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
BACKGROUND
INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING
EARTHQUAKES
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT (SURFACE FAULTING & GROUND
FAILURE)
IRREGULARITIES IN ELEVATION AND PLAN
TSUNAMI WAVE RUNUP
LACK OF DETAILING AND POOR CONSTRUCTION MATERIALS
LACK OF ATTENTION TO NON-STRUCTURAL ELEMENTS
CAUSES OF DAMAGE
CASE HISTORIES
BUILDING ELEVATIONS
• FACT: Unnecessary FACT: Unnecessary horizontal and vertical horizontal and vertical changes in symmetry, mass, changes in symmetry, mass, and stiffness will increase a and stiffness will increase a building’s vulnerability to building’s vulnerability to strong ground shakingstrong ground shaking. .
FACT: UNUSUAL BUILDINGS ARE LIKELY TO BE MORE
VULNERABLE IN AN EARTHQUAKE
A CHURCH: REYKJAVEK, ICELAND
ATLANTIS HOTEL: DUBAI, UAE
EMP MUSEUM: SEATTLE, WASHINGTON (USA)
A LIBRARY: KANSAS CITY, MISSOURI (USA)
A HOTEL: PYONGYANG, NORTH KOREA
“THE GHERKIN,” AN OFFICE BUILDING: LONDON
SKY CITY (2,749 FEET--NOT YET FINISHED) : CHANGSHA, CHINA
REGULARITY IN A BUILDING’S ELEVATION REDUCES ITS
VULNERABILITY TO STRONG GROUND SHAKING
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
1-21-2
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
None, if attention given to foundation and non-structural elements. Rocking may crack foundation and structure. X-Cracks around windows.
BUILDING ELEVATION
BoxBox
DAMAGED HOUSE:CHINA
ASYMMETRY AND LATERAL CHANGES: CHINA
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
11
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
None, if attention given to foundation and non structural elements. Rocking may crack foundation.
BUILDING ELEVATION
PyramidPyramid
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
4 - 64 - 6
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Top heavy, asymmetrical structure may fail at foundation due to rocking and overturning.
BUILDING ELEVATION
Inverted PyramidInverted Pyramid
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
5 - 65 - 6
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Asymmetry and horizontal transition in mass, stiffness and damping may cause failure where lower and upper structures join.
BUILDING ELEVATION
““L”- Shaped L”- Shaped BuildingBuilding
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
3 - 53 - 5
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Vertical transition and asymmetry may cause failure where lower part is attached to tower.
BUILDING ELEVATION
Inverted “T”Inverted “T”
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
2 - 32 - 3
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Vertical transition in mass, stiffness, and damping may cause failure at foundation and transition points at each floor.
BUILDING ELEVATION
Multiple SetbacksMultiple Setbacks
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
4 - 54 - 5
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Top heavy asymmetrical structure may fail at transition point and foundation due to rocking and overturning.
BUILDING ELEVATION
OverhangOverhang
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
6 - 76 - 7
ANALYSIS OF VULNERABILITY
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
Partial “Soft” StoryPartial “Soft” Story
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
8 - 108 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Vertical transitions in mass and stiffness may cause failure on transition points between first and second floors.
BUILDING ELEVATION
““Soft” First FloorSoft” First Floor
THE TYPICAL SOFT-STOREY BUILDING IN TURKEY
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 109 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transitions in mass and stiffness may cause failure at transition points and possible overturning.
BUILDING ELEVATION
Combination of Combination of “Soft” Story and “Soft” Story and
OverhangOverhang
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
1010
ANALYSIS OF VULNERABILITY
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 on Building on Sloping GroundSloping Ground
SOFT STORY BUILDING ON SLOPING GROUND: CHINA TRIGGERED LANDSLIDES
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
8 - 98 - 9
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transition in stiffness and cause failure of individual members.
BUILDING ELEVATION
Theaters and Theaters and Assembly HallsAssembly Halls
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
9 - 109 - 10
ANALYSIS OF VULNERABILITY
LOCATIONS OF POTENTIAL FAILURE
Horizontal and vertical transition in mass and stiffness may cause failure columns.
BUILDING ELEVATION
Sports StadiumsSports Stadiums
SIMPLICITY IN A BUILDING’S FLOOR PLAN REDUCES ITS
VULNERABILITY TO STRONG GROUND SHAKING
BUILDING FLOOR PLANS
• FACTFACT: CHANGING FLOOR PLANS FROM SIMPLE TO COMPLEX AND FROM SYMMETRICAL TO ASYMMETRICAL WILL INCREASE A BUILDING’S VULNERABILITY TO GROUND SHAKING.
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
11
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
None, if symmetrical layout maintained.
FLOOR PLAN
BoxBox
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
2 - 42 - 4
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Differences in length and width will cause differences in strength, differential movement, and possible overturning.
FLOOR PLAN
RectangleRectangle
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
2 - 42 - 4
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Asymmetry will cause torsion and enhance damage at corners.
FLOOR PLAN
Street CornerStreet Corner
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
5 - 105 - 10
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Asymmetry will enhance damage at corner regions.
FLOOR PLAN
““U” - ShapeU” - Shape
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
44
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Open space in center reduces resistance and enhance damage at corner regions.
FLOOR PLAN
Courtyard in CornerCourtyard in Corner
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
88
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Asymmetry will cause torsion and enhance damage at intersection and corners.
FLOOR PLAN
““L” - ShapeL” - Shape
TORSION: CHINA
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
5 - 75 - 7
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Directional variation in stiffness will enhance damage at intersecting corner.
FLOOR PLAN
““H” - ShapeH” - Shape
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
8 - 108 - 10
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Asymmetry and directional variation in stiffness will enhance torsion and damage at intersecting.
FLOOR PLAN
Complex Floor PlanComplex Floor Plan
RELATIVE VULERABILITY
[1 (Best) to 10 (Worst)]
5- 95- 9
ANALYSIS OF VULNERABILITY
POTENTIAL PROBLEMS
Asymmetry and irregularities will cause torsion and enhance damage along boundaries and at corners.
FLOOR PLAN
Curved PlanCurved Plan
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