Transcript Kemper Roof Pres.ppt

The Kemper Arena Roof Collapse
Group 5
Introduction
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History
What happened
Technical factors
Human factors
Summary
History
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Built in 1973 as a
basketball arena
Capacity of 17,000
Contemporay
design
AIA conference on
day preceeding
disaster
What happened
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June 1979 roof collapse
70 mph storm
Pooling of water on roof
4000 m2 of roof collapsed
Rapid increase in air pressure
Technical factors
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Steel trusses
supported RC roof
4 A490 bolts
Bolts subjected to
24,000 oscillations
Caused metal to
fatigue
Bolts failed at 1/3
capacity
Technical factors
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Temporary reservoir on roof
Drainage inadequate
8 10” drains
“Ponding” effect caused instability
Bolts failed in one hanger
Disproportionate collapse
Technical factors
Human factors
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Poor bolt selection
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Inadequate drainage design
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High strength, low ductility
Neglected metal fatigue
City codes required 55 drains
One in 10 year storm
Insufficient hangers
Summary
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Reasons for collapse
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Bolt failure
Ponding effect
Disproportionate collapse
Lessons to be learned
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Dynamic loading on bolts
Building standards
Better load distribution