I guess people on the news are complaining and asking how this devastation could happen in a highly seismic area where the buildings are supposed to be earthquake resistant. These people do not seem to get it that it takes money to fix the vulnerable buildings, money the owners may not have and do not want to spend.
I guess some people do not listen to structural engineers either.
They just listen to the money.
Unreinforced masonry is a problem there, here, and everywhere earthquakes happen.
With older towns, and in this case perhaps, an historical village with centuries old masonry, this is the result I guess.
I seems at first glance to me that it would be impossible to upgrade these old villages to current seismic resistance without spending enormous amounts of money and essentially destroying the aesthetics/value of these old structures.
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What would happen if one put, say, 4" 3/8"T steel angle on all four vertical corners and all four top edges tying them together. Would these structures keep their integrity enough to not generally kill all their residents or would they still spall inward and ultimately convert to piles anyway?
These walls more than likely failed from seismic forces normal to their large face (their weakest plane), not in line with the wall, and the angles you propose, or any edge members for that matter, would do little to no good to resist that scenario.
The entire wall would literally have to be stitched together via some structural means that would, in all likelihood, ruin any architecture of the area.
Earthquakes in the 5.5 to 6.5 magnitude range are a relatively common occurrence along the Appenines. Assisi caught it in 1997 and again in 2009.
With death tolls in the low hundreds each time, a frequency of occurrence measured in years rather than decades, a history that goes back forever and no clear way to blame anybody for the quakes themselves, we're right in the middle of the territory where people resign themselves to the risk and just get on with life.
Outsiders may have a different view: I was taking photos from the top of a quite squinty tower in the the middle of Bologna a week before the quake happened and as a tourist from the UK the thought definitely crossed my mind that if the ground started shaking while we were up there, it was going to be an exciting ride.
I think the distance from the epicentre is the bit that makes the difference here - they have relatively large numbers of relatively small, relatively shallow quakes, meaning that any particular building can go a long time before it sees a severe test.
Some of the churches I was admiring a couple of weeks back are bold structures and a long way off the straight and level, yet date back to the 12th Century (and are still there this week).
I heard that the buildings imploded implying that the roof strunture went up, displacing the walls to the inside of the structure. When the roof came back down, the walls collapsed to the inside of the structure.
The through the wall rosettes you saw in Frisco were placed at the floor and roof diaphragm levels to keep the floor and roof joists from separating from the brick walls.
The walls still see forces normal to them and have to span vertically between the floors and roof in a seismic event.