yup ... indeed ..

Originally posted by -PLB-
You are in denial again. Even in this very thread there are several posts of my where I completely expose your nonsense which you completely ignored.

Where? I have addressed all of your replies mate. I have not missed anything. So far you have misunderstood most of what you post as your "evidence", and then you claim I ignored it.

Stop talking about all this evidence you have, and present it.

Perimeter columns ANOK, perimeter columns.

Oh boy.

OK then, what caused the core to collapse? The perimeter columns, and the floors, did not hold the core up. They transferred lateral loads, which are relatively small. The vertical loading of the columns was massive.

And BTW the perimeter columns were also box columns and much more massive than the lightweight trusses.

Originally posted by ANOK
Where?

Like here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...

Just to name a few of the last 3 pages.

OK then, what caused the core to collapse? The perimeter columns, and the floors, did not hold the core up. They transferred lateral loads, which are relatively small. The vertical loading of the columns was massive.

How about 15+ stories dropping on it? Whats the mystery here? You are looking for mysteries under every rock.

Originally posted by GenRadek
NIST discovered that PANCAKING was NOT the INITIATOR of collapse.

Pancake collapse IS NOT a type of collapse INITIATOR. Pancake collapse is what happens once collapse is INITIATED.

Pretty sure I've explained that to you before mate.

A building undergoes progressive collapse when a primary structural element fails [collapse initiation], resulting in the failure of adjoining structural elements, which in turn causes further structural failure, similar to a house of cards.

Progressive collapse

Originally posted by -PLB-

Originally posted by ANOK
Where?

Like here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...
and here: www.abovetopsecret.com...

Just to name a few of the last 3 pages.

OK then, what caused the core to collapse? The perimeter columns, and the floors, did not hold the core up. They transferred lateral loads, which are relatively small. The vertical loading of the columns was massive.

How about 15+ stories dropping on it? Whats the mystery here? You are looking for mysteries under every rock.

Just to say . The cores stood up to to both impacts and collapses quite well.

only failing slightly below impact zones.

Even swayed for a few seconds.

reply to post by -PLB-


Hmm I believe I did reply to those claims, first one right here...

www.abovetopsecret.com...

Took me awhile to find that, so I ain't gonna dig around to find all the other stuff I replied to. You'll also notice I made reference to your PDF in a few other replies. Wow, all the dirty tricks are coming into play now, eh?

So now who's the one actually ignoring things PLB?

reply to post by ANOK


I guess demonstrating to you in detail where you are wrong is a dirty tactic nowadays. Anok, in that PDF, what happens when the lines cross the x-axis in 5b? Just one of the questions you have been ignoring consistently.

Originally posted by -PLB-
I guess demonstrating to you in detail where you are wrong is a dirty tactic nowadays. Anok, in that PDF, what happens when the lines cross the x-axis in 5b? Just one of the questions you have been ignoring consistently.

You have yet to do that mate.

You are not understanding what the PDF is saying as I have already explained, I don't know what else you want from me? Now you just seem angry because I won't blindly accept your "evidence". I must be so evil to want to question what I'm told eh?

It helps to also read the text, as I suggested to you the last time I replied about this PDF...

Fig. 5 illustrates the main influence of the catenary action which is apparent in the deflection temperature curves when the beams survive up to large deflection. The fact that the axial compression force in the beam changes to tension force tends to stop the run-away caused by the applied load and material degradation. Depending on the temperature history during the fire scenario, the remaining material strength helps the heated beam to act in catenary to support the load, and tends to prevent run-away. The analysis was carried out using end-plate connections and a 50% load ratio.

Also this in the conclusions...

In this study, the case has been made that catenary action can enhance survival times for steel beams in fire, suggesting that such methods should be extended to include its effect where support conditions are appropriate.

And this...

Catenary action certainly occurs, and has been seen to affect a heated beam’s behaviour by preventing run-away deflection at high temperature plus applied load. The tensile axial force grows progressively as the deflection grows provided that some horizontal reaction stiffness exists. A change of the horizontal restraint stiffness can have a large effect on the behaviour of the beam at high deflection, and the loading on the beam can be carried very effectively as catenary tension replaces bending.

