Bad design or poor workmanship or both.. Somebody didn’t know how to build this thing correctly.
There’s an overlying logic to the whole thing, and that is “Accelerated Bridge Construction”. This bridge was designed as a “cable stayed” bridge, and the blueprints and even animated images of this conception have been widely disseminated.
This design includes a tower with “stays” or “cables” or in this case what have been called “pipes”, providing slanting support from a single tower to hold up a a bridge deck which has been designed for this concept.
Enter “ABC” or “Accelerated Bridge Construction”. This stands in conflict with the cable stayed design, which requires a step by step addition of the bridge deck as the stays are added. Very meticulous and time consuming.
So, FIGG decides that this is all unnecessary, and the bridge deck can support itself. So powerful is this suggestion, that it is routinely reported that the bridge is of a “truss design” and that the mast, with its cable stays, are COSMETIC, which I find shocking and astounding.
So in pursuit of this chimera, the bridge deck is installed, still festooned with the “cable stay” connection points, easily visible in the news photos of the installation and subsequent wreckage.
Then, in a matter of hours, the bridge deck starts to disintegrate, as it is under tension, which it was never designed for. All this “testing” is a euphemism for a desperate attempt to save the bridge by compressing the length of the deck with preinstalled cables ( an established technique, but entirely inadequate in this case. ) So the deck sags, and the poor roof, enlisted as a top girder, gives way, as plainly evident in the widely promulgated “collapse video”, and the deck falls like so many bags of sand.
Just a scandal. No excuse. I’m waiting for the call from the networks.