UNUSUAL BUILDINGS AND VULNERABILITY IN EARTHQUAKES

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UNUSUAL BUILDINGS AND VULNERABILITY IN
EARTHQUAKES
Walter Hays, Global Alliance for Disaster
Reduction, Vienna, Virginia, USA 
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BACKGROUND
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CAUSES OF DAMAGE
INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT (SURFACE FAULTING GROUND
FAILURE)
IRREGULARITIES IN ELEVATION AND PLAN
EARTHQUAKES
TSUNAMI WAVE RUNUP
CASE HISTORIES
LACK OF DETAILING AND POOR CONSTRUCTION
MATERIALS
LACK OF ATTENTION TO
NON-STRUCTURAL ELEMENTS
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BUILDING ELEVATIONS

• FACT Unnecessary horizontal and vertical changes
  in symmetry, mass, and stiffness will increase a
  buildings vulnerability to strong ground
  shaking.

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FACT UNUSUAL BUILDINGS ARE LIKELY TO BE MORE
VULNERABLE IN AN EARTHQUAKE
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A CHURCH REYKJAVEK, ICELAND
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ATLANTIS HOTEL DUBAI, UAE
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EMP MUSEUM SEATTLE, WASHINGTON (USA)
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A LIBRARY KANSAS CITY, MISSOURI (USA)
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A HOTEL PYONGYANG, NORTH KOREA
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THE GHERKIN, AN OFFICE BUILDING LONDON
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SKY CITY (2,749 FEET--NOT YET FINISHED)
CHANGSHA, CHINA
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REGULARITY IN A BUILDINGS ELEVATION REDUCES ITS
VULNERABILITY TO STRONG GROUND SHAKING
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
None, if attention given to foundation and
non-structural elements. Rocking may crack
foundation and structure. X-Cracks around windows.
1-2
Box
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DAMAGED HOUSECHINA
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ASYMmETRY and lateral changes CHINA
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
None, if attention given to foundation and non
structural elements. Rocking may crack
foundation.
1
Pyramid
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Top heavy, asymmetrical structure may fail at
foundation due to rocking and overturning.
4 - 6
Inverted Pyramid
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry and horizontal transition in mass,
stiffness and damping may cause failure where
lower and upper structures join.
5 - 6
L- Shaped Building
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Vertical transition and asymmetry may cause
failure where lower part is attached to tower.
3 - 5
Inverted T
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Vertical transition in mass, stiffness, and
damping may cause failure at foundation and
transition points at each floor.
2 - 3
Multiple Setbacks
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Top heavy asymmetrical structure may fail at
transition point and foundation due to rocking
and overturning.
4 - 5
Overhang
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Horizontal and vertical transitions in mass and
stiffness may cause failure on soft side of first
floor rocking and overturning.
6 - 7
Partial Soft Story
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Vertical transitions in mass and stiffness may
cause failure on transition points between first
and second floors.
8 - 10
Soft First Floor
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THE TYPICAL SOFT-STOREY BUILDING IN TURKEY
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Horizontal and vertical transitions in mass and
stiffness may cause failure at transition points
and possible overturning.
9 - 10
Combination of Soft Story and Overhang
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Horizontal transition in stiffness of soft story
columns may cause failure of columns at
foundation and/or contact points with structure.
10
Building on Sloping Ground
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SOFT STORY BUILDING ON SLOPING GROUND CHINA
TRIGGERED LANDSLIDES
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Horizontal and vertical transition in stiffness
and cause failure of individual members.
8 - 9
Theaters and Assembly Halls
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ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
BUILDING ELEVATION
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Horizontal and vertical transition in mass and
stiffness may cause failure columns.
9 - 10
Sports Stadiums
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SIMPLICITY IN A BUILDINGS FLOOR PLAN REDUCES ITS
VULNERABILITY TO STRONG GROUND SHAKING
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BUILDING FLOOR PLANS

• FACT CHANGING FLOOR PLANS FROM SIMPLE TO
  COMPLEX AND FROM SYMMETRICAL TO ASYMMETRICAL WILL
  INCREASE A BUILDINGS VULNERABILITY TO GROUND
  SHAKING.

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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
None, if symmetrical layout maintained.
1
Box
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Differences in length and width will cause
differences in strength, differential movement,
and possible overturning.
2 - 4
Rectangle
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry will cause torsion and enhance damage
at corners.
2 - 4
Street Corner
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry will enhance damage at corner regions.
5 - 10
U - Shape
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Open space in center reduces resistance and
enhance damage at corner regions.
4
Courtyard in Corner
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry will cause torsion and enhance damage
at intersection and corners.
8
L - Shape
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torsion CHINA
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Directional variation in stiffness will enhance
damage at intersecting corner.
5 - 7
H - Shape
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry and directional variation in stiffness
will enhance torsion and damage at intersecting.
8 - 10
Complex Floor Plan
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ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
FLOOR PLAN
RELATIVE VULERABILITY 1 (Best) to 10
(Worst)
Asymmetry and irregularities will cause torsion
and enhance damage along boundaries and at
corners.
5- 9
Curved Plan