Layman's terms please! Tower collapse issue

[DGM]

The load does not disappear though. It's redistributed to other columns. Once enough of these are compromised the rest will fail in rapid succession. Really simple if you think of a building as a 'system'.

 

[Dave Rogers]

If the upper block is supposed to impact the lower structure after alleged free fall, evidently the columns of the upper block must drop straight on the columns on the lower structure ... and not slip off. Otherwise there is no solid, instantaneous impact that can cause a shock wave that shakes the columns below into pieces.

Anything else is just ... well dropping a bale of wool on a very solid lower structure. No impact! The upper part misses the relevant structure below.

If the columns of the upper block miss the columns of the lower block, they hit the floor slab below. Your argument, therefore, is that the floor slab is strong enough to withstand the impact of the columns of the upper block. You may want to say that it isn't, but in fact that's your argument, and it's insane. Your "bale of wool" doesn't even have a flat lower surface to distribute the imp



Sorry, I gave up half way through writing this post. Heiwa's argument here is utterly insane, and there's no way it could possibly be mistaken for a sane argument. There is simply no way that communication is possible with someone who could believe any of it.

Dave

 

[Minadin]

The upper block is 4 000 m² large where the primary load bearing columns occupy 5-6 m² cross area. Same with the lower structure.

If the upper block is supposed to impact the lower structure after alleged free fall, evidently the columns of the upper block must drop straight on the columns on the lower structure ... and not slip off. Otherwise there is no solid, instantaneous impact that can cause a shock wave that shakes the columns below into pieces.

Anything else is just ... well dropping a bale of wool on a very solid lower structure. No impact! The upper part misses the relevant structure below.

Re peer review. Some of you are my peer reviewers. The other greenhorns I just ignore.

Re floors - they are not primary load bearing structure of any static loads. They just transmit weights on them to the columns.

The columns themselves may have only taken up a small % of the overall footprint, but the floors and anything in between such as partition walls did actually take up the rest of the footprint. As you yourself have noted, the composite floor structure (concrete, metal decking, bar joists) transfers loads to the core columns as well as the outer envelope. It doesn't "miss" - nor are the floors themselves completely irrelevant. They're just inconvenient for your fantasy. So what do you think happens when the floors are impacted?

Continuing with this wool analogy is beyond stupid:

Anything else is just ... well dropping a bale of wool on a very solid lower structure. No impact! The upper part misses the relevant structure below.

And in fact I've decided to add that to this month's list of dubious nominations.

 

[Architect]

Sorry, I gave up half way through writing this post. Heiwa's argument here is utterly insane, and there's no way it could possibly be mistaken for a sane argument. There is simply no way that communication is possible with someone who could believe any of it.

Seconded.

It's all getting a bit ChristopherA, don't you think?

 

[ElMondoHummus]

Sorry, I gave up half way through writing this post. Heiwa's argument here is utterly insane, and there's no way it could possibly be mistaken for a sane argument. There is simply no way that communication is possible with someone who could believe any of it.

Dave

Seconded.

It's all getting a bit ChristopherA, don't you think?

Well, there is some value in responding at points to repititious demonstrations of insanity: You get the truth out. You may no longer be talking to the fantasy peddler, but the words still stand for other people reading the thread.

But don't take that to mean I think you all should respond endlessly. I absolutely agree that going around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and AROUND is futile. All I'm saying is that a word or two here and there helps the bystanders, especially with esoteric subjects or in depth arguments.

 

[Dave Rogers]

But don't take that to mean I think you all should respond endlessly. I absolutely agree that going around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and around and AROUND is futile. All I'm saying is that a word or two here and there helps the bystanders, especially with esoteric subjects or in depth arguments.

Yeah, but I did that in post #2.

Dave

 

[ElMondoHummus]

Yeah, but I did that in post #2.

Dave

Oh, yes, and that's fine. All I was saying was that there's some value in measures responses. That's all.

 

[Heiwa]

The load does not disappear though. It's redistributed to other columns. Once enough of these are compromised the rest will fail in rapid succession. Really simple if you think of a building as a 'system'.

You are 100% right. If there is local failure of one column, the load is transmitted to intact supporting columns. This is part of the alleged initial initiation.

But when do free fall and impact and shock wave and overload of the structure below take place? The second initiation. When enough local failures have taken place?

