[ProtectOurFreedom]

I have no doubt that the truss system they jacked into place was engineered to be self-supporting. But, if it was correctly designed to be self-supporting, then what was the purposed of the tower and stay-cables?

Maybe the bridge was designed to support its own weight (the dead load) with a small safety margin and the tower and stay-cables were to be added later to take the live load (the people crossing the bridge) and add a much greater safety margin. Or perhaps the tower and stay-cables were meant to be largely decorative and add drama.

I’ve never heard of such an approach and, I have to admit, it would be a weird design approach. But this bridge used the “innovative Accelerated Bridge Construction” method developed at the university. Who knows what they were capable of thinking.

[Ambrosia]

My guess is that they were over confident it would have no issues, when stress tested. However, it is common sense to err on the side of caution, and at least stop traffic from going under the bridge during that test! People died from that lack of forethought....sad.

[Scrambler Bob]

But this bridge used the “innovative Accelerated Bridge Construction”
= = =

That means put it up quick, before it falls down!

[BenLurkin]

Hurricanes, supposedly, is why the additional support.

[DiogenesLamp]

I’ve never heard of such an approach and, I have to admit, it would be a weird design approach. But this bridge used the “innovative Accelerated Bridge Construction” method developed at the university. Who knows what they were capable of thinking.

Accelerated? I'm betting they meant "Progressive".

[MIA_eccl1212]

Some architects and engineers simply must NOT be allowed to build the “wall” to our south... in the Western USA...

liberals: building things that are unsustainable to support from the beginning of time.

[Ban Draoi Marbh Draoi]

This is what happens when people no longer accept objective truth — in anything.

[Damsforgood]

So maybe it’s self supporting without cable stays - barely. Figg (and Muller) were known for complex designs that were tough to build. (I think there was a precast segment accident during the Sunshine Skyway build by Paschen in the mid 1980’s).
The temporary supports were pulled and the top of the new bridge goes in compression. When cable stays are installed and tightened later the top of the concrete canopy is stretched out again - all is good.

So somebody notices the “loose” tendons on the top of the canopy before cable stays are installed and decides they need to be stressed more - not “Stress tested”. The canopy gets overstressed, buckles and the whole thing comes down. Note a crane and manlift at the point of failure in the blurry video.

Failure of the “Responsible Engineer in Charge” regardless.

[6ppc]

But this bridge used the “innovative Accelerated Bridge Construction” method developed at the university. Who knows what they were capable of thinking.

Surely the department head was a licensed PE! Saw an article where he had a lot to do with the design. See a lot of messy lawsuits coming.