unusual architectural design of buildings will increase their vulnerability in earthquakes

SKY CITY (2,749 FEET--NOT YET FINISHED) : CHANGSHA, CHINA

UNUSUAL BUILDINGS AND VULNERABILITY IN

EARTHQUAKES

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 horizontal and vertical changes in symmetry, mass, and stiffness will increase a building’s vulnerability to strong 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

REGULARITY IN A BUILDING’S ELEVATION REDUCES ITS

VULNERABILITY TO STRONG GROUND SHAKING

RELATIVE VULERABILITY

[1 (Best) to 10 (Worst)]

1-2

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

Box

DAMAGED HOUSE:CHINA

ASYMMETRY AND LATERAL CHANGES: CHINA



1



None, if attention given to foundation and non structural elements. Rocking may crack foundation.

BUILDING ELEVATION

Pyramid



4 - 6



Top heavy, asymmetrical structure may fail at foundation due to rocking and overturning.

BUILDING ELEVATION

Inverted Pyramid



5 - 6



Asymmetry and horizontal transition in mass, stiffness and damping may cause failure where lower and upper structures join.

BUILDING ELEVATION

“L”- Shaped Building



3 - 5



Vertical transition and asymmetry may cause failure where lower part is attached to tower.

BUILDING ELEVATION

Inverted “T”



2 - 3



Vertical transition in mass, stiffness, and damping may cause failure at foundation and transition points at each floor.

BUILDING ELEVATION

Multiple Setbacks



4 - 5



Top heavy asymmetrical structure may fail at transition point and foundation due to rocking and overturning.

BUILDING ELEVATION

Overhang



6 - 7



Horizontal and vertical transitions in mass and stiffness may cause failure on soft side of first floor; rocking and overturning.

BUILDING ELEVATION

Partial “Soft” Story



8 - 10



Vertical transitions in mass and stiffness may cause failure on transition points between first and second floors.

BUILDING ELEVATION

“Soft” First Floor

THE TYPICAL SOFT-STOREY BUILDING IN TURKEY



9 - 10



Horizontal and vertical transitions in mass and stiffness may cause failure at transition points and possible overturning.

BUILDING ELEVATION

Combination of “Soft” Story and

Overhang



10



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 Sloping Ground

SOFT STORY BUILDING ON SLOPING GROUND: CHINA TRIGGERED LANDSLIDES



8 - 9



Horizontal and vertical transition in stiffness and cause failure of individual members.

BUILDING ELEVATION

Theaters and Assembly Halls



9 - 10



Horizontal and vertical transition in mass and stiffness may cause failure columns.

BUILDING ELEVATION

Sports Stadiums

SIMPLICITY IN A BUILDING’S FLOOR PLAN REDUCES ITS

VULNERABILITY TO STRONG GROUND SHAKING

BUILDING FLOOR PLANS

• FACT: CHANGING FLOOR PLANS FROM SIMPLE TO COMPLEX AND FROM SYMMETRICAL TO ASYMMETRICAL WILL INCREASE A BUILDING’S VULNERABILITY TO GROUND SHAKING.



1


POTENTIAL PROBLEMS

None, if symmetrical layout maintained.

FLOOR PLAN

Box



2 - 4


POTENTIAL PROBLEMS

Differences in length and width will cause differences in strength, differential movement, and possible overturning.

FLOOR PLAN

Rectangle



2 - 4


POTENTIAL PROBLEMS

Asymmetry will cause torsion and enhance damage at corners.

FLOOR PLAN

Street Corner



5 - 10


POTENTIAL PROBLEMS

Asymmetry will enhance damage at corner regions.

FLOOR PLAN

“U” - Shape



4


POTENTIAL PROBLEMS

Open space in center reduces resistance and enhance damage at corner regions.

FLOOR PLAN

Courtyard in Corner



8


POTENTIAL PROBLEMS

Asymmetry will cause torsion and enhance damage at intersection and corners.

FLOOR PLAN

“L” - Shape

TORSION: CHINA



5 - 7


POTENTIAL PROBLEMS

Directional variation in stiffness will enhance damage at intersecting corner.

FLOOR PLAN

“H” - Shape



8 - 10


POTENTIAL PROBLEMS

Asymmetry and directional variation in stiffness will enhance torsion and damage at intersecting.

FLOOR PLAN

Complex Floor Plan



5- 9


POTENTIAL PROBLEMS

Asymmetry and irregularities will cause torsion and enhance damage along boundaries and at corners.

FLOOR PLAN

Curved Plan

unusual architectural design of buildings will increase their vulnerability in earthquakes

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