40-ton timber arches collapse in Hickory, NC 35

[bugbus]

https://www.wsoctv.com/news/local/n...king-busy-highway/N7L3RUTIKJE23LLTGYBXGJPM5U/

Before:

After:

 

[Tomfh]

The 5 “pins” would have provided some rotational resistance, but not enough to keep it standing.

 

[dik]

It's all dependent on how secure the bottom supports are. If they can provide a rigid base, then it's a three pinner... if not, it's a 'turkeyshoot'. the movement appeared to be limited to the top three pins, but my failing eyes cannot tell for sure.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[hokie66]

It was only a 5 pin arch for forces parallel to the axis. For lateral force (wind), it was unstable above the wishbones once the rotational resistance of the connections was overcome. The cables may have been provided in recognition of that instability, but did not do the job.

 

[dik]

Concur... even the cables may have had a 'snap through' point where they became useless... and see how quickly it becomes unstable with movement:

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[spsalso]

The turnbuckles used a huge amount of takeup because the structure provided too little resistance. There were no loose joints that needed slop removed. The damn thing bent. This doesn't HAVE to be bad--lots of things bend by design.

I don't think this one bent by design. If it DID, I surely look forward to the explanation.

spsalso

 

[Tomfh]

No doubt those knuckles were imagined as continuous parts of the arch, and yet ended up bending a lot. Bending down due to the tensioning of the rods, and then bending the other way when it fell over.

 

[dik]

Bending makes it less stable, and once it reaches the 'snap through' point, the cables become useless, no matter how well they are anchored.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[1973Hokie]

The latest news from Hickory, NC regarding arches:

https://hickoryrecord.com/news/loca...cle_3e950822-967d-11ec-91e5-af255951d15c.html

 

[spsalso]

The mayor says it was a "catastrophic event".

As I watch various news sources and video feeds today, I do think the mayor just might be overstating his case.

Maybe they need a new mayor, who has a sense of proportion. Or just sense.

Meanwhile, Western Wood Products still has nothing to say about this on their website. Perhaps they feel there's no reason to rush.


spsalso

 

[Alistair_Heaton]

small town mayor,

WWP is sensible say nothing until the facts are known. Even if they know already its not their fault.

 

[Tomfh]

I’m sure they’re busy working out all the ways it’s not.

 

[LittleInch]

It was a potentially catastrophic event for sure - if anyone was actually crossing the bridges or if a train had been running and it fell the other way.

Difficult to see how a structure which is less than a year old and fell down in nothing more than a stiff breeze isn't a design issue. They were supervising during construction so can't back away from that responsibility.

The joint between the A frames / wishbones and the rest of the arch would seem to be the key area of interest and likely failure location.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[spsalso]

"potentially catastrophic"

Yes. But it wasn't. It fell down, went boom.


spslso

 

[Denial]

Perhaps we need a special forum for word games, but my Oxford dictionary defines "catastrophe" as:[ ] Sudden or widespread or noteworthy disaster;[ ] event subverting system of things;[ ] disastrous end, ruin.[ ] It then elsewhere defines "disaster" as:[ ] Sudden or great misfortune;[ ] calamity;[ ] complete failure.[ ] [My emphasis]

So, definitely catastrophic.[ ] And potentially fatal.

 

[Red Corona]

Complete and sudden failure is what "catastrophic" means in engineering yeah. The forum isn't called catastrophes, anyway, and this is definitely an "engineering failure". Can I have membership of the word game forum?

 

[spsalso]

It surely was a "complete failure". Beyond the thing falling down and needing to be cleaned up eventually, it appears most of the catastrophe was the damaged bridge railings.

I wonder what the mayor would have called it if several someones were killed in the process, or one or two bridges taken out. Would "mega" or "super jumbo" have been appended?


spsalso

 

[IRstuff]

We're nitpicking someone's words for amusement, but if my house were to burn down it would be catastrophic to me, irrespective of any damage to anyone else's property.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[spsalso]

Re: your house burning down.

If the town burned down, that would be a catastrophic event.

This seems more like having the decorative fountain in your front yard fall over and break, after you paid good money for it.

However. I have noted that I am unimpressed with the mayor's choice of terms. Others may not have that reaction.


spsalso

 

[dik]

Depending on the town, it might not be.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Electronbelt]

Hickory Council Comments (wbtv.com)

In a city council meeting, the City of Hickory says they will not be conducting an independent investigation into the collapse of two arches over the City Walk pedestrian bridge over Highway 27 on Feb. 18.

Officials say the city never accepted ownership of the arches. Officials say the project was technically incomplete until the DOT signs off and the city formally takes ownership.
....
The North Carolina Department of Transportation owns the bridge, according to Hickory City Council. Therefore, the city does not have the authority to remove the arches, so other parties will have to remove them.
....
The city says multiple groups are investigating and developing reports on why this happened. The city is not one of those groups investigating. Officials say the insurance company advised the city not to get involved in the investigation.