These failures must take place just above the so called impact zone. Any evidence for that?

And all the failed parts must be removed to allow free fall! Any evidence for that?

And an impact must evidently be between really solid parts that can really resist a load from above, i.e. only the vertical columns. And these parts must be aligned and arranged that the upper part does not slide off at impact. Any evidence for that?

If anything impacts a floor, the floor will really sag (easy to visualize) and either break in one location ... or spring back. But what could impact a floor? Another floor above? According NIST nothing happens then! You need 6 floors impacting one floor ... and then only that floor breaks. Any evidence for that?

And a lose floor cannot destroy 280+ vertical columns below.

I find it strange that many greenhorns still believe in the impact theory when even NIST has abandoned it.

 

[Alferd_Packer]

Snip - a lot of nonsense. . .

Is this one of your designs?

 

[MRC_Hans]

I am serious and Seffen implies that the upper block is rigid during the complete collapse. It is this rigid upper block that drives the gravity collapse via the beta L section on top of the crush zone according Seffen so he can write his mathematical equations (read rubbish). Read Seffens paper. Link is in my paper.

I wonder why a serious university lecturer does a thing like that!

Heiwa

No, he does not imply that the upper block is rigid in the real world. He uses the assumption in his simulation, for simplicity.

Didn't you know that simulations always imply some degree of simplification?

Oh, and in case you forgot: The important thing is how the real buildings behaved.

Hans

 

[MRC_Hans]

We are talking about something with a 4 000 m² base, 47 metres high, volume 190 000 m3 most of which is air. It, if it weighs 33 000 tons, can only apply a uniform vertical pressure of 0.85 bar (or 8.5 ton/m²) on the structure below, which is very small.

It applies a pressure of 33,000 tons. Do you consider that small?
Do you consider 8.5 tons/m² a small pressure? It is around the pressure rating for heavy industrial buildings.

However, all these are statical figures. Of course the building could withstand that. It did for several decades. The problem arose when that weight was shifted out of alignment with the supporting columns and started aquiring kinetic energy.

Actually most of the load is applied on the walls and the core, which are very low stressed initially ...

What do you mean low stressed? They were stressed by the weight of the the upper building (33,000 tons). Yes, in the steady state, when the building was intact, those loads were nicely applied to the supporting structure, and the building stood for decades.

and stressed the same after the load has been shifted down.

Wrong. First of all there was the extra load from the impact, but more importantly, the integrity of the support columns was lost, and the alignment was also lost.

The only 'extra' vertical load is the assumed impact load due to 'free fall', but there is no free fall. So the assumption by various experts of a free fall load is erroneous.

Did the upper part of the building move down or did it not move down? Answer: It moved down. Thus, it gained an kintic energy. An energy that was converted to pressure on the (compromised) lower structure where it impacted. The exact speed at which it moved down and whether that was a complete free fall or not is not too interesting.

Only fits a conspiray theory.

Does it? Please explain just how. How is it that loss of structural integrety due to fire and impact damage cannot cause a progressive collapse, but loss of structural integrety due to planted explosives can? Be specific about the differences.

Re horizontal loads, eg moving air, wind, with uniform density 0.0013 (and unknown mass) it can of course apply a pressure on the side of the structure but no real impact of any kind. Answer is yes.

Heiwa

Thank you. So you agree also that your "wool bale" analogy is false?

Hans

 

[MRC_Hans]

What do you mean with: 'On the contrary, all the columns and floor slabs in the upper block remained more or less interconnected for the first half of the collapse.'

Ahh, an easy one. Refer to my earlier beer-can scenario. When you stomp the beer-can (or the next one if it's too late with the first one) do it so the top part comes down more or less on the bottom part. Now iti s 'telescoped' together. The two "floors" are now together, but still more interconnected. They also weighthe same.

My observations of WTC1 are that most of the upper block disintegrates (telescopes into itself) before any collapse of the lower structure below the initiation zone has even started!

That is not what others observe, but let's, for the sake of discussion, asume it was so: So now you have your 33,000 tons mass "telescoped" into into a more or less solid junkheap. What is it's density now (re. your wool-bale analogy)? Please explain the difference between the effect of an intact, low density structure, and a compressed, high-density 'structure'.

Therefore: 'Thus the upper block moved as a single unit and acted as a single mass of ~ 33,000 tonnes on the structure below.' is wrong. An upper block that disintegrates (telescopes into itself) is not a single unit or mass.

