Can 15 floors crush one floor?

[Tony Szamboti]

As I'm sure you know by now, my WTC7 trace data is particularly high quality, and I've just shown you a graph of the velocity.

Where is the jolt you are referring to ?


David's data is not great Tony.

A bit like the missing jolt data.

Are you going to make me drag out "your" "missing jolt" data (which you didn't even generate) and critique in a similar way to that applied to the NIST trace data ?

(You've heard it all before of course, but never bothered to address any of it...years later...with data I've made freely available)


What difference did I say it made ?

I suggest it dwarfs the calculation you performed earlier about column alignment with a 1 degree tilt.

10cm > 1cm ?


Why ? I showed small jolts that were in the data, because they were there.

What exactly is silly about that ?

Certainly less "silly" than using low fidelity, low sample rate data taken from low quality video which has been processed incorrectly...to make conclusions, which, when questioned by supply of superior data...you ignore.

Perhaps you'd like to actually answer the rather relevent questions you've ignored...

1) What impacted what ? And when...or over what time period did the "many" "sub-jolts" occur ?

2) Whatever you think did impact...via what path and materials did that "jolt" have to pass through to reach the NW corner ?

3) What does 1 degree of tilt actually DO to your calculation ?

You haven't shown anything. You are an anonymous poster claiming he has found things nobody else has and applying back handed logic that doesn't work.

I have answered the questions you are asking many times in the past. Go find them.

 

[femr2]

You haven't shown anything. You are an anonymous poster claiming he has found things nobody else has and applying back handed logic that doesn't work.

What on Earth are you talking about Tony ? You sound exactly like Chris7, which is particularly sad.

I have answered the questions you are asking many times in the past.

No, you haven't, and you know well that I have no problem trawling back through to confirm such.

I've been asking you this same question for two years.

Much simpler to just answer it.

What impacted what ?

 

[ozeco41]

..I've been asking you this same question for two years.

Much simpler to just answer it.

What impacted what ?

That is the key point for the ROOSD collapse progression - once it is established and as it continues - "progresses" if I risk using that word

..and is as much as Tony has already acknowledged.

What impacted what? is certainly nothing to do with any abstract modelling. It only applies to what really happened.

And "What impacted what?" is also the key point for the transition from "initial downwards movement" into ROOSD. Where Tony has issued his challenge - just few posts back in this thread - let's see if he can explain it for us.

Because I certainly can and I am sure you can also.

I'd better stop asking hard questions and go back to nit-picking details like a good debunker.

 

[tsig]

First, transfer of momentum requires a deceleration on the part that is transferring it. There is no deceleration in the North Tower's fall measurement.

The deceleration required for a gravity driven collapse would have been at least about 3g's.

Finally, the difference in length with the 207 foot wide face tower section with a 1 degree tilt would have been (207) - (207 x cos of 1 degree) = 0.0315' = 0.378". The initiation occurred in the North Tower at the 98th floor and the perimeter columns were 14" square with 7.5 mm webs and flanges at the 97th floor with spandrel beams behind them. The core columns were larger in most cases and would have had less misalignment since they were closer to the north face fulcrum. There clearly would not have been any misalignment significant enough to cause them to miss each other. The lateral inertia of the upper section would keep them aligned. So the only way it could happen is with enough tilt, which can be shown not to be there. Those who say the columns would have been misaligned have nothing technical to back what they say. They are actually talking out of something other than their mouth.

You think all the columns in the top part would have landed squarely on the columns in the bottom?

 

[Justin39640]

The upper 33 stories of WTC 7 had a significant deceleration after a 16 story fall and you have been shown that and I have explained the stiffness issue to you before.

Um... wouldn't that be the point where the majority of the upper 33 floors were hitting the ground? I don't think the stiffness of the upper block should concern you... more the stiffness of what it's landing on (like the ground, for example).

 

[Justin39640]

You think all the columns in the top part would have landed squarely on the columns in the bottom?

Of course he does. And he has all his calculations on the backs of napkins to prove it! lol

 

[ozeco41]

BUT, napkins ot not, he starts from the scenario that the "top block" was falling.

#...and, at that stage all the columns had failed, by ruddy definition. The top block was falling. So everyone stop and think till that sinks in then call it "Point 1" got it? If so than go to the next step: If not go back to #

THEN

Point 2 - all the column ends were already missing each other OR were set up so they would miss (OR would be near instantly re-buckled if they tried to land back in apposition. - this one to allow for a remote possibility which could only apply to very few columns if any AND would self eliminate.)

