCRETE WIT
H UNREIN
FORCED WALLS
INTENSITYINTENSITY
REINFORCED CONCRETE WITH REINFORCEDWALLS
STEEL FRAME
ALL METAL & WOOD FRAME
VV VIVI VIIVII VIIIVIII IXIX
3535
3030
2525
2020
1515
1010
55
00
MEA
N D
AM
AG
E R
ATIO
,
%
M
EA
N D
AM
AG
E R
ATIO
,
%
O
F R
EPLA
CE
MEN
T V
ALU
EO
F R
EPLA
CE
MEN
T V
ALU
E
CONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND
SHAKING
CONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND
SHAKING
INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING
EARTHQUAKESEARTHQUAKES
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT (SURFACE FAULTING & GROUND
FAILURE)
IRREGULARITIES IN ELEVATION AND PLAN
FIRE FOLLOWING RUPTURE OF UTILITIES
LACK OF DETAILING AND CONSTRUCTION MATERIALS
INATTENTION TO NON-STRUCTURAL ELEMENTS
CAUSES OF DAMAGE
CAUSES OF DAMAGE
“DISASTER LABORATORIES”
“DISASTER LABORATORIES”
MEXICO CITY HAS SOFT SOILS THAT AMPLIFY GROUND SHAKING
MEXICO CITY HAS SOFT SOILS THAT AMPLIFY GROUND SHAKING
MEXICO CITY HAS VULNERABLE SHORT BUILDINGS
MEXICO CITY HAS VULNERABLE TALL BUILDINGS
POLICY POLICY ADOPTIONADOPTION
POLICY POLICY ADOPTIONADOPTION
RISK ASSESSMENT
• VULNERABILITYVULNERABILITY
• EXPOSUREEXPOSURE
• EVENTEVENT
POLICY ASSESSMENT
• COSTCOST
• BENEFITBENEFIT
•CONSEQUENCESCONSEQUENCES
REDUCING BUILDING VULNERABILITY REDUCING BUILDING VULNERABILITY REDUCES THE COMMUNITY’S RISKREDUCES THE COMMUNITY’S RISK
AN EARTH-AN EARTH-QUAKEQUAKE
AN EARTH-AN EARTH-QUAKEQUAKE EXPECTED EXPECTED
LOSSLOSS
EXPECTED EXPECTED LOSSLOSS
VULNERABILITY REDUCTION IS A CLASSIC EXAMPLE OF
STRATEGIC COLLABORATION
ACKNOWLEDGMENT: The vulnerability analyses that follow are based on global experience of a major reinsurance company that was shared for the benefit of all countries having buildings at
risk in future earthquakes.
ANALYSIS OF VULNERABILITY DUE TO
IRREGULARITIES IN BUILDING ELEVATIONS
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
1-21-2
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
None, if attention given to foundation and non structural elements. Rocking may crack foundation and structure.
BUILDING ELEVATION
BUILDING ELEVATION
BoxBox
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
11
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
None, if attention given to foundation and non structural elements. Rocking may crack foundation.
BUILDING ELEVATION
BUILDING ELEVATION
PyramidPyramid
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
2 - 32 - 3
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Vertical transition in mass, stiffness, and damping may cause failure at foundation and transition points at each floor.
BUILDING ELEVATION
BUILDING ELEVATION
Multiple SetbacksMultiple Setbacks
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
4 - 64 - 6
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Top heavy, asymmetrical structure may fail at foundation due to rocking and overturning.
BUILDING ELEVATION
BUILDING ELEVATION
Inverted PyramidInverted Pyramid
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
5 - 65 - 6
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Asymmetry and horizontal transition in mass, stiffness and damping may cause failure where lower and upper structures join.
BUILDING ELEVATION
BUILDING ELEVATION
““L”- Shaped L”- Shaped BuildingBuilding
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
3 - 53 - 5
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Vertical transition and asymmetry may cause failure where lower part is attached to tower.
BUILDING ELEVATION
BUILDING ELEVATION
Inverted “T”Inverted “T”
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
4 - 54 - 5
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Top heavy asymmetrical structure may fail at transition point and foundation due to rocking and overturning.
BUILDING ELEVATION
BUILDING ELEVATION
OverhangOverhang
SOFT-STOREY BUILDINGS ARE THE MOST VULNERABLE
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
6 - 76 - 7
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transitions in mass and stiffness may cause failure on soft side of first floor; rocking and overturning.
BUILDING ELEVATION
BUILDING ELEVATION
Partial “Soft” StoryPartial “Soft” Story
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
8 - 108 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Vertical transitions in mass and stiffness may cause failure on transition points between first and second floors.
BUILDING ELEVATION
BUILDING ELEVATION
““Soft” First FloorSoft” First Floor
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 109 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transitions in mass and stiffness may cause failure at transition points and possible overturning.
