Moderated Steel structures cannot globally collapse due to gravity alone

Heiwa said:
So if that really happened, part C would be sliced in two parts by part A from below. No crush down of part A by part C. No, a real upper cut from below of part C by part A.

But, rest assured. There is to little potential energy involved. Part C will just get stuck up on top on part A.

Because - steel structures cannot globally collapse or, rather, be crushed down due to gravity alone when you drop a small part of the structure on the remainder below!

I just said it in message #1 of this thread and nobody seems to able to prove it is wrong.
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With respect, this is just plain wrong.

Firstly - as has been pointed out to you many, many times - the towers employed a compiste structural system wherein the outer envelope, floors, inner core, and hat trusses acted together to ensure overall stability. A failure of any one of these therefore affects the stability of the overall structure. Your model assumes that each section is structurally stable (barring the fall itself and the immediate crush zone), which is patently not the case.

Secondly, and very closely linked to this, you continually refer to intact sections outwith the collapse and crush zones without ever demonstrating that the columns and beams - for this is what you focus on - are capable of accepting the loads without further failure.

Thirdly, you have been challenged numerous times to produce competent structural calculations in the face of what is best described as scathing criticism of your generalisations. You have failed to do so. That does not qualify as "not being able to prove you wrong". Rather, you have wholly failed to prove yourself correct.
 
Heiwa said:
So you missed my paper at http://heiwaco.tripod.com/nist3.htm ? Actually, you do not need math to prove it. Just common sense.
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Common sense fails for something that is several orders of magnitude larger than things people normally get to play with, pizza boxes for example, and where square laws and cube laws apply to the masses and forces involved in the full scale version.
 
Heiwa said:
... Just common sense. ...

Because - steel structures cannot globally collapse or, rather, be crushed down due to gravity alone when you drop a small part of the structure on the remainder below!

I just said it in message #1 of this thread and nobody seems to able to prove it is wrong.
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Einstein said,
"Common sense is the collection of prejudices acquired by age eighteen.”
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Next time use physics and you will find your conclusion is false.

Your statement of no steel building collapsing was proven wrong on 911. You can't say common sense is your tool and state false statements of steel structures can't globally collapse as seen on 911. It is irony your ideas were proven wrong with a full-scale model WTC on 911 with real murdering terrorists flying two planes at 470 and 590 mph with impact energies of 2,800,000,000 joules and 4,380,000,000 joules. Reality of fire’s effects on steel make your common sense approach not very scientific.

Your use of common sense and kids jumping on beds as your model of the non-collapse of the WTC is fantasy as the rest of the world uses physics and engineering.

The reason your paper is not rational is due to your initial setup which is not even common sense but nonsense.
Try to compress a lemon with another lemon. What happens? Both lemons compress.

Heiwa says, as he lays the ground work for his logic?
Now you have learnt a little what can happen when you drop anything on something and try to compress something. This basic knowledge is used in this paper.
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Due to the fact your paper was rejected for publication by all legitimate engineering journals around the world, what will you do next with your non-scientific paper?
 
funk de fino said:
Once the top section tipped enough it broke free - correct?

Or do the columns magically stay connected?
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No they don't. They will no doubt offset somewhat. On one side the columns might move in a little and put the weight on the floor but the other side would move outside the perimeter and remove a great deal of weight from the impacted floor. The core columns would be applying almost all their weight inside the core.

The theory is all about floors impacting floors and that would not happen all at once.
 
Christopher7 said:
A child can see WTC 7 fall straight down at near free fall [actual free fall for the first 105 feet].
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Christopher, I have heard you use this expression several times. It's an expression I've heard other conspiracy theorists use, and I find that interesting. It seems like the point you are trying to make is that, if we just used common sense, we'd be able to see things your way. Have I got that right?

You've admitted that you are not an expert in engineering or physics, or any of these things... in this thread, there are actual experts in these things exerting a lot of energy trying to explain where your conclusions are in error. But you seem to feel like you have a better grasp of the science than they do.

Why are you so certain about your conclusions? Is it all because of "common sense?" Do you truly think that common sense is infallible? In your mind, is there any possiblity that common sense can be wrong?

(Please believe me when I say that I am not trying to make a fool out of you or corner you with logic. I am sincerely curious about the answer to this question.)
 
Heiwa said:
Because - steel structures cannot globally collapse or, rather, be crushed down due to gravity alone when you drop a small part of the structure on the remainder below!
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Heiwa, since your common sense analysis doesn't refer in any way to the properties of steel, would you claim that this is true of any structure, or just of steel structures? If the latter, what's fundamentally different about steel structures that renders them immune to collapse when other structures aren't? Simple language and common sense analysis will do fine.

Dave
 
chris,

Christopher7 said:
What I can do is present arguments that the 4 ton frame sections could not be ripped apart and hurled up to 500 feet laterally by a falling building or debris.
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"... arguments ..."? Yes.

"... arguments that are the slightest bit convincing..."? Nope. Not in the least.

Christopher7 said:
I feel I have done that by establishing that the spring idea would not work and the fact that the building was collapsing a 5 or more floors per second which would drive sections down as they were torn loose. There would be some lateral ejection but nothing close to 400-500 feet.
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You have established none of those three things. "Stating" is not "establishing". Especially when one argument after another is so fundamentally flawed.

