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Total Building Collapse from a Single Column Failure

JSanderO said:
The information about steel columns for Euler buckling is a slender column can not exceed SR 150 the ratio of the radius of gyration - the x or y axis of the column plan to the length.

the numbers are the x and y axis dimension X 150 to find the upper limit (SR) for each axis of the column.
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Radius of gyration is the square root of the moment of inertia over the area of the shape. It's not a plan dimension. Once the slenderness ratio exceeds that, it enters elastic (aka Euler) compressive behavior. I frequently use gravity columns with slenderness ratios that exceed this ratio.

There is no dispute that unbraced columns bear less axial load than braced. The assertion is that so much of the bracing was removed that the column lost capacity and buckled.

I don't see that failure mode .. or even as you assert 70 something feet were unbraced and the column buckled. Your numbers don't sell me. Try a different approach...
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Probably because you don't understand the math or concepts involved...

Content in the link is not viewable for non ASCE members.
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AISC, not ASCE. Please pay attention. And yes the content is available for everyone. I clicked on the "2010 Specification for Structural Steel Buildings (ANSI/AISC 360-10), Second Printing" link and lo, the PDF appeared.
 
Newtons Bit said:
Radius of gyration is the square root of the moment of inertia over the area of the shape. It's not a plan dimension. Once the slenderness ratio exceeds that, it enters elastic (aka Euler) compressive behavior. I frequently use gravity columns with slenderness ratios that exceed this ratio.



Probably because you don't understand the math or concepts involved...



AISC, not ASCE. Please pay attention. And yes the content is available for everyone. I clicked on the "2010 Specification for Structural Steel Buildings (ANSI/AISC 360-10), Second Printing" link and lo, the PDF appeared.
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I am not going to argue with you. I am not an engineer. But let's move on and explain a single girder walk off caused the column line to buckle... and if it did... what is your explanation for why NIST failed to produce and the of segments of column 79 to show this buckling?
 
JSanderO:

I don't get it. Why do you make statements like this:

But let's move on and explain a single girder walk off caused the column line to buckle... and if it did... what is your explanation for why NIST failed to produce and the of segments of column 79 to show this buckling?
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This is a strawman. You post like a "truther" sometimes.

Newtons bit is an engineer (a point that is obvious). Why waver back and forth from truth and "truther"?

:confused:
 
JSanderO said:
I am not going to argue with you. I am not an engineer. But let's move on and explain a single girder walk off caused the column line to buckle... and if it did... what is your explanation for why NIST failed to produce and the of segments of column 79 to show this buckling?
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Right here, right now, is your opportunity to rise above the Dunning-Krueger Syndrome that is affecting you.

NB is explaining things to you, things that you get wrong or have misunderstood. He is better at this than you are. Just accept that. Your basic engineering classes that you presumably took as preparation for a long career as an architect, nor your field experience, have given you as clear an understanding of these engineering concepts that you believe they have.

Now man up and listen. Admit where you're wrong. Hell, even the twofer trolls like david watts, etc have on occasion admitted where they are wrong. Are you seriously LESS open to education than they are? You ain't all that, so it's time to get over yourself.
 
Seymour Butz said:
Right here, right now, is your opportunity to rise above the Dunning-Krueger Syndrome that is affecting you.

NB is explaining things to you, things that you get wrong or have misunderstood. He is better at this than you are. Just accept that. Your basic engineering classes that you presumably took as preparation for a long career as an architect, nor your field experience, have given you as clear an understanding of these engineering concepts that you believe they have.

Now man up and listen. Admit where you're wrong. Hell, even the twofer trolls like david watts, etc have on occasion admitted where they are wrong. Are you seriously LESS open to education than they are? You ain't all that, so it's time to get over yourself.
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I haven't a glue what syndrome you are referring to. But I see a lot of sycophancy and insultsand people who refused to think for themselves.

I admitted that I can't argue with Bit on engineering. I still don't accept that the girder walk off of fire on one floor caused the column to buckle or "fail" to use Ozzie's term. The column did "fail" in that it was not able to support the columns above and the EPH... but as far as I am concerned we don't know WHERE that was and a single girder walk off on floor 13 is not going to lead to Euler buckling... or perhaps BIT can explain that.
 
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JSanderO said:
I haven't a glue what syndrome you are referring to. But I see a lot of sycophancy and insultsand people who refused to think for themselves.

I admitted that I can't argue with Bit on engineering. I still don't accept that the girder walk off of fire on one floor caused the column to buckle or "fail" to use Ozzie's term. The column did "fail" in that it was not able to support the columns above and the EPH... but as far as I am concerned we don't know WHERE that was and a single girder walk off on floor 13 is not going to lead to Euler buckling... or perhaps BIT can explain that.
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Yes, you have opinions, don't understand what probable is, and call us pixels. Got it. You might want to work things out first, or you might do something like joining Gage again. It is like you still think 911 was an inside job, or something. And you are obsessed with NIST, but doing better, a lot less "NIST failed" stuff I think. Don't use NIST, use evidence, or plans, or anything. Wait, is this a with or against us kind of opinion thingy?

Where is your engineering stink?
 
JSanderO said:
Yep and others too who accept it. Where's the steel? Why didn't they show one bit of evidence?
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See the NIST report for the explana... oh... right. You believe that they faked their analysis, yet you won't show one shred of evidence proving that.
 
