Hartford civic centre
arena roof collapse
Presentation
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Introduction
Organisation of the team
Roof design
Indications of failure
Reasons for failure
Conclusions
Location
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Connecticut, USA
The arena
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Built in 1975
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Sports and convention complex
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Large capacity
Team behind the structure
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Well known architect – Vincent Kling
Engineers – Fraoli, Blum & Yesselman (FBY)
Construction – Bethlehem Steel Company
Inspection – Gulick Henderson
Many sub-contractors
Coordinated by a construction manager
Roof structure – an overview
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FBY proposed a unique design
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Space frame measuring 91m x 110m
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Save $500,000 but…required complex analysis
Roof structure - pyramidal truss
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Top & bottom square grids
Diagonals connecting them
Roof structure - bracing
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Top horizontal bars
Main diagonals
Roof structure – 3 unusual features
1) Top horizontal bars – “cross” cross-section
2) Horizontal bars and diagonal bars intersected at
different points → bending stresses
Roof structure – 3 unusual features
3) Roof supported by 4 large pylon legs inside
edges of frame
Prior to failure
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During assembly – excessive deflection at nodes
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Members of the public & politicians concerned
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In position – deflection at centre twice expected
Failure occurs
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Heavy snowfall
Timing – good fortune
Investigation into the collapse
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Actual loads on roof at failure < total load
assumed in design
Along frame edges, buckling of top bars not
prevented
Investigation into the collapse
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Actual loads on roof at failure < total load
assumed in design
Along frame edges, buckling of top bars not
prevented
Computer analysis of failure
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Tells us what happened after first bar buckled
→ “progressive collapse”
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Need for redundancy
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5000 members in roof – 50 more would have
prevented buckling
Other contributing factors proposed:
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Torsional buckling
Differences between design and as-built
Violations of American Institute of Steel
Construction (AISC) code
Conclusions
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Sound engineering judgement and ethics
Make use of redundancy
Computer analysis has limitations – buckling not
considered
Peer review
Responsibility
Final outcome
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Out of court settlement six years later
Not made clear who had responsibility for
structural integrity of project
Group 16
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Antoine Gaudin
Brendan McCabe
Eoghan MacTighearnáin
Andrew Lochaden