Christopher7 said:
No one here has a feasible answer so they just say "yes it can" and have shift to "not loud enough".
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You have a fascinating "perspective inversion". I've shown, with engineering calculations, that it is indeed feasible to store the energy necessary to toss those beams large distances thru multiple methods.

You keep saying "No, you can't". With ZERO argument except your personal incredulity.

YOU are the one simply saying "no, you can't."
 
Christopher7 said:
The theory is all about floors impacting floors and that would not happen all at once.
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Exactly how long do you think it should take? How long do the structural need to "think" about overwhelming loads suddenly shifted onto them before they fail?
 
Heiwa said:
So you missed my paper at http://heiwaco.tripod.com/nist3.htm ? Actually, you do not need math to prove it. Just common sense.
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You should notify the engineering and physics departments at all of the world's institutions of higher learning, as they may want to re-evaluate their curriculum requirements.

The upper part C is evidently smaller than the lower part A and as both parts destroy each other at contact assuming part C is dropped on part A; upper part C will be destroyed before lower part A. However, upper part C can only apply potential energy on lower part A. When part C just rests on lower part A there is no problem - part A is just compressed a little as compressive stresses in part A are just 0.3 of permissible stresses. That's how the towers were built. Now, if you drop part C on part A (how? - using a crane), there will be an impact but what contacts what? Two perimeter walls of part C will no doubt miss part A below and the other two walls will just contact the top floor of part A. It will not crush down part A. Just damage the top floor. Part A perimeter walls on the other hand will destroy the bottom floor of part C - the upper part! .

So if that really happened, part C would be sliced in two parts by part A from below. No crush down of part A by part C. No, a real upper cut from below of part C by part A.

But, rest assured. There is to little potential energy involved. Part C will just get stuck up on top on part A.

Because - steel structures cannot globally collapse or, rather, be crushed down due to gravity alone when you drop a small part of the structure on the remainder below!

I just said it in message #1 of this thread and nobody seems to able to prove it is wrong.
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Are you under the impression that simply because the components of the upper part are breaking into pieces that they lose all of their mass/energy? You like off-wall-experiments don't you? What do you think would be the outcome of releasing a few thousand pounds of sand (broken upper block) from a height of 3.7 meters onto your head? (Don't try this at home kids.)

Here is another one. What do you think would happen in a building of equivalent design and conditions present on 9/11, but the building is only 20 stories tall? Like WTC1 their are 11 stories in the upper block, and the upper block breaks through the damaged 9th floor down onto the 8th floor. What would your expected result be?
 
Architect said:
With respect, this is just plain wrong.

Firstly - as has been pointed out to you many, many times - the towers employed a compiste structural system wherein the outer envelope, floors, inner core, and hat trusses acted together to ensure overall stability. A failure of any one of these therefore affects the stability of the overall structure. Your model assumes that each section is structurally stable (barring the fall itself and the immediate crush zone), which is patently not the case.

Secondly, and very closely linked to this, you continually refer to intact sections outwith the collapse and crush zones without ever demonstrating that the columns and beams - for this is what you focus on - are capable of accepting the loads without further failure.

Thirdly, you have been challenged numerous times to produce competent structural calculations in the face of what is best described as scathing criticism of your generalisations. You have failed to do so. That does not qualify as "not being able to prove you wrong". Rather, you have wholly failed to prove yourself correct.
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Firstly it is recognized that the towers consisted of perimeter walls, core structure, floors and a hat truss.

The perimeter walls are steel columns connected by steel spandrels. The core structure is steel columns connected by steel beams. The floors are steel trusses carrying a steel/concrete composite; trusses are bolted to the perimeter walls and the core structure;

The hat truss is simply steel beams connecting perimeter walls and core structure at roof level.

All steel structure is designed with FoS > 3.

Secondly, the towers have great redundancy. You can remove parts of perimeter walls, core structure and floors anywhere and nothing happens except local falures! Example - a plane slices a perimeter wall and damages core structure and floors.

Thirdly, if you read my articles carefully you find a fair amount of structural calculations to confirm above and the stability of the parts. Also is described the step by step method to do proper structural damage analysis, the latter which neither NIST nor Bazant & Co has done.

It is pointed out that the alleged destruction is not a collapse but a crush down! An upper part C is alleged to drop on a lower part A.

As the upper part C consists of perimeter walls, core structure, floors and a hat truss it is then described what these sub-parts can inflict on the lower part A, which is similar to part C except for the hat truss.

And the result is quite clear; the stronger sub-parts of C and A will damage the weaker sub-parts, i.e. columns will damage floors and the interface at contact changes, which you have to analyse in the second step.

NIST and Bazant & Co deny this. They suggest that the bottom floor of part C remains intact and is capable of crushing/compressing part A perimeter walls, core structure and floors from top to bottom only assisted by gravity. This is ridiculous. The bottom floors of part C is the first to be affected at contact. So it will be destroyed. And also the second floor of part C may be destroyed if there is enough energy available to do that.

However, the available potential energy of the first step is quite small - say 340 kWh or 1.22 GJ. It is hardly enough for walls and core structure to penetrate the bottom floor of part C and top floor of part A. Thus, further destruction will be stopped already then! As most structure remains intact part C will just bounce on part A and then get stuck up top.

