Apartment Building Collapsed Near Miami

Elefantman

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Those photographs of the concrete are nasty. From experience, COAs are notoriously stingy about spending money. I'm sure they didn't like this report at all...
I remember reading somewhere that each condo owner would have to put up 100K for the needed repairs. I would imagine most couldn't manage that.
 

dayhiker

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🤷🏼‍♂️Highly unlikely??
I agree that it’s highly unlikely but this isn’t a completely true statement either
“On that basis, a building designed to South Florida standards should survive your average earthquake in California,” he said.
I’ve designed things in south Florida and around Memphis/New Madrid and there some significant differences.
 

dayhiker

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I agree that it’s highly unlikely but this isn’t a completely true statement either
I’ve designed things in south Florida and around Memphis/New Madrid and there some significant differences.
I should have added that it depends on what is meant by your average California earthquake. I would expect a building designed for South Florida winds to do just fine in a 3.9 mag that's 100 miles away though.

Earthquake loads are a function of the mass of the building. The heavier the building, the higher the load you have to design for. Also, since a building is like a pendulum, the design forces are top loaded, meaning that you don't have the same force pushing on every floor. You have a higher percentage of the forces at the upper floors and then the load drops. Said another way, if you have a lateral load of say 100k (100,000#) on a building, the amount of overturning due to that 100k which be much higher if it comes from seismic than it would be if it came from wind. The other issue is that it's the intense cycle reversion that is so damaging in earthquakes. You detail a building different in seismic because the code requirements are there to provide ductility to survive the cyclic loading. By detail the building, I meant how the reinforcing is proportioned, where it occurs, lots of small details that matter. Column splice rebar, for example, occurs at the floor level ideally. In seismic zones you have to do the column splices at mid height of the columns instead. I believe I'm remembering that correctly. It's been a few years since I did one of those.
 
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TIDE-HSV

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I remember reading somewhere that each condo owner would have to put up 100K for the needed repairs. I would imagine most couldn't manage that.
I read a figure not quite that high, around $83K, IIRC, but still a significant financial strain, particularly for those on fixed incomes...
 
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TexasBama

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I agree that it’s highly unlikely but this isn’t a completely true statement either
I’ve designed things in south Florida and around Memphis/New Madrid and there some significant differences.
Unless the blast was set off on rock, and the building was built on rock, I couldnt imagine any effect. 100 mile of water will dampen a big blast.
 

dayhiker

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Unless the blast was set off on rock, and the building was built on rock, I couldnt imagine any effect. 100 mile of water will dampen a big blast.
It's the opposite. Soft soils amplify the effects. You modify the design forces based on the soil type. The softer the soils, the higher the design forces.
 

TIDE-HSV

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It's the opposite. Soft soils amplify the effects. You modify the design forces based on the soil type. The softer the soils, the higher the design forces.
As soon as you wrote that, I thought of the filled areas of San Francisco which liquefied in both the 1906 and 1989 quakes...
 

TexasBama

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It's the opposite. Soft soils amplify the effects. You modify the design forces based on the soil type. The softer the soils, the higher the design forces.
I guess I was thinking more on velocity. Although if they set that blast st or near the ocean surface I can’t see how appreciable force would make it to the shore, as the water’s pretty deep there.
Doing some digging, it appears that wave propagation from an earthquake is fairly complicated
 

TIDE-HSV

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TIDE-HSV

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Accounts are starting to come out of infighting on the COA board, with resignations, etc. This is probably because the bill for deferred maintenance had risen so high...
 

dayhiker

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Accounts are starting to come out of infighting on the COA board, with resignations, etc. This is probably because the bill for deferred maintenance had risen so high...
I looked at a building once that partially collapsed 2x. Both times it was because they didn't clean the goose poop out of the roof drains and they didn't have overflow scuppers.

Maintenance? Nah, we don't need it. It won't REALLY fail. Those engineers are just overly cautious.
 
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