Chicago balcony collapse clearly structural failure

Published Sunday, July 6, 2003

Editor, the Tribune: The Chicago balcony failure was a needless tragedy, and for the Chicago building commissioner to state - in an AP story in Monday's Tribune - that a structural engineer's preliminary examination determined that the porch was sound is a gross misstatement of fact.

Balconies are designed for a minimum live load of 100 pounds per square foot. Code design minimums are just that - and it is up to the architect or engineer to determine the actual required loading, but never below the code minimum. Now assume the porches were crowded to a point where each person was occupying only 2 square feet - that is not likely to occur, but assume it is possible. Each person would have to have an average weight of more than 200 pounds to exceed the minimum code design of 100 pounds per square foot.

Wood structures are very forgiving since wood has the ability to deflect and deform before failure. Fasteners are different. They can fail without any noticeable sign of overloading, and rapid failure can occur.

After seeing the Chicago porch pictures shown in the Tribune, I can tell you that it was a fastener structural failure and the porch structures were therefore not properly constructed. The Chicago building inspector should have issued a permit for the porches, and the permit should not have been issued without a registered architect or engineer's design. These are the safeguards for buildings and structures for life safety and the very reason for codes and code officials.

951 Covered Bridge Road

http://www.showmenews.com/2003/Jul/20030706Comm006.asp
Columbia Daily Tribune