Finally, if you read my articles carefully you see that I describe a completely different destruction of the towers! Part C is destroyed prior dropping on part A. Part C is destroyed by controlled demolition producing a smoke and dust screen that in turn hides - or try to hide - the controlled demolition of part A that follows.

The controlled demolition of parts C and A is quite obvious to the trained eye.
I wonder how NIST and Bazant & Co could have missed that?
 
Dave Rogers said:
Heiwa, since your common sense analysis doesn't refer in any way to the properties of steel, would you claim that this is true of any structure, or just of steel structures? If the latter, what's fundamentally different about steel structures that renders them immune to collapse when other structures aren't? Simple language and common sense analysis will do fine.

Dave
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Yes, material of dropped part C and hit part A doesn't matter! It can be composite steel structures, pizza paper boxes, sponges of syntethic or natural fibres, lemons, etc. as described before. Part C can never crush down part A! There are two basic cases!

1. The energy applied is only sufficient to elastically deform parts A and C. Result - part C bounces on part A.

2. The energy applied is sufficient to cause failures of parts A and C. Then parts A and C are damaged at the contact area, the interface changes and the energy is consumed by local faulures of both parts A and C.

Quite basic actually. Part C can never destroy part A.
 
Christopher7 said:
No they don't. They will no doubt offset somewhat. On one side the columns might move in a little and put the weight on the floor but the other side would move outside the perimeter and remove a great deal of weight from the impacted floor. The core columns would be applying almost all their weight inside the core.

The theory is all about floors impacting floors and that would not happen all at once.
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So as the top section tilted none of the perimeter or core columns broke at the connections as they bent? They all stayed connected?

The top section tipped it did not skew horizontally.

The theory is about the "load" from the floors above hitting the uppermost floor below. Not the floors themselves. the top section only has to fall and hit the floor in one place for that load to be transferred.
 
3bodyproblem said:
No, you need math. Without out it you have nothing. That's how things work.
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More to the point, the physical world behaves in ways that mathematics and only mathematics can actually describe.

Maths are a LANGUAGE OF DESCRIPTION.

If you don't speak that language, you don't have the nouns and verbs to even begin to talk about many things.
 
GStan said:
Are you under the impression that simply because the components of the upper part are breaking into pieces that they lose all of their mass/energy?
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Good that you accept that the upper part may break up. Evidently the mass remains the same ... but it is then in smaller parts. Interface changes. So you have to analyse what the smaller parts can do. Part of structural damage analysis!

Energy is consumed when you break parts (it becomes heat). You get hot and sweat when you work or apply energy.

So if, as alleged part C drops due to gravity and impacts part A, energy is consumed and becomes heat. The result? Little C cannot destroy big A because there is too little energy available All energy is consumed by local failures in interface A/C. C stops on top of A. Happens everytime. Except WTC911. So how could C destroy A on 911? Consider evil CD.
 
Heiwa said:
Actually, you do not need math to prove it. Just common sense.
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Heiwa, this is a simple question along the same lines as the one I posed to Chirstopher. Don't be offended; I just want to hear your honest answer.

Do you believe that common sense and math are equivalent, in the sense that if common sense tells you something, the math should check out? Do you believe common sense is absolutely trustworthy in all cases?

For example... with the JFK theories, one of the arguements that Ozwald couldn't have shot JFK is that his head jerked in the opposite direction of the bullet. That goes completely against common sense. Well, it turns out common sense was wrong, in this particular case. I've seen demonstrations (they do it on the P&T show) of a bullet going through an watermelon, turns out the force of the bullet pushes the object towards the bullet. Now, this has nothing to do with WTC, but it's the best example I can think of how common sense tells us something should happen, when in reality the complete opposite happens.

So, what I'm wondering is, do you agree with me that common sense can sometimes leads us to the wrong conclusions? If not, why not? I'm not trying to trap you, just looking for an honest answer.
 
L The Detective said:
Christopher, I have heard you use this expression several times. It's an expression I've heard other conspiracy theorists use, and I find that interesting. It seems like the point you are trying to make is that, if we just used common sense, we'd be able to see things your way. Have I got that right?
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L, here's a summary I assembled a couple of years ago of Christopher 7's belief that "common sense" trumps science, physical evidence, etc.
 
Heiwa

I've got a question for you.

It was evident in the "crush down" (your term, I'd be just as happy with the generic term "collapse") of the towers that the crushing happened successively at each floor as the rubble descended.

My question to you: how do you explain this. Do you believe that each floor was blown with demolitions as the upper block's debris arrived at that floor?

My ultimate question is going to be "why did each & every one of about 85 collapses happen at the upper story, and not at some lower floor?"

This phenomenon happened on both towers, for every story, after the crush down got established.

What is your explanation for this?

tom
 
L The Detective said:
Heiwa, this is a simple question along the same lines as the one I posed to Chirstopher. Don't be offended; I just want to hear your honest answer.

Do you believe that common sense and math are equivalent, in the sense that if common sense tells you something, the math should check out? Do you believe common sense is absolutely trustworthy in all cases?

For example... with the JFK theories, one of the arguements that Ozwald couldn't have shot JFK is that his head jerked in the opposite direction of the bullet. That goes completely against common sense. Well, it turns out common sense was wrong, in this particular case. I've seen demonstrations (they do it on the P&T show) of a bullet going through an watermelon, turns out the force of the bullet pushes the object towards the bullet. Now, this has nothing to do with WTC, but it's the best example I can think of how common sense tells us something should happen, when in reality the complete opposite happens.

