Not my comments, but interesting. I cut and pasted this from a bike forum I frequent. Same with the pics.
Thanks Jeff.
Looked it over more carefully and it was actually the girders that were going out of plane. Which would cause allot of undue stress to the main truss. They gave many examples of work they have had to do on the bridge because of the out of plane girders, like drilling holes and refurburshing parts of the on and off ramp to releive stress and re solidify the main truss.
Also it seems like many of the joints were welded, which is not a perferred method compared to rivets or bolts, including in salt heavy enviroments.There where worried about the "high state of corrosiveness" on the joints between the girders and the trusses especially on the east side main truss and south side ramp.
Another telling thing in the report is low grade it got for it's redundancy. Basically all structures have fail safes. If one beam goes the other are able to supoort the new stress. The more fail safes the better the redundacy. This bridge, by definition, had no or little redundacy. Which would mean that if one part of the bridge would fail in any way, not just collapsing, it would shift the new stresses to parts of the brindge that were not able to handle it, those parts would fail and so on and well then the end result would be the bridge would collapse as a whole.
I would be, after reading this report, not a bit surprised that the report will come out about the bridges structure being compromised by shape the bridge was in structurally, mixed with a overload of traffic on one lane and the poor redundacy the design of the bridge portrayed.
Sorry about get into this the way I have. It is part of my job to define structural problems. On a much smaller scale then a bridge, but regardless.
I do not want to take away anything about the seriousness of this event and I do realize all the analyzing of data does not make this any less of a horrible diasaster.
My heart and prayers go out to those people. Keep safe
