Well then, now that there's further preliminary official reports out I feel there's enough information for me to comment without indiscriminately disparaging the parties involved or without criticizing without sufficient knowledge (for me personally; you folks carry on, I enjoy reading all these comments. I'm being deliberately conservative in not commenting until now given how much public scrutiny this failure has received).
Knowing nothing else, those cracks should have junked the bridge IMO. A flexural, shrinkage, or other crack from casting, moving, or in-service stresses should be partial depth cracks of a hairline nature
at worst. Plus, per most standards I've had to design pedestrian bridges to, and per the PCI design handbook which I assume applied to this project, tensile stresses that exceed the modulus of rupture and cause cracking on exposed members should be prevented during moving.
Without mentioning the likely design errors by the EOR, this is troubling from all aspects of the project.
I designed a slab a few years back to span over a trench at a farm. I goofed and forgot to check lifting and handling stresses on the panels for tensile rupture. The panel was completely safe and serviceable but did not meet PCI standards due to these hairline cracks that formed after lifting.
The cracks were only 0.010" wide. This is standard industry practice for precast items where I work, this rejection was done on my call with no oversight.
If my cracked panel was a state project then this would have been similarly been rejected right away by the state inspector and I wouldn't have been able to brush it off even if I wanted to. Hairline cracks are not permitted without repair or at least a non-conformance report in our bridge work. I can only imagine that on this bridge there were government inspectors or at least some third-party there inspecting for the owner. This should have instantly been something that the owner and/or the governmental organization overseeing it should have been made aware of, and required a written report from the contractor/engineer on how these cracks should be addressed.
I can't believe that any third-party inspector or overseeing engineer stood by and allowed this to proceed. In my opinion, unless these were hidden from them, they need to share some liability in allowing this to proceed. The engineer should have been required to submit documentation showing that there was no structural issue, that this could be repaired, and that the bridge was not unsafe. I can't see how any of that was done, as it should have identified the impending failure and no work should have been done with traffic under the structure. If these cracks were hidden or their effects minimized in what the third-party inspectors saw then so be it; but assuming they were in the loop I'm very curious to hear what the other officials involved in this project have to say.
I wonder who was pushing for this bridge to go in more; the owner, the governmental organizations, or the EOR/contractor. Sounds like everyone was more than willing to turn a blind eye to this.
Regarding the cracks shown; those are not simple hairline cracks from a bad move of the bridge. That is a failure of the bridge. This is not looking favorable to any involved. I agree with these above who are wondering who gave the "okay" for this and who else was in the background screaming for this to be addressed properly. Could this be the challenger disaster all over again?
Ian Riley, PE, SE
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
