h artford c ivic c entre a rena r oof c ollapse

HARTFORD CIVIC CENTRE ARENA ROOF

COLLAPSE.

BY GROUP 11: STEPHEN DENT-NEVILLESEÁN KEANEEOIN NORTON

Background

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Background

• Constructed in 1973.

• Housed a basketball court and seating for 5,000 spectators.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Background

• Collapsed on the 18th of January 1978.

•Large snowstorm had caused heavy loading.

• Just 5 hours after a fully attended game.

• No injuries.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

• Used an innovative space frame technology.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

• Used an innovative space frame technology.

• Required using a complicated, expensive and innovative computer program.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

• Used an innovative space frame technology.

• Required using a complicated, expensive and innovative computer program.

• Saved half a million dollars.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

• Roof spanned 91.44m x 109.72m.• 25.29m above the ground.• Completely assembled on the ground.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design and Construction

Proposed Roof:

• Horizontal steel bars with 6.4m spacing.

• 9.14m diagonal members.

• Braced by an intermediate layer.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

There were numerous design flaws associated with the space frame roof.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Insufficient resistance to buckling.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Insufficient resistance to buckling.

• The slenderness ratio of the built up diagonals violated section 1.18.2.4.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Insufficient resistance to buckling.

• The slenderness ratio of the built up diagonals violated section 1.18.2.4 (AISC).

• Another violation was that bolt holes punching through some members exceeded 85% of the gross area.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Dead loads were underestimated by more than 20%.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Dead loads were underestimated by more than 20%.

• Under design led overloading in members:- East & West face exterior top layer compression: 852%

overloaded;

- North & South face exterior compression members: 213% overloaded;

- Interior East-West compression members: 72% overloaded.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Design Flaws

• Dead loads were underestimated by more than 20%.

• Under design led overloading in members:- East & West face exterior top layer compression: 852%

overloaded;

- North & South face exterior compression members: 213% overloaded;

- Interior East-West compression members: 72% overloaded.

• Computer model incorrectly assumed all of the top chords were laterally braced.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

• When built, deflection was twice predicted value. Engineers said such deviations from initial analysis were to be expected.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

• When built, deflection was twice predicted value. Engineers said such deviations from initial analysis were to be expected.

• Unusual deflections were noticed numerous times:– Inspection company;– Subcontractor;– Member of public.

All were ignored.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

• Collapsed in less than 10 seconds.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

• Collapsed in less than 10 seconds.

• Multiple causes given:– Inadequate top chord bracing;– Torsional buckling of compression members;– Faulty weld connection.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Collapse

• Collapsed in less than 10 seconds.

• Multiple causes given:– Inadequate top chord bracing;– Torsional buckling of compression members;– Faulty weld connection.

• All of the above can be attributed to a lack of redundancy.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Conclusions

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Conclusions

• Use of untested, non-conventional design and computer analysis.– Design extremely susceptible to buckling (not analysed by computer).

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Conclusions

• Use of untested, non-conventional design and computer analysis.– Design extremely susceptible to buckling (not analysed by computer).

• Cost cutting led to inadequate inspection and quality control:– No on-site engineer.– Connections weren’t assembled according to the design.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

Conclusions

• Use of untested, non-conventional design and computer analysis.– Design extremely susceptible to buckling (not analysed by computer).

• Cost cutting led to inadequate inspection and quality control:– No on-site engineer.– Connections weren’t assembled according to the design.

• Unexpected deflections were overlooked.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

References

• G. C. Andrews (2008), Canadian Professional Engineering and Geoscience: Practice and Ethics.

• Martin, Rachel, and Delatte, Norbert J. (1999), Another Look at Hartford Civic Center Coliseum Collapse.

• Norbert J. Delatte, Beyond failure: forensic case studies for civil engineers.

• Levy, Matthys and Salvadori, Mario (1992), Why Buildings Fall Down: How Structures Fail.

• Salvadori, Mario, Why Buildings Stand up.

21/10/2011 Hartford Civic Centre Roof Collapse Group 11

HARTFORD CIVIC CENTRE ARENA ROOF

COLLAPSE.Group 11: Stephen Dent-Neville

Sean KeaneEoin Norton