Thread by @AskGregory

#SurfsideBuildingCollapse
#MiamiBuildingCollapse
Take another look here @EngineeringWon1, three days ago I was speculating that these very regular sets of parallel lines look like a series of precast slab panels that had moved relative to each other.
Now, removing the bias I see:

https://twitter.com/MiamiDadeFire/status/1408177688515428353

looking again I and following the lines towards the camera you will see at least one column, implying one of a line of columns supporting the slab above. The dark ripped out lines are perpendicular to the line of columns visualised above. Notice how the lines end near the column:

Let's say the ripped out lines are in the longitudinal direction and the line of columns in the transverse direction. Now notice how the ripped out lines end near the transverse zone. This appears to be because reinforcing or post-tension tendons lift up to the top of the slab...

.. to the top of the slab to accommodate negative bending moments at the top of the slab along the transverse line. This reinforcing or these tendons seem to have broken off at regular positions.
It is odd however that no reinforcing is dangling out where the rip lines end..

if these lines are indeed the paths of post-tension tendons one can speculate that this design was followed all the way to the top of the building. If this is true the jacking force would have been applied to the tendons all along the periphery of the building on facade side edge

@threadreaderapp
Unroll please