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275 points testrun | 8 comments | | HN request time: 1.225s | source | bottom
1. lordnacho ◴[] No.43503986[source]
I was wondering about the collapsed building in Thailand that was under construction.

Do civil engineers take precautions for under-construction buildings? Do they minimize the risk somehow? I'm guessing there's inevitably a window during which an earthquake would be catastrophic, even if the end product is earthquake resistant.

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2. jeffbee ◴[] No.43507325[source]
It doesn't seem like the state of being under construction would have been the problem. It's a reinforced, poured-in-place concrete building. It should be as strong in that state as it would ever have been. Suggests a design error.
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3. lucianbr ◴[] No.43507570[source]
It's not inevitable by any means. There's definitely a way to build buildings so that at any point they are as resistant to earthquakes as they will be at the end.

Actually I think it would take special effort to make it so it's vulnerable during construction but safe at the end.

For example, do you think the foundation of the building is somehow weaker during construction but gets stronger at the end? How could that possibly work?

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4. catherd ◴[] No.43508077[source]
Concrete foundations get stronger as the concrete cures (around a month).

Framing is much more resistant to collapse once you put sheathing on it, a roof, etc. Before that it is easier to fall over.

A half built wood frame wall only supported at one end is like a wet noodle if you don't put in some temporary braces.

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5. treis ◴[] No.43508159[source]
There's stuff like tuned mass dampers that reduce sway. The top floors would not necessarily be completely attached either. Can see them falling and taking out the lower levels with them.
6. ◴[] No.43511786[source]
7. scarab92 ◴[] No.43511853{3}[source]
The concrete is supported by formwork and props until it cures, which appear to have been removed on all floors, suggesting that the concrete structure was now complete and the building is about as strong as it ever will be.

The collapse must have been due to a design or construction mistake.

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8. defrost ◴[] No.43511891{4}[source]
There are a number of post concrete cured enhancements to buildings that improve earthquake resistance that may not yet have been added (if planned) .. antisway damping, additional bracing and or bridge like cabling, etc.