EERI Student Chapter Rice University Topic 1 Basic Earthquake Engineering Concepts What happens during an Earthquake Ground motion characteristics How long How strong Frequency content ID: 698283
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Undergraduate seismic design competition -2013
EERI Student Chapter – Rice University
Topic #1: Basic Earthquake Engineering ConceptsSlide2
What happens during an Earthquake?
Ground motion characteristics:How long?
How strong?
Frequency content?
Building response:Strong vibrations Large stresses and strainsLocal Failure Many local Failures Progressive Collapse Building CollapseSlide3
Basic Design Concepts #1
Avoid ‘soft-story’ ground floors! Maintain uniformity throughout height Provides braces at all
storeys
‘Soft-story’ formationSlide4
Basic Design Concepts #2
Avoid ‘soft-story’ upper floors!Maintain uniformity throughout height Provides braces at all storeys
‘Soft-story’ formationSlide5
Basic Design Concepts #3
Avoid non-symmetric bracing!
Bracings
Building Front View
Building Top View
Non-symmetric Bracing
Symmetric BracingSlide6
Basic Design Concepts #4
Avoid discontinuities is stiffness and resistanceSlide7
Basic Design Concepts #5
Provide slender structural walls!Structural walls along principal directions Be as symmetric as possible Slide8
Basic Design Concepts #6
Avoid short column!Short columns often fail in shearSlide9
Basic Design Concepts #7
Protect your foundations!Slide10
Basic Design Concepts #8
Strong column weak beam theory!Slide11
Basic Design Concepts #9
Avoid resonance!We will need this at the analytical/computer model building stageWe have to check and confirm that dominant earthquake frequency and building frequency are different to avoid resonance
Mention this point in the proposal!!Slide12
Basic Design Concepts #9
Bracings and damping devices Will be covered tomorrow!Slide13
Topic #2:
Structural Systems for Tall BuildingsSlide14
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Tall Buildings
Skyscraper is the greatest architectural invention of America
Steel frame structure for the 1
st time used in England in 1792Slide15
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Problem of Size
Increase in size: reduction in strength
The Euler buckling of the columns
Cannot directly employ the existing models and magnify themSlide16
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Imhotep to Fazlur Rahman
Khan
"Einstein of structural engineering"
His "tube concept," using all the exterior wall perimeter structure of a building to simulate a thin-walled tube, revolutionized tall building designSlide17
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Structural SystemsSlide18
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Example of Bundle TubesSlide19
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Truss Tube
Mode shapesSlide20
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Connections
Optimum seismic connectionSlide21
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Failure MechanismSlide22
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Failure Mechanism