And understanding why those two points are simple facts demolishes all the misinterpretations including the "circular self sustaining 'logic' of the jolt that wasn't missing because it never was."

 

[Travis]

I fail to see why column alignment matters at all.

I speculate that: once a building portion of 15 floors accelerates at one g over a distance of 12-15 feet it will fail whatever portion of the below structure it impacts regardless of alignment.

 

[Tony Szamboti]

I speculate that: once a building portion of 15 floors accelerates at one g over a distance of 12-15 feet it will fail whatever portion of the below structure it impacts regardless of alignment.

That isn't an automatic. It depends on the strength of the structure below.

If you are following this issue much at all you would know there have been failed controlled demolitions. Some of these failures can be seen on the Internet. Why did they fail?

 

[ozeco41]

I fail to see why column alignment matters at all.

I speculate that: once a building portion of 15 floors accelerates at one g over a distance of 12-15 feet it will fail whatever portion of the below structure it impacts regardless of alignment.

But that is why I asked you if you were discussing WTC 9/11 - your scenario is not WTC 9/11. nor does it matter what really happened if you want to address some phantom building which is not WTC on 9/11. Another reason I asked you to be clear in the posts you have ignored. you are not dealing with either the real what happened collapse of 9/11 at WTC OR the abstract modelling approximations of the same.

A few members here are discussing genuine approaches to the main two ways of dealing with what happened at WTC on 9/11. your scenario glosses over the reality so there is no point any of us offering reasoned discussion. Despite that I'm sure you will get comments..

A few main points:
1) where did you create the 1G over one story? It didn't happen in the real collapse.
2) where did you acquire the free space for one storey fall? That didn't happen in the real collapse
3) How does your "15 storey" manage to impact on an assumed single portion of what is below? that is not possible - in either direction. No way will the 15 storey bit land on a single point. No way will a single point contact allow the full weight of those 15 stories to impact with full loading (the frame would be too elastic and would dampen much of the impact.)
4) what do you even mean by alignment when you haven't defined what is hitting what? most of us in this discussion know what we have in mind and we also know the alternate concepts even though we may not agree fully with them. your scenario is not even defined in any meaningful way.

 

[Tony Szamboti]

I fail to see why column alignment matters at all.

I speculate that: once a building portion of 15 floors accelerates at one g over a distance of 12-15 feet it will fail whatever portion of the below structure it impacts regardless of alignment.

If you are speaking of the North Tower, with the 15 floors, and have it accelerating at one g through its first story of fall you need to update yourself on the specifics.

The initiation occurred on the 98th floor, so it was 12 floors. It accelerated at about 5 m/s through that first story and at about 6.2 m/s^2 thereafter. So it wasn't a one g fall.

By the way, a one g fall is impossible in a natural collapse initiation due to buckling columns, as buckling columns have a significant minimum resistance.

 

[Justin39640]

By the way, a one g fall is impossible in a natural collapse initiation due to buckling columns, as buckling columns have a significant minimum resistance.

That's a lie...

 

[Travis]

Who cares what initiated this here. Maybe a wizard willed the columns out of existence.

What I'm speculating about is that once a 12-15 floor chunk of commercial office building starts moving under the acceleration of gravity over just a one floor vertical drop no structure beneath it will arrest it. Not one floor. Not 92 floors.

Maybe I'm way off base with this. If so I'd appreciate correction.

 

[tsig]

If you are speaking of the North Tower, with the 15 floors, and have it accelerating at one g through its first story of fall you need to update yourself on the specifics.

The initiation occurred on the 98th floor, so it was 12 floors. It accelerated at about 5 m/s through that first story and at about 6.2 m/s^2 thereafter. So it wasn't a one g fall.

By the way, a one g fall is impossible in a natural collapse initiation due to buckling columns, as buckling columns have a significant minimum resistance.

Cite?

 

[Oystein]

It is incredible that you think the column flange and web areas have to hit exactly square area to area to cause a deceleration ...

It is incredible that you think the column flange and web areas DON'T have to hit exactly square area to area to cause a deceleration of 3 g's, which is your claim.

If the area is reduced by almost 99%, as a lateral shift inwards by 1cm would cause, then the deceleration is reduced by a similar (not same, but corresponding) margin, and your "3 g's" become something like "<<0.3g's" - which would be perfectly in line with observations.