So, what I'm wondering is, do you agree with me that common sense can sometimes leads us to the wrong conclusions? If not, why not? I'm not trying to trap you, just looking for an honest answer.
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I like math! Math is a science of space and numbers; arithmetic, algebra, geometry, you know. I just use it as a tool. To verify physical events, e.g. ship collisions and structural failures. Math can translate them into an abstract form that can assist clarifying and understanding them.
Common sense is not a science. Nor is clear thinking. I would suggest that common sense is neutrality of estimation of facts and clear thinking promotes knowledge. And maths is a tool to verify the results. And problems are solved. I have worked in such manner for 40 years. So common sense will not lead you to the wrong conclusions.
But bad passions, ill will, malicious intent and confused thinking surely will. I have encountered plenty of those amongst unhappy people that produce disastrous enmities and hatred. I just feel sorry for them. They are a miserable lot.
I am just a happy guy that nobody can really stress. Common sense and maths work for me.
 
Heiwa said:
Firstly it is recognized that the towers consisted of perimeter walls, core structure, floors and a hat truss.

The perimeter walls are steel columns connected by steel spandrels. The core structure is steel columns connected by steel beams. The floors are steel trusses carrying a steel/concrete composite; trusses are bolted to the perimeter walls and the core structure;

The hat truss is simply steel beams connecting perimeter walls and core structure at roof level.
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You disregard both the point to you and the understanding of a composite structure. As has been explained to you several times before, the various structural elements act together - the parallel would be a girder truss - in order to ensure overall stability. If one element is compromised then the entire building is at risk.

Moreover you disregard the role of the hat trusses. These do not simply connect the inner and outer structures, but rather serve to address issues such as the overturning moment. That the ultimately served to redistribute some of the external envelope load to the columns is of note, but not their design function.

If you fail to follow this fairly basic premise then I cannot understand how you can purport to analyse the failure sequence.

All steel structure is designed with FoS > 3.
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Factors of safety have been dealt with at some considerable length before, are you sure you want to cover this one again? It'll be painful for you, trust me.

Secondly, the towers have great redundancy. You can remove parts of perimeter walls, core structure and floors anywhere and nothing happens except local falures! Example - a plane slices a perimeter wall and damages core structure and floors.
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Evidence? Calculations?

Thirdly, if you read my articles carefully you find a fair amount of structural calculations to confirm above and the stability of the parts. Also is described the step by step method to do proper structural damage analysis, the latter which neither NIST nor Bazant & Co has done.
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Actually, you don't. These aren't competent structural calculations of the type required to analyse a complex building of this type or indeed the failure mode. You've been asked to provide real calculations many, many times but have singularly failed to do so.

It is pointed out that the alleged destruction is not a collapse but a crush down! An upper part C is alleged to drop on a lower part A.

As the upper part C consists of perimeter walls, core structure, floors and a hat truss it is then described what these sub-parts can inflict on the lower part A, which is similar to part C except for the hat truss.

And the result is quite clear; the stronger sub-parts of C and A will damage the weaker sub-parts, i.e. columns will damage floors and the interface at contact changes, which you have to analyse in the second step.

NIST and Bazant & Co deny this. They suggest that the bottom floor of part C remains intact and is capable of crushing/compressing part A perimeter walls, core structure and floors from top to bottom only assisted by gravity. This is ridiculous. The bottom floors of part C is the first to be affected at contact. So it will be destroyed. And also the second floor of part C may be destroyed if there is enough energy available to do that.
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You completely disregard a number of key issues, not least the loss of overall structural integrity as part of the composite "girder truss" design, above. You also fail to provide any meaningful structural calculations to show that the strength of the lower part of the building has sufficient redundancy to stand the additional and much changed load paths.

However, the available potential energy of the first step is quite small - say 340 kWh or 1.22 GJ. It is hardly enough for walls and core structure to penetrate the bottom floor of part C and top floor of part A. Thus, further destruction will be stopped already then! As most structure remains intact part C will just bounce on part A and then get stuck up top.
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Bounce. Hmmm.

Finally, if you read my articles carefully you see that I describe a completely different destruction of the towers! Part C is destroyed prior dropping on part A. Part C is destroyed by controlled demolition producing a smoke and dust screen that in turn hides - or try to hide - the controlled demolition of part A that follows.
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THat doesn't actually make sense, you know.

The controlled demolition of parts C and A is quite obvious to the trained eye.
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How would you know? You're not trained in building structures or controlled demolition. Or fire engineering. Or architecture.
 
Safety Factors

Just to prove that I'm a glutton for punishment, I've given some considerable thought to Heiwa's throwaway comment regarding safety factors in the steelwork.

NIST tested the steel recovered from WTC (which in itself is of interest, as CTers usually claim it was all whisked away to China with unseemly haste). NIST NCS STAR 1-3D (http://www.fire.nist.gov/bfrlpubs/fire05/PDF/f05158.pdf) confirms a range of actual values:

- Core webs ranged from as low as 31.1 to 41.9 ksi, ie. 86 to 116% of specificed strength.

- Core flanges ranged from 32.4 to a high 53.4 ksi, ie. 90 to 146% of specified strength.