That was the second illustration you asked me to look at, and I have replied now concerning both of them, OK? Anything to make you happy PLB. So now, how about you read the text of that PDF, instead of just looking at the pretty pictures, and again explain where it says sagging trusses can pull in the columns?

How you get that idea from that PDF is a little mind boggling mate.

BTW if we're going to play the "you ignored my reply childishness", then here is one you didn't reply to.

www.abovetopsecret.com...

Can you answer that without getting your reply deleted by a Mod?

reply to post by ANOK


Where did I claim that this document sais that "says sagging trusses can pull in the columns"? Nowhere. What you are doing is making up a strawman argument. The reason you do this is because of the following:

You have been claiming for years now that sagging trusses can no put a pull-in force on columns. A pull-in force on columns does not mean that the columns are "pulled in", it means there is a force pulling on them.

Read that again.

A pull-in force on columns does not mean that the columns are "pulled in", it means there is a force pulling on them.

Let it sink in.

This document, proves beyond any doubt, that there can indeed be a pull-in force on columns. Now that you can not really get around the existance of this effect, you change the subject. You change it from "can there be a pull-in force" to "sagging trusses can pull in the columns".

It can mean two things. You either don't even understand the difference between the two. Or you are using deceptive debating tactics in an attemt to divert from the fact that, yes, indeed there can be a pull-in force, and you have been wrong all these years.

Now the other subject, the one you are trying to switch to all the time, for that I do not have any proof, like I have been telling you for years now. I only have proof that there can be a pull in froce, I can not prove if this force would have been enough to actually pull in the columns.

Get it now? Or are you going to ignore this post?

Originally posted by ANOK
www.abovetopsecret.com...

That is the wrong link. Not sure how that happened. This is the correct link back to page 13 in THIS thread...

www.abovetopsecret.com...

reply to post by ANOK


All the posts I linked are after that page you linked, and are in some cases in direct reply of what you are posting there. So no, I am not ignoring what you post, and yes you are ignoring what I post. Like my post above here.

ANOK, can you explain what happens when the lines cross the x-axis in figure 5b in that PDF? Why do you ignore this question?

reply to post by ANOK


No ANOK, either you are purposely trying to troll, or you are woefully misinformed about the facts.

Pancaking was first brought up as what started the collapse. FEMA in its initial investigation, as well as on PBS's special NOVA first hypothesized that "Pancaking" of the floors internally first, are what started the collapse.

This was initially called the "floor-truss failure" theory. You can read the synopsis here, of all places I'm going to, a Truther website.

911research.wtc7.net...

The truss failure theory, a key ingredient of the better known floor pancake theory, was endorsed by FEMA in its 2002 World Trade Center Building Performance Study . It invites us to imagine the floors assemblies detaching from their connections to the columns of the core and perimeter walls, precipitating a chain reaction of floors falling on one another. Without the lateral support of the floors, the columns, FEMA tells us, buckled and precipitated total building collapse.

911research.wtc7.net...
(the red commentary is a joke really, as there are many flaws and lies in it, but the report is there to look through for a refresher.)

As you can see, According to FEMA's initial idea, this is what was considered the INITIATOR of collapse. This became known as the "pancake theory." I'm surprised a Truther website has figured out what it means, and you are still in the dark in regards to the facts.

Even here, you can see a representation of the truss fail theory:


Start from 34:30.

NIST's investigation later showed that this was false. And to remind us what it said:

NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.