BUILDING ELEVATION
BUILDING ELEVATION
Combination of Combination of “Soft” Story and “Soft” Story and
OverhangOverhang
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 109 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transition in mass and stiffness may cause failure columns.
BUILDING ELEVATION
BUILDING ELEVATION
Sports StadiumsSports Stadiums
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
1010
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
LOCATIONS OF POTENTIAL FAILURE
Horizontal transition in stiffness of soft story columns may cause failure of columns at foundation and/or contact points with structure.
BUILDING ELEVATION
BUILDING ELEVATION
Building on Building on Sloping GroundSloping Ground
ANALYSIS OF VULNERABILITY DUE TO
IRREGULARITIES IN PLAN
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
11
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
None, if symmetrical layout maintained.
FLOOR PLANFLOOR PLAN
BoxBox
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
2 - 42 - 4
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Differences in length and width will cause differences in strength, differential movement, and possible overturning.
FLOOR PLANFLOOR PLAN
RectangleRectangle
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
2 - 42 - 4
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry will cause torsion and enhance damage at corners.
FLOOR PLANFLOOR PLAN
Street CornerStreet Corner
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
44
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Open space in center reduces resistance and enhance damage at corner regions.
FLOOR PLANFLOOR PLAN
Courtyard in CornerCourtyard in Corner
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
4 - 54 - 5
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry will cause torsion and enhance damage along curved boundary.
FLOOR PLANFLOOR PLAN
TheatersTheaters
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
5 - 105 - 10
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry will enhance damage at corner regions.
FLOOR PLANFLOOR PLAN
““U” - ShapeU” - Shape
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
5 - 75 - 7
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Directional variation in stiffness will enhance damage at intersecting corner.
FLOOR PLANFLOOR PLAN
““H” - ShapeH” - Shape
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
88
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry will cause torsion and enhance damage at intersection and corners.
FLOOR PLANFLOOR PLAN
““L” - ShapeL” - Shape
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
RELATIVE VULERABILITY [1 (Best) to 10 (Worst)]
8 - 108 - 10
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry and directional variation in stiffness will enhance torsion and damage at intersecting.
FLOOR PLANFLOOR PLAN
Complex Floor PlanComplex Floor Plan
ANALYSIS OF VULNERABILITY DUE TO
IRREGULARITIES IN INTERNAL PROPERTIES
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry and discontinuities in strength will cause torsion and concentrate stress around the opening.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Opening in Shear WallOpening in Shear Wall
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry and variable stiffness will cause torsion and cracking/failure at staircase and elevator well.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Opening in Shear WallOpening in Shear Wall
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Variable stiffness will enhance cracking and failure on weaker side of structure.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Shear Wall or Retaining Shear Wall or Retaining Wall on only one sideWall on only one side
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Asymmetry and irregularities will cause torsion and enhance failure at all points of irregularity.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Different or Irregular Different or Irregular Spans; short columnsSpans; short columns
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Vertical transitions in seismic resistance will enhance failure at the “short columns”.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Window Bands Interrupting In-Window Bands Interrupting In-Fill WallsFill Walls
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Vertical transitions in stiffness will enhance failure at the transition points.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Three Story FrameThree Story Frame
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Vertical transitions in mass will enhance cantilever action, overturning moment, and failure at transition points.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Offset ColumnsOffset Columns
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Horizontal transition in depth of foundation will cause rocking and failure at edges.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Irregular FoundationIrregular Foundation
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Discontinuities in mass, stiffness, and damping will be enhanced at all transition points.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Industrial or Commercial FacilityIndustrial or Commercial Facility
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
POTENTIAL PROBLEMS
Top-heavy structures are vulnerable to distant earthquakes and resonance of thick soft soils because of vertical transition in mass.. Rocking, overturning, and foundation failure are enhanced.
INTERNAL PROPERTIES
INTERNAL PROPERTIES
Water TowerWater Tower
DUPONT
EMERGING TECHNOLOGIES FOR REDUCING
VULNERABILITIES IN PLAN AND ELEVATION
EMERGING TECHNOLOGIES FOR REDUCING
VULNERABILITIES IN PLAN AND ELEVATION
EMERGING TECHNOLOGIES EMERGING TECHNOLOGIES
• AUTOMATED CONSTRUCTION EQUIPMEMT
• PREFABRICATION AND MODULARIZATION
• ADVANCED MATERIALS (E.G., COMPOSITES)
• COMPUTER AIDED DESIGN
• PERFORMANCE BASED CODES AND STANDARDS
• ACTIVE AND PASSIVE ENERGY DISSIPATION DEVICES (E.G., BASE ISOLATION)
• REAL-TIME MONITORING AND WARNING SYSTEMS
• COMPUTER AIDED DESIGN
• PERFORMANCE BASED CODES AND STANDARDS
• ACTIVE AND PASSIVE ENERGY DISSIPATION DEVICES (E.G., BASE ISOLATION)
• REAL-TIME MONITORING AND WARNING SYSTEMS