Setting to one side the 31.1 and 32.4 ksi results, inasmuch as a small proportion of columns below failure point are unlikely to lead to any wider problem, let's take the lower maximum of 116% specified value.

Now, the NIST Demand to Capacity Ratios (DCR) are based upon specified strengths and NIST themselves note that there is effectively spare capacity up to actual (but varying) yield point/strength.

Core columns in WTC typically had a Demand to Capacity Ratio (DCR) of 0.83, ie a safety factor of 1/0.83=1.20. Now let's assume assume that the steel has an additional 16% beyond minimum yield value. This would reduce the DCR to 1.16/.83=1.4.

In other words we could increase the loads in these areas by up to 40% before yield point was reached and plastic (permanent) deformation begins. Of course this figure has lots of variables - most of the steel webs did not have such a high yield factor, some areas had DCRs well in excess of 0.83, and so on.

What we don't do is then add any significant additional allowance for tensile strength because (a) yield failure is already occuring and (b) gravity loads will be compressive, not tensile.

As I frequently mention, one thing we also have to appreciate is that the structure of WTC is complex; in addition to dead and live loads, it will be dealing with (for example) transverse and shear loadings from the wind. There will be a degree of torsion due to differential loading. And so on. We would therefore have to look at the exact steelwork design in considerable detail before we could determine a safety factor for each. That's why engineers earn a lot of cash, and why complex modelling software was developed.

Nevertheless it is clear that the actual capacity of the core is not going to be anything like 400% or 4:1 before irreversible damage and failure begin to occur.

But in any event the above calculations all assume an intact core, and we know from the various NIST studies and eyewitness evidence that the cores suffered damage - around a third. This will obviously have reduced loadbearing capacity still further, and a simple pro-rata reduction of (say) 30% is likely to be wrong because the damage is concentrated in localised areas and hence these areas will be susceptible to accelerated failure under loads.

I shall, as ever, await Heiwa's next attempt to display his intuitive grasp of mechanics and structures with the greatest of interest.

Health Warning: I'm an architect, not a structural engineer. I only need to know the big picture stuff and the basics in order than I can instruct/co-ordinate/know when to listed to real specialists.* Some of the engineers may therefore want to add to this post.

(*) I do not include Heiwa in this definition of "engineer" or "specialist".
 
tfk said:
Heiwa

I've got a question for you.

It was evident in the "crush down" (your term, I'd be just as happy with the generic term "collapse") of the towers that the crushing happened successively at each floor as the rubble descended.

My question to you: how do you explain this. Do you believe that each floor was blown with demolitions as the upper block's debris arrived at that floor?

My ultimate question is going to be "why did each & every one of about 85 collapses happen at the upper story, and not at some lower floor?"

This phenomenon happened on both towers, for every story, after the crush down got established.

What is your explanation for this?



tom
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Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews?page=1
 
Heiwa said:
I like math! Math is a science of space and numbers; arithmetic, algebra, geometry, you know. I just use it as a tool. To verify physical events, e.g. ship collisions and structural failures. Math can translate them into an abstract form that can assist clarifying and understanding them.
Common sense is not a science. Nor is clear thinking. I would suggest that common sense is neutrality of estimation of facts and clear thinking promotes knowledge.
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I must admit, I don't enjoy math. But as you say, it's a useful tool. We agree on that.

So to you, "common sense" is neutrality. I see. So when you are asking someone to use common sense when looking at certain facts, what you are really asking is to look at the facts in an unbiased way? Do I have that correct?

By "clear thinking," do you mean rationality?

Heiwa said:
And maths is a tool to verify the results. And problems are solved. I have worked in such manner for 40 years. So common sense will not lead you to the wrong conclusions.
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I see. So what you are saying here is "being unbiased won't lead you to the wrong conclusions." Did I interpret that correctly?

Heiwa said:
But bad passions, ill will, malicious intent and confused thinking surely will. I have encountered plenty of those amongst unhappy people that produce disastrous enmities and hatred. I just feel sorry for them. They are a miserable lot.
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So basically what you're saying is that negative emotions can cloud judgment and lead to the wrong conclusions... I agree with that. Although, I would go a step farther and say that applies to positive emotions too. Personally, I think that any emotions can cloud "clear thinking," or as I say it rational judgment.

Heiwa said:
I am just a happy guy that nobody can really stress. Common sense and maths work for me.
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I've read many of your posts, and I certainly don't doubt this assertion! You seem like a happy guy.

I think I'm talking about a different kind of common sense from you, though. What I'm talking about, well... maybe another way to say it would be "instinct." For example, in the case of JFK and the watermelon, people wouldn't think that the watermelon would blow back in the opposite direct of the bullet that goes through it. That defies common sense, or rather, it defies people's "instinctive belief."

I bring that up, because when I see some people using the phrase "even a child would see it," to me it seems what they are talking about is "instinctive belief." In other words, what they seem to be saying is that I should instinctively know that what they are saying is true.

What do you think? Do you agree with me that our instincts can sometimes decieve us?
 
Architect said:
You disregard both the point to you and the understanding of a composite structure. As has been explained to you several times before, the various structural elements act together - the parallel would be a girder truss - in order to ensure overall stability. If one element is compromised then the entire building is at risk.