FEMA and NIST were tasked to investigate what caused the buildings to fail. FEMA's idea was wrong. NIST's theory came as the strongest one. You have to be able to have some reading comprehension abilities and a grasp of the English language to understand the full meaning and context.

from your own link on pancaking:

On September 11, 2001, World Trade Center buildings 1, 2 and 7 in New York City, collapsed as a result of terrorist attacks and the subsequent fires that followed. After a 3-year investigation by the National Institute of Standards and Technology, it was concluded that fire weakened the steel structure until the long bridge-like floor sections (called trusses) began to progressively sag. This sagging converted the downwards pull of the trusses into an inwards pull. This intensifying inwards pull on the walls eventually caused the outer columns of Tower 2, and later the inner columns of Tower 1, to buckle and fold, thus initiating the various progressive collapses.[14] 2,752 people died in the buildings, including 157 passengers and crew members who were aboard two hijacked airplanes that struck buildings 1 and 2, initiating fires in both, with debris initiating fires in building 7 upon the collapse of buildings 1 and 2. The buildings were a steel-frame design.

You are confusing the initiator and the resulting effect. Pancaking was not the initiator. That is what is being said. No one is arguing that. Pancaking did happen, AFTER initiation of collapse. . For some reason you are still making noise about this. Also, you cannot explain the evidence that backs up the facts. The stacked compressed floors found in the debris.

So how then, if you are going to be so adamant that floors did not stack on top of each other, then please oh please of pretty please, can you give me an idea of just how they got the floors to stack and compress each other.

Originally posted by -PLB-
ANOK, can you explain what happens when the lines cross the x-axis in figure 5b in that PDF? Why do you ignore this question?

Check the other link matey.

I can, but why don't I let the PDF you supplied itself explain it to you...

In the initial stages of heating the restraint from the surrounding structure tends to resist the expansion of a beam...

As I have been saying, heating of the truss/beam causes it to expand, and push against the columns. It cannot push the columns outwards, because "the surrounding structure tends to resist the expansion of a beam".

...The initial deflection is increased by this restrained expansion together with the thermal bowing caused by the temperature variation across the beam’s cross-section...

The truss can't expand outwards due to being pinned between columns, so the truss is deflected, it sags. How sad for your hypothesis?

Figure 5 explained here...

Fig. 5 illustrates the main influence of the catenary action which is apparent in the deflection temperature curves when the beams survive up to large deflection. The fact that the axial compression force in the beam changes to tension force tends to stop the run-away caused by the applied load and material degradation. Depending on the temperature history during the fire scenario, the remaining material strength helps the heated beam to act in catenary to support the load, and tends to prevent run-away. The analysis was carried out using end-plate connections and a 50% load ratio.

Figure 5b simply demonstrates the expansion of the beam, the blue lines are not the columns being pushed out, and pulled in lol, they are hypothetical.

In this study, the case has been made that catenary action can enhance survival times for steel beams in fire, suggesting that such methods should be extended to include its effect where support conditions are appropriate.

Catenary action certainly occurs, and has been seen to affect a heated beam’s behaviour by preventing run-away deflection at high temperature plus applied load. The tensile axial force grows progressively as the deflection grows provided that some horizontal reaction stiffness exists. A change of the horizontal restraint stiffness can have a large effect on the behaviour of the beam at high deflection, and the loading on the beam can be carried very effectively as catenary tension replaces bending.

www.fire-research.group.shef.ac.uk...

Again how do you get that sagging trusses can pull in columns, please quote the text that says that? Because the pretty picture are not demonstrating what you claim they are.

Originally posted by ANOK
Again how do you get that sagging trusses can pull in columns, please quote the text that says that? Because the pretty picture are not demonstrating what you claim they are.

It is pretty hopeless to continue with this. You keep repeating the same strawman argument, and you completely ignore for instance this post: www.abovetopsecret.com...
You act as if what is written there does not exist, and you keep repeating the same falsehoods. You are doing the same on other subjects. Since you keep ingoring everything I write I don't feel its very usefull to repeat it once again. So either react to the post I linked, or I am done. At least for now.

reply to post by -PLB-


How is it a strawman argument?

I am simply pointing out to you what it said in the PFD YOU gave me the link to. Nothing more, nothing less.

I asked you to quote where it said what you claimed, and you obviously can't do that, can you?

Again you link to pages in THIS thread, that I have been posting in pretty regularly. There is nothing new that I have not seen in my 9 years debating this on ATS, keep repeating the same stuff is not going to get you a different answer from me.

