Bridge construction began in 2014 while a retrofit was completed in February. ---> Youtube
The dump truck full of rocks might have been close to 100 tons, no?
What I was looking at in the first screenshot was the strapping around the concrete arch. This is obviously a retrofit given the clean arches seen on Google Maps. Was the hangar connection failing already. Was the top connection of the vertical member connected with four bolts like the lower...
There's something very wrong with that scene. The ship was moving backwards and towards the immediate shoreline with the tug in chase. Unfortunately the bridge got in the way. The ship then glanced off the shoreline just after it passed the bridge.
I suppose I can answer my own question --> As they pulled up the cut up slab sections, they disturbed the column, which was integrated with that last piece of slab which extended beneath, or stuck to the column. The column likely fractured in quick order, then slowly progressed as the...
It looks to me that the column base was destabilized by removing the slab. I'm not sure what precautions should have been taken to avoid that. I don't see the footing either.
Plenty? Oh, I missed that one.
Is it possible that by removing the slab at the base of the column, the effective six inch (or so) increase in column height tipped it over the edge? Answer: no, they couldn't cut right up against the column ... although on the thin side that cleaved off it...
So if the containment rebar is missing from that column, where else is it missing? What were they working on/with above the column to completely obliterate it. This story is much bigger than we know.
If it wasn't so serious I would laugh at the structural/facia brick differential and the idea that the facia layer can be removed with impunity. I'm not saying that was the case here but by extension, uniformed removal of any course of multi-wythed brickwork is inane.
The thin wall theory plays nicely into the out of phase oscillation theory (with the west adjoining bridge structue). A thin wall offers less resistance to lateral forces and can bow or fatigue easier, or rebar pullout can leave a much smaller percentage remaining to support the vertical load...