Moreover you disregard the role of the hat trusses. These do not simply connect the inner and outer structures, but rather serve to address issues such as the overturning moment. That the ultimately served to redistribute some of the external envelope load to the columns is of note, but not their design function.

If you fail to follow this fairly basic premise then I cannot understand how you can purport to analyse the failure sequence.
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Evidently the various structural elements act together. That's what structural analysis is all about. Where does the forces go? What bending moments are produced? What happens at the joints?
Structural damage analysis is more complex as the structure changes with each failure, so you have to re-do the complete analysis after each failure. Neither NIST nor Bazant & Co has done that.
But I have!
It is of course preposterous to assume that the initial failure is that all 280+ columns fail and that part C free falls on part A, but it can be analysed ... as I have done. And the result is that the columns will damage the floors ... and after that crush down is arrested.
The hat truss should remain intact as it is not in contact with part A.
Have you ever done any structural damage analysis?
 
Architect said:
Just to prove that I'm a glutton for punishment, I've given some considerable thought to Heiwa's throwaway comment regarding safety factors in the steelwork.

NIST tested the steel recovered from WTC (which in itself is of interest, as CTers usually claim it was all whisked away to China with unseemly haste). NIST NCS STAR 1-3D (http://www.fire.nist.gov/bfrlpubs/fire05/PDF/f05158.pdf) confirms a range of actual values:


As I frequently mention, one thing we also have to appreciate is that the structure of WTC is complex; in addition to dead and live loads, it will be dealing with (for example) transverse and shear loadings from the wind. There will be a degree of torsion due to differential loading. And so on. We would therefore have to look at the exact steelwork design in considerable detail before we could determine a safety factor for each. That's why engineers earn a lot of cash, and why complex modelling software was developed.

Nevertheless it is clear that the actual capacity of the core is not going to be anything like 400% or 4:1 before irreversible damage and failure begin to occur.

But in any event the above calculations all assume an intact core, and we know from the various NIST studies and eyewitness evidence that the cores suffered damage - around a third. This will obviously have reduced loadbearing capacity still further, and a simple pro-rata reduction of (say) 30% is likely to be wrong because the damage is concentrated in localised areas and hence these areas will be susceptible to accelerated failure under loads.

I shall, as ever, await Heiwa's next attempt to display his intuitive grasp of mechanics and structures with the greatest of interest.

Health Warning: I'm an architect, not a structural engineer. I only need to know the big picture stuff and the basics in order than I can instruct/co-ordinate/know when to listed to real specialists.* Some of the engineers may therefore want to add to this post.

(*) I do not include Heiwa in this definition of "engineer" or "specialist".
Click to expand...

When building ships every steel component has its certificate of testing, etc. so you know what you use. But we now and then double check. No big deal.

The WTC core structure was built with a FoS >3 so it was extremely strong. Wall perimeter was same - including dynamic wind loads FoS was still >3.

In shipbuilding we actually use smaller FoS because we use quite big design loads, particularly the dynamic ones. Where there are no dynamic loads we use FoS about 3. Good practice! But that's just for design.

Structural damage analysis is a completely different matter. When a component fail ... it cannot fail again as it does not carry any load after failure. So there is no such thing as an accelerated failure under load. No, you have to re-analyse and see where the load on the failed part has gone.

I doubt very much that you have done any structural damage analysis and conclude you do not know what you are talking about.
 
L The Detective said:
So to you, "common sense" is neutrality. I see.

1. So when you are asking someone to use common sense when looking at certain facts, what you are really asking is to look at the facts in an unbiased way? Do I have that correct?

2. By "clear thinking," do you mean rationality?

So basically what you're saying is that negative emotions can cloud judgment and lead to the wrong conclusions... I agree with that. Although, I would go a step farther and say that applies to positive emotions too. Personally, I think that any emotions can cloud "clear thinking," or as I say it rational judgment.



I've read many of your posts, and I certainly don't doubt this assertion! You seem like a happy guy.

I think I'm talking about a different kind of common sense from you, though. What I'm talking about, well... maybe another way to say it would be "instinct." For example, in the case of JFK and the watermelon, people wouldn't think that the watermelon would blow back in the opposite direct of the bullet that goes through it. That defies common sense, or rather, it defies people's "instinctive belief."

I bring that up, because when I see some people using the phrase "even a child would see it," to me it seems what they are talking about is "instinctive belief." In other words, what they seem to be saying is that I should instinctively know that what they are saying is true.

3. What do you think? Do you agree with me that our instincts can sometimes decieve us?
Click to expand...

1. Yes, more or less! But I do not use the word unbiased. Neutral or impartial is better.

2. I said that clear thinking promotes knowledge. Rationale is similar.

3. Instinct is the opposite to rationale so instinct may deceive you, of course. But you do not use instinct when doing structural analysis. But inspecting structures, instinct may be useful! You sniff around! Is everything OK? Sometimes you just feel there is a defect somewhere. This combination of instinct and rationale is quite helpful.

You see, I started out with this WTC/911 matter as some children, having seen some videos, couldn't sleep! They thought - instinct - the house would just crush them. So I explained to them how structures work! For that very simple language was required, but they understood and now sleep well. And I published the lecture on my web site. The lecture has becomea little more advanced since but the message is the same.
 
bill smith said:
Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews?page=1
Click to expand...