Haven't you noticed that every time you claim I ignored something it gives me a chance to reiterate what I have already said? I don't understand why you would do that? I really can't believe you actually believe what you're saying, that is the only conclusion I can come to, because no one could be that dense.

Seeing as you can't quote where it says sagging trusses can pull in columns I'm done trying to debate with you, so I'm just going to refer you back to this reply where I explain your PDF, and why you are wrong about what it says. Please refer to what I say here if you still insist it says sagging trusses can pull in columns....

www.abovetopsecret.com...

Originally posted by ANOK
Haven't you noticed that every time you claim I ignored something it gives me a chance to reiterate what I have already said? I don't understand why you would do that? I really can't believe you actually believe what you're saying, that is the only conclusion I can come to, because no one could be that dense.

Please stop insulting people. I have refrained from reporting you but you are persistently offensive when it is your understanding that is incorrect.

The reason we express despair at your endless repetition is that you don't seem to understand that you are wrong, you don't even seem to believe it's necessary for you to read relevant papers, just to guess and then insist your explanation is correct.

Seeing as you can't quote where it says sagging trusses can pull in columns I'm done trying to debate with you, so I'm just going to refer you back to this reply where I explain your PDF, and why you are wrong about what it says. Please refer to what I say here if you still insist it says sagging trusses can pull in columns....

I already quoted two reviewed, specific papers and showed you figures which show exactly what you say cannot happen:

www.abovetopsecret.com...

You can repeat yourself as many times as you like. It doesn't change the fact that you don't even seem to read arguments against your position.

reply to post by ANOK


Really Anok, go read that post I linked to. Try to understand it, and read it again. If you have problems understanding it you can ask a friend or you can ask me for helping to explain it. I really have no idea what else there is to do against this kind of denial.

Here, once again is my reply pointing out what PLB claims proves sagging trusses can pull in columns...

www.abovetopsecret.com...

PLB is ignoring my reply to his claim pretending I have not addressed it.

And here is my reply to exponent about the same thing...

www.abovetopsecret.com...

It says it all right there, I have no need to keep defending myself against this onslaught from the peanut gallery.

reply to post by ANOK


Push, not pull right? You are describing what happens to metal when it gets hot. It also loses its rigidity and strength because it 'expands'. This is why you cool steel the harden it. So, you are saying, in your own words, that the steel weakened. It did not, however, expand to the point that it would push so far outward it would break. The weakening of the steel caused it to 'sag' under the intense weight combined with the columns that were destoryed on impact.. The columns buckled and broke. When that happened, all of that weight suddenly was at the mercy of gravity and was not distributed. It fell. You are not defending anything as there is nothing to defend.

Middle school physics.

Originally posted by esdad71
Push, not pull right? You are describing what happens to metal when it gets hot.

Yes, yes I am.

Because the metal got hot, how could it have sagged if it didn't get hot?

Pushing and pulling of an object takes the same amount of energy. Knowing little physical truths like that go a long way in understanding what NIST claimed is pseudo-science.

If the trusses didn't push the columns out when it expanded, then it wouldn't pull them in either.

Sagging of the trusses can not create enough extra load to cause the columns to be pulled in. The idea is just ridiculous, and based on layman assumptions.

Even IF the trusses could do that the 1" and 5/8" bolts would have to be stronger than the columns were, and I can guarantee that they're weren't. If you think they were then you are in serious lala doh land. Why do you always ignore the connections when talking about the trusses sagging, it usually comes up when you need an excuse to ignore the resistance of the connections when you explain your "pancake collapse", eh?

You can't have it both ways, either the connections were the weak point, or they weren't. Which is it? If the connections survived the pull in I see no reason they would fail from another lightweight floor assembly falling on it. Especially the mechanical floors that had extra bracing to hold more load.

Do you even realise that a floor was made up of multiple trusses, that would have all had to heat up pretty evenly to cause all the trusses to sag.

Look how the floor is attached....





How could the columns fail before the connections? Or even the truss itself, as the literature PLB showed me, and as I pointed out, says.