...and then to top it off you have the nerve to question me. This is precisely why people like you don't get answered. Go play in a sandbox somewhere.

Sorry I made you answer a question and thereby display how out of alignment with reality you are.


ETA:

I have cautioned Oystein on the risk of joining you down in the detail - whilst letting you get away with wrong context or assumptions wrong. But you should thank him for playing at that level. He's a nice co-operative fellow.
...

Thanks for the urrrr... never mind
BUT my fun thing here is not to show that Tony is wrong vis-a-vis reality, but that he gets things bizarrely wrong even within his own false premises!

 

[thedopefishlives]

Who cares what initiated this here. Maybe a wizard willed the columns out of existence.

What I'm speculating about is that once a 12-15 floor chunk of commercial office building starts moving under the acceleration of gravity over just a one floor vertical drop no structure beneath it will arrest it. Not one floor. Not 92 floors.

Maybe I'm way off base with this. If so I'd appreciate correction.

Dave Thomas has done some pretty nice math showing that the kinetic energy of the upper block would have been more than enough to cause the columns to fail had they hit square, as Tony S. seems to think they did. Something like an impact equivalent to 30 times the mass of the entire building, if I recall correctly. Resident Twoofer ergo believes that this would not be sufficient, but I think any rational person could see that this is well past the design limits even of the column structure. In any event, it is irrelevant - once the collapse got underway, it was clearly inevitable from the kinetic energy alone, whether the columns impacted each other or missed and caused the force to land on the floor pans.

 

[Oystein]

... There clearly would not have been any misalignment significant enough to cause them to miss each other. The lateral inertia of the upper section would keep them aligned. So the only way it could happen is with enough tilt, which can be shown not to be there. ...

I missed this the first time around:

Tony seems to be arguing that in a natural, unassisted collapse, there is no force that could impart a significant lateral momentum on the center of mass of the collapsing structure.

It follows, from Tony's argument, that the only direction a natural collapse can progress is vertically down - which will land it its footprint.

Thank's to Tony for disproving the validity of one of AE911T's main arguments

 

[RedIbis]

Who cares what initiated this here. Maybe a wizard willed the columns out of existence.

What I'm speculating about is that once a 12-15 floor chunk of commercial office building starts moving under the acceleration of gravity over just a one floor vertical drop no structure beneath it will arrest it. Not one floor. Not 92 floors.

Maybe I'm way off base with this. If so I'd appreciate correction.

Correct me if I'm wrong, but aren't you just insinuating pancake collapse with this?

 

[NoahFence]

It is incredible that you think the column flange and web areas have to hit exactly square area to area to cause a deceleration and then to top it off you have the nerve to question me. This is precisely why people like you don't get answered. Go play in a sandbox somewhere.

He's certainly not the only non engineer who knows you're full of it.

Your arguments fail on every level, and when compared to actual engineers arguments?
That's when the facepalms come rapid fire.

 

[Oystein]

...
By the way, a one g fall is impossible in a natural collapse initiation due to buckling columns,

This seems to imply that something (what?) fell onto columns, and that would be a partial answer to femr2's question "What impacted what ?".

So is this your claim? That, in the actual WTC collapses, "something (or columns?) impacted columns"?
femr2 told you that he can show that columns were NOT impacted. Can you show the contrary, that they were? Do you deny that femr2 can show they were not?

as buckling columns have a significant minimum resistance.

This raises an obvious question: How long (over what distance or time) do buckling columns have a significant minimum resistance, and at what point, if ever, do they turn into buckled columns, have no significant minimum resistance?
You may answer this by either pointing towards applicable evidence from the actual WTC collapses (showing columns in the process of buckling), or by discussing from engineering principles, using well derived, documented, tabulated data and knowledge about the behaviour of columns experiencing impact and platic deformation.

(My amateur intuition tells me that a steel column may offer full, or even more than full, resistance, through a distance of a few % of its length; then resistance will decrease dramatically, and become effectively 0 a few % later. My intuition tells me further that this is mere theory, because columns will more typically buckle at their joints. And a couple of years reading this and other forums and appreciating the actual evidence suggest to me that column buckling played no great role during collapse progression, as it was mostly floor-to-column connections that lead the way. Let's see what your "professional" (I understand that you are not quite in the right profession, but hey...) intuition tells you. This shall be more fun.)