JSanderO said:
Yep and others too who accept it. Where's the steel? Why didn't they show one bit of evidence?
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And this is Monday morning quarterbacking.

They wouldn't have known to save col 79 until AFTER the study. Therefore, in order to meet your wishes, they would of had to save EVERYTHING.

Again, that's lidicrous
 
Seymour Butz said:
And this is Monday morning quarterbacking.

They wouldn't have known to save col 79 until AFTER the study. Therefore, in order to meet your wishes, they would of had to save EVERYTHING.

Again, that's lidicrous
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excuse me Mr Butz... You have a major building collapse. You have thousand of top engineers and scientists willing to help. You had FEMA who put out a model along with ideas from the ASCE within months if not weeks of the collapses and they were in charge of explaining it.... and by the way all the steel or a fair amount was sent to Fresh Kills for some form of inventory. Lots ended up in JFK and all over the USA including at a NIST facility... why did they save THOSE bits of steel instread of the steel from under the EPH for example... as everyone saw this was the first thing to collapse. Seems a logical place to start.

How bout asking Cantor the building's engineer... He had some ideas (which were ignored)...

Let's just make up a model! Whoopieeeeeeeeeeeeeeeeeee
 
Robrob said:
Out of curiosity, did they save all the steel from Pearl Harbor?
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the cause of sinking was not an issue... ships sink when they are holed...

towers don't totally collapse when they are on fire... usually... capice?

unusual circumstances call for unusual care in investigation.
 
Newtons Bit said:
See the NIST report for the explana... oh... right. You believe that they faked their analysis, yet you won't show one shred of evidence proving that.
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I have no intention of proving anything.

I have simply asked for the mechanism and sequence explaining how a girder walk off turns into a total building collapse...

NIST didn't explain it and you won't either.
 
JSanderO said:
the cause of sinking was not an issue... ships sink when they are holed...
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Wait for it...

towers don't totally collapse when they are on fire... usually... capice?
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Please provide an example of a building constructed as the WTC were constructed which were struck by jet aircraft then burned for an hour plus which didn't collapse?

unusual circumstances call for unusual care in investigation.
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The "circumstances" were not the least bit "unusual" and were known almost in their entirety within a week of 911. I find it odd you would not know that.
 
JSanderO said:
I haven't a glue what syndrome you are referring to.
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There's this thing called Google.....

But basically, you're out of your depth here. You don't know enough about the engineering to even have an opinion. But you think you ARE proficient at it.

But I see a lot of sycophancy and insultsand people who refused to think for themselves.
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Sometimes, folks shouldnt come to their own conclusions. This is a time when you should just stfu and listen.

I admitted that I can't argue with Bit on engineering.
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If you can't, then that makes the probability that your arguements are correct practically nil. Do you realize that?

I still don't accept that the girder walk off of fire on one floor caused the column to buckle or "fail" to use Ozzie's term.
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Straw man

but as far as I am concerned
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You don't have the chops to form a valid conclusion.

we don't know WHERE that was
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Somewhere along the 8 floor span from 13-5. Exactly where doesn't matter.

and a single girder walk off on floor 13 is not going to lead to Euler buckling...
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Agreed. But this is a straw man for NIST doesn't claim this either

or perhaps BIT can explain that.
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He did
 
JSanderO said:
the cause of sinking was not an issue... ships sink when they are holed...

towers don't totally collapse when they are on fire... usually... capice?

unusual circumstances call for unusual care in investigation.
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Fire collapse; Oops, yes they do, you must of missed 911.

What? Gee whiz, it was unusual, but the idiots used aircraft they stole by faking a hijacking, which automatically gets you an hour or two of special handing like you are an emergency! And no interception is automatic.
Unusual? When an aircraft with 66,000 pounds of jet fuel, 10,000 gallons of burning jet fuel sets fires on multiple floors in seconds, you think fire is not a factor which can explain the collapse? 10,000 gallons the most fuel used to set a high-rise on fire in history?

I have yet to see a building survive a fire not fought - but go ahead show me.

The fact 911 was so unusual, but the methods used by the murderers made it easy to pick them out from the passengers, and then the big impacts made it easy to figure out the physics, and the fires.

Fires not fought? lol

There was fire, and there were real reasons the WTC collapsed due to 19 terrorists, not your inside job stuff you first suspected.

Why make up silly opinions about NIST and 911? Why are you obsessed with NIST?
12 years, you could have earned a PhD in structural engineering instead of have silly opinions based on what you think should happen in fires, and forgetting they were no fought.

If I was in your spot, I would keep the opinions to myself, earn an engineering degree, at least a masters and try for a redo.
How long did you believe the inside job stuff?
 
JSanderO said:
I have no intention of proving anything.

I have simply asked for the mechanism and sequence explaining how a girder walk off turns into a total building collapse...

NIST didn't explain it and you won't either.
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Don't expect any more meaningful replies from me if continue to arbitrarily declare explanations as "faked". Why should I waste my time?
 
Newtons Bit said:
Don't expect any more meaningful replies from me if continue to arbitrarily declare explanations as "faked". Why should I waste my time?
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Good answer... or evasion...

NIST created a model... they said so... made up the inputs... a fake... may be the wrong world... but it's not far off...

THEY MADE IT UP...

Fine...

So why can't they say how it worked... or you or as I noted... why didn't they show one piece of steel to support their model?
 
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