1. H ARTFORD C IVIC C ENTRE A RENA R OOF C OLLAPSE.

2. B Y G ROUP 11: S TEPHEN D ENT -N EVILLE S EÁN K EANE E OIN N ORTON

3. Background 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

4. Background Constructed in 1973. Housed a basketball court and seating for 5,000 spectators. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

5. Background Collapsed on the 18 th of January 1978. Large snowstorm had caused heavy loading. Just 5 hours after a fully attended game. No injuries. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

6. Design and Construction 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

7. Design and Construction Used an innovative space frame technology. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

8. Design and Construction Used an innovative space frame technology. Required using a complicated, expensive and innovative computer program. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

9. Design and Construction Used an innovative space frame technology. Required using a complicated, expensive and innovative computer program. Saved half a million dollars. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

10. Design and Construction Roof spanned 91.44m x 109.72m. 25.29m above the ground. Completely assembled on the ground. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

11. Design and Construction Proposed Roof: Horizontal steel bars with 6.4m spacing. 9.14m diagonal members. Braced by an intermediate layer. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

12. Design Flaws 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

13. Design Flaws There were numerous design flaws associated with the space frame roof. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

14. Design Flaws Insufficient resistance to buckling. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

15. Design Flaws Insufficient resistance to buckling. The slenderness ratio of the built up diagonals violated section 1.18.2.4. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

16. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

17. Design Flaws Dead loads were underestimated by more than 20%. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

18. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

19. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

20. Collapse 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

21. Collapse When built, deflection was twice predicted value. Engineers said such deviations from initial analysis were to be expected. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

22. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

23. Collapse Collapsed in less than 10 seconds. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

24. Collapse Collapsed in less than 10 seconds. Multiple causes given: –Inadequate top chord bracing; –Torsional buckling of compression members; –Faulty weld connection. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

25. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

26. Conclusions 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

27. Conclusions Use of untested, non-conventional design and computer analysis. –Design extremely susceptible to buckling (not analysed by computer). 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

28. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

29. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

30. 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. 21/10/2011Hartford Civic Centre Roof CollapseGroup 11

31. H ARTFORD C IVIC C ENTRE A RENA R OOF C OLLAPSE. Group 11: Stephen Dent-Neville Sean Keane Eoin Norton