1. Group 16 Ian Bray Aodhin Mc Bride John McElwee

2. Background Collapsed January 18 th 1978 – 5 years after construction Large snowstorm caused heavy loading Arena was not in use when roof collapsed No injuries or fatalities

3. Structural Design Fraoli, Blum & Yesselman, Engineers were employed to design arena. Engineers used innovative space frame design. Roof spanned 91.44m x 109.72m and at a height of 25.29m above the ground.

5. How was it different? The top layer of this roof did not support the roofing panels. The top horizontal bars did not intersect at the same points Four pylon legs supported the roof. The configuration of the four steel angles did not provide a good resistance to buckling.

6. Saving money and time... used of a state-of-the-art computer analysis to verify the safety of the building. The architect had tried twice to convince the owners to hire a qualified structural engineer for continuous on- site inspection. roof frame was completely assembled on the ground.

7. Warnings of Failure Excessive deflections were noticed on numerous occasions Inspection company Subcontractor Member of the public Each one was ignored

8. Construction Design allowable force ≠ built allowable force Mid point bracing omitted for top layer rods Spacing was double the designed amount Top bars experienced buckling as a result

9. Collapse Unexpected amount of snow Members of top truss buckled Resulted in all members buckling and structural collapse

10. Conclusion Overconfidence in Computer Analysis Roof design extremely susceptible to buckling- not analysed by computer Cut costs but at the expense of the structures stability Connections not assembled according to design No responsibility taken by contractor towards the performance of the project

11. Project Management No overall responsibility for the project No structural engineer hired to inspect the roof frame and connections Subcontractor questioned deflections as it was difficult to connect steel frame, “Deal with the problem or be responsible for delays” A year later, a member of public notified the engineer of his concern at the obvious downward deflection of the roof but was assured, “Everything is fine”

12. Recommendations The computer is only an analytical tool and it is always a good idea to inspect the building against the design criteria If the horizontal and diagonal members intersected at the same place it would have reduced the bending stresses in these members The structure should have been built with more redundancy so the failure of a few members would not cause such a catastrophic collapse

13. Recommendations (cont.) The responsibility of the architects, engineers and construction manager should be well defined There should be one person who ultimately is responsible for the success of the project as a whole. One should re-check design calculations when deformations occur Independent checks on design calculations should be enforced

14. References Rachel Martin, Case study “Hartford Civic Centre Arena Roof Collapse” J. Perf. Constr. Fac. Volume 15, Issue 1, pp. 31-36 (February 2001) ‘Another Look at Hartford Civic Center Coliseum Collapse’. “Structural safety and its quality assurance” By Bruce Ellingwood, Council on Tall Buildings and Urban Habitat. Committee 9A/10, Structural Engineering Institute