As a long time Structural Engineer, I read STRUCTURE magazine regularly, and appreciate the selection of articles.
Upon seeing the cover of the January 2013 issue, I was compelled to share some of my experience.
I believe that a significant number of failures can be attributed to the structural design engineer for not having, or insisting on, the opportunity to inspect his/her design in the field before it is covered up or hidden from view. The person who designed the reinforcing, for example, can tell more quickly than almost anyone if it is the same size and placement as he intended.
In the old days, when engineers were a sub-contract to the architect, there was no budget for the engineer’s on-site inspection. I used to go out on my own, without pay, to inspect my design. As often as 50 percent of the time, I found things that needed to be corrected which I documented in a report that went to my Partners, the Owner, the Contractor and the City Inspector.
I do not know whether these instances were ignorance or fraud, intentional or accidental. In some cases, failure would have happened if it had not been discovered and corrected.
I’ve heard all types of excuses, including:
- “They weren’t needed.” (50% of the plug welds on a steel deck)
- “I never had to do it that way before.”
- “I’ve always done it that way.”
- “I couldn’t understand why it was necessary.”
- “We have never had to do engineered drawings before, and I don’t know how to read them.”
- “My supervisor said we could save money if we omitted every other bar (or spaced them farther apart).”
Chapter 17 of the International Building Code allows us to “invite ourselves” to the field to “Observe’ our design. On the front page of my set of plans, I have a separate section entitled “Structural Observation”; here is where I list the items I wish to look at before they are covered up or hidden from view. It’s worth the trip, education, and good public relations.
Sincerely,
James D. Leach, S.E.
California Registered Structural Engineer