I haven't got a clue. But some sudden application of energy - high, sudden presssure on the whole surface - is required to pulverize the floors. Gravity forces/loads, e.g. steel columns punching holes in the floors cannot pulverize them.
 
bill smith said:
Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews? page=1
Click to expand...

PPS Repost of defective nanotechnology link.

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology
 
the head of the hmmer

Bazant talks about a 0.9 m inital layer of compacted rubble acting as the head of the hammer so to speak.As I uncerstand it he indicates that this layer grows as the collapse progresses. But to keep a layer of rubble like that compacted you need a binder of some kind and there is no such binder imaginable at the WTC.

This compacted rubble would meet the upstanding core clumns which would break it uo further and cause the dissociated aggregate to behave more ike a liquid, flowing over, around and between the Core columnns surely ? In this fashion no coherent force could b exerted on the massive Lower columns.
 
Heiwa said:
I haven't got a clue. But some sudden application of energy - high, sudden presssure on the whole surface - is required to pulverize the floors. Gravity forces/loads, e.g. steel columns punching holes in the floors cannot pulverize them.
Click to expand...

There was extremely little concrete left in the rubble on the ground. Even if the force of the collapse had broken it up thre should have been millions of pieces of concrete strewn everywhere quite apart from the percentage that had been pulverised.
If you look at the attached animated gif- allow it to load and cycle a few times you get the impression of how little rubble there WAS on the ground after the collapse. Even more tellingly, reverse the view in your mind and watch the Two biggest Towers in the world reassemble hemselves from the paltry few sticks and stones we can see in the image. Always remembering that the inside of the buildng was full of structure as well, including 110 one-acre 4'' thick concrete floors..

http://www.acebaker.com/9-11/HTR/web-content/Images/HTRTitleAnim.gif animated gif
 
bill smith said:
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well.
Click to expand...

Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.

bill smith said:
Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?
Click to expand...

At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave
 
bill smith said:
Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?
Click to expand...

You posted this before but I think the replies got lost in a lot of shouting by bob_the_analyst. Let's try again :

1) This all depends on your take on concrete "pulverisation". How much and how fine. I believe you were asked once before, but I do appreciate that as a Truther here your posts attract a lot of replies. So - what is your take on this subject?

2) Why, by all that's Holy, would anybody want to even try this? Blowing the floors to pieces would have no bearing on the collapse, and would be a pointless but massive operation that could be detected in advance or go wrong in practice.
 
bill smith said:
PPS Repost of defective nanotechnology link.

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology
Click to expand...

What does the content of that video have to do with anything that can cause the collapse of one of the largest buildings in the world? Nothing.

All discussion of nano-anything in our context is silly.

Thermite/thermate doesn't explode. To the extent that something called nano-thermite exists and can be said to explode, it also makes the same noise associated with any explosive; BOOM. Nobody heard any explosions at WTC consistent in loudness and timing with man-made demolition

The idea that any destructive device was built into any of the WTC towers in advance is silly.

The idea that any destructive device was installed just before 9/11 is silly.

As someone that was involved with several total floor renovations on Manhattan's larger buildings, the idea of anyone doing anything involving people and materials and access with the certainty that they wouldn't be found-out is silly and it shows the complete ignorance of everything on the part of the silly people that make these claims.
 
Dave Rogers said:
Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.



At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave
Click to expand...

Bill's missing something else: Thermite needs iron to react. Even if someone impregnated concrete with it, how's it going to ignite? The only places it would react at would be where steel is. Someone else can apply that to the specific construction of the towers - did the concrete have steel rebar in it, or was the concrete simply sitting on top of a floor "pan"? I don't remember - but the point is that trying to "impregnate" concrete with "nano" thermite would be silly because it wouldn't necessarily be applying it to where the steel is.

This is yet another attempt to shoehorn one of Steven Jones's silly proposals into the towers collapse. Thermite needs to be applied to the steel to react. Otherwise, it's not going to react. That's just basic chemistry.
 
Dave Rogers said:
Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.



At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave
Click to expand...

The incredibly finely-ground thermite could have been added to some kind of sprayable gel. Something hat would hold the nanothermite layer in place. The gel itself would likely also be a nano material which would mean that it could be drawn into the concrete by capilliary action or under pressure, The gel cold hve been applied to the underside of the floors by workers or robot srayers on rails. Detonators might have been also attched to the underside of the floors too.

If you read Kevein Ryan's paper on nano-thermite you will see that it's properties are greatly enhanced qua speed of ignition and coverage. Nano materials are so small that they can enter human cells, so the much larger structures in concrete would pose no problems at all. At 5,700 degrees C the water residue would most likely boil instantly explode and pulverise most of the concrete into a fine dust upon ignition. It's good to have scientists such as yourself for plugging in the numbers.

As for why they had to pulverise the concrete I can think of a couple of possibilities. One : to shroud and conceal the nature of the collapse and Two: Two: because pulverising the floors may have promoted a more efficent demolition
There iis a third less likely possibility but that is a story all on it's own.
 
Heiwa said:
1. Yes, more or less! But I do not use the word unbiased. Neutral or impartial is better.
Click to expand...

All right. In that case, those words are probably better to use than common sense, since that term may be a bit misleading. When I hear common sense, I think it means general knowledge, or instinct. I think most people generally have the same response. But in any case, I know what you personally mean now by those words.

