They said the calculations were wrong. The error may have been in one of several stages—design, drafting, etc., I can’t remember exactly. The calculations were not reviewed after the point at which the error occured.
That's gonna hurt.
Speaking as a retired design engineer.... 'those kind of things damage engineering careers'.
Question for any structural engineers: Isn't it SOP to load test any new designs?
I just don’t believe this conclusion. It is too convenient. It lets everyone alive off the hook. I have gone through a number of AISC code revisions. EVERY one of them increased the thicknesses (and/or lowered the allowable stress) when compared to the previous one at least somewhere in the code. Over 40 years, they add up to quite a difference.
So if they were comparing the as-built sizes with the current code, they are guaranteed to find a “flaw” in the design. In addition, the number of lanes was increased at sometime between the original building and the collapse. That was bound to increase loads. Who approved that decision? Again, checking calculations with the current number of lanes is guaranteed to find a flaw.
In addition, the inspection report showed that there were NUMEROUS cracks in those very gusset plates and many of them were only half the original thickness because of serious corrosion. That was all noted in the reports — and ignored. If they intend to ignore reports, why bother even having them.
This is a whitewash. A coverup.