Heiwa said:
2. I said that clear thinking promotes knowledge. Rationale is similar.
Click to expand...

What do you mean by "clear thinking," exactly? I was only guessing that you meant rationality.

Heiwa said:
3. Instinct is the opposite to rationale so instinct may deceive you, of course. But you do not use instinct when doing structural analysis. But inspecting structures, instinct may be useful! You sniff around! Is everything OK? Sometimes you just feel there is a defect somewhere. This combination of instinct and rationale is quite helpful.
Click to expand...

So it seems we agree. Instinct can be helpful, but at the same time it can lead you astray. I would say that for practical things, instinct is a good "starting place," but if those instincts should come under question we have to be prepared to re-examine them, and dismiss them if the science disagrees.

Heiwa said:
You see, I started out with this WTC/911 matter as some children, having seen some videos, couldn't sleep! They thought - instinct - the house would just crush them. So I explained to them how structures work! For that very simple language was required, but they understood and now sleep well. And I published the lecture on my web site. The lecture has becomea little more advanced since but the message is the same.
Click to expand...

I see, that's interesting. So what you're saying is, the children's instinct about how buildings would fall was wrong, and you corrected them using science? Am I correct in understanding that?

May I ask you another question? What led you to originally suspect that 911 was an inside job? Was it rationality, or instinct? And by "originally," what I mean is, the very first time you had suspicious thoughts, which do you identify as being the cause? The reason I ask is because, it seems that for most people, the answer would be "instinct," because they instinctively knew that buildings couldn't fall that way, or some other such thing. But maybe it's different for you?
 
BigAl said:
What does the content of that video have to do with anything that can cause the collapse of one of the largest buildings in the world? Nothing.

All discussion of nano-anything in our context is silly.

Thermite/thermate doesn't explode. To the extent that something called nano-thermite exists and can be said to explode, it also makes the same noise associated with any explosive; BOOM. Nobody heard any explosions at WTC consistent in loudness and timing with man-made demolition

The idea that any destructive device was built into any of the WTC towers in advance is silly.

The idea that any destructive device was installed just before 9/11 is silly.

As someone that was involved with several total floor renovations on Manhattan's larger buildings, the idea of anyone doing anything involving people and materials and access with the certainty that they wouldn't be found-out is silly and it shows the complete ignorance of everything on the part of the silly people that make these claims.
Click to expand...

The video gives people an opportunity to really understand
nano-technology rather than just vaguely thinking 'very small'.
If you want to have a idea about how effective and different from standard thermite the nano version is this isessential viewing, just as Kevin Ryan's paper on nano thermite is essential readng.

http://www.journalof911studies.com/volume/2008/Ryan_NIST_and_Nano-1.pdf NIST and nano-thermite

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology
 
Heiwa said:
When building ships every steel component has its certificate of testing, etc. so you know what you use. But we now and then double check. No big deal.

The WTC core structure was built with a FoS >3 so it was extremely strong. Wall perimeter was same - including dynamic wind loads FoS was still >3.
Click to expand...

No. I've just posted a detailed explanation of why the actual safety factor is not 3, including facts/figures. You have blindly stated "FoS>3" without any explanation. Please clarify, in detail, how you arrived at this figure.
 
Apparently this nano-thermite is also weightless and invisible. No one has done any calculations to show how much steel a Kg of thermite will melt even when half the calculation has been done for them. Infact truthers don't even know which parts of the structure required to be cut for collapse. Imagine if all the floors needed thermite to collapse. 1 litre of thermite weighs 2.1Kg. You'd need truckloads of the stuff. Imagine the poor NWO operatives lugging all that up the back stairs!
 
bill smith said:
The incredibly finely-ground thermite could have been added to some kind of sprayable gel. Something hat would hold the nanothermite layer in place. The gel itself would likely also be a nano material which would mean that it could be drawn into the concrete by capilliary action or under pressure, The gel cold hve been applied to the underside of the floors by workers or robot srayers on rails. Detonators might have been also attched to the underside of the floors too.

If you read Kevein Ryan's paper on nano-thermite you will see that it's properties are greatly enhanced qua speed of ignition and coverage. Nano materials are so small that they can enter human cells, so the much larger structures in concrete would pose no problems at all. At 5,700 degrees C the water residue would most likely boil instantly explode and pulverise most of the concrete into a fine dust upon ignition. It's good to have scientists such as yourself for plugging in the numbers.

As for why they had to pulverise the concrete I can think of a couple of possibilities. One : to shroud and conceal the nature of the collapse and Two: Two: because pulverising the floors may have promoted a more efficent demolition
There iis a third less likely possibility but that is a story all on it's own.
Click to expand...

With respect, this is all unsubstantiated conjecture.

On the one hand, we have a highly detailed series of models demonstrating how failure could - did - occur due to damage to structural steelwork and fire damage. It has been reviewed and discussed by learned bodies such as the universities at some length, and the results not found particularly wanting.

What you have is unsubstantiated conjecture. Perhaps it could be some sort of spray-on therm*te gel, but then perhaps it could also be a martian death-ray. Unless you have tangible evidence then it comes to naught.

Moreover in discussing the reason for pulverisation (your term) of the concrete, you completely overlook the impact (pun inteded) of a fall from a great height.
 
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