If it did not move as a single unit, please explain where those parts that were not part of a single unit went.

And what would this single unit/mass do then? Impact?

What else should it do? Hover??

Hans

 

[MRC_Hans]

The upper block is 4 000 m² large where the primary load bearing columns occupy 5-6 m² cross area. Same with the lower structure.

If the upper block is supposed to impact the lower structure after alleged free fall, evidently the columns of the upper block must drop straight on the columns on the lower structure ... and not slip off. Otherwise there is no solid, instantaneous impact that can cause a shock wave that shakes the columns below into pieces.

And if they don't do that, what stops it then? And if nothing stops it, what keeps it from crashing all the way down, taking everything in its way with it?

In other words, you have now given yourself the choice of the devil and the deep blue sea:

Either it precisely impacted the lower ends of the severed supports, in which case we have a crushing concentration of force,

or it missed them, in which case there was nothing with the strengh to stop it from accelerating further downwards.

In both cases, progressive collapse will ensue.

Anything else is just ... well dropping a bale of wool on a very solid lower structure. No impact! The upper part misses the relevant structure below.

You have here claimed that the upper part of the structure is equal to a wool bale, whereas the lower is a very solid structure. Please explain the difference in the building structure above and below the plane impact point. If the upper part is a wool bale, why isn't the lower part also a wool bale?

Re peer review. Some of you are my peer reviewers. The other greenhorns I just ignore.

Aha. And how do these "peers" receive your arguments?

Is this the reason you have started writing for kids?

Re floors - they are not primary load bearing structure of any static loads. They just transmit weights on them to the columns.

Correct, and do you know how they do that?

Hans

 

[MRC_Hans]

You are 100% right. If there is local failure of one column, the load is transmitted to intact supporting columns. This is part of the alleged initial initiation.

But when do free fall and impact and shock wave and overload of the structure below take place? The second initiation. When enough local failures have taken place?

In your opinion, what will the upper part of the building do when the structure supporting it fails? Hover?

These failures must take place just above the so called impact zone. Any evidence for that?

Why so-called? Are you a no-planer ??

Why must it take place just there? We have photographic evidence of the perimeter columns being pulled inwards below the impact zone.

And all the failed parts must be removed to allow free fall! Any evidence for that?

Let us assume they were not removed. Let's assume they stayed, but failed (bent, broke, were twisted). What will the building, the 33,000 tons of building they have been supporting then do? Hover??

And an impact must evidently be between really solid parts that can really resist a load from above, i.e. only the vertical columns. And these parts must be aligned and arranged that the upper part does not slide off at impact. Any evidence for that?

Let's suppose the descending (let's not discuss speed, I'm sure you are not claiming it should hover) did not come to rest exactly and securely on the severed and bent support ends. Where did the 33,000 tons of upper building come to rest? What stopped it??

If anything impacts a floor, the floor will really sag (easy to visualize) and either break in one location ... or spring back. But what could impact a floor? Another floor above? According NIST nothing happens then! You need 6 floors impacting one floor ... and then only that floor breaks. Any evidence for that?

Are you claiming that a floor can withstand the pressure from 33,000 tons of building?

And a lose floor cannot destroy 280+ vertical columns below.

Can 33,000 tons of building material?

Hans

 

[MRC_Hans]

Well, let's us just take this one, too, even if you are mostly repeating the same faults:

OK, short description. Gravity is a force of attraction between any two objects. WTC1 consisted of many objects and, when WTC1 was intact and all objects were attached to each other, gravity resulted in compressive stresses in the primary load bearing objects (the columns) that were <30% of the yield stress.

Ehr, or to put it more simply, the weight of the building and the objects in it were supported by by the structural columns, which had appr. 200% safety margin of strenght.

A floor is not a primary load bearing object. It just transmits its weight to the primary load bearing objects.

And it does this by transferring vertical forces anywhere on its surface to vertical forces on the supports.

If you cut a primary load bearing object in one location it cannot transmit any load and the stress in it at the cut becomes zero. If you then cut the same object a bit away, the lose part will evidently fall down. If it is located in the wall, it is likely it drops down to the ground outside the structure.

Yes, but we have no evidence that his happened.

In WTC1 we are told that 280+ primary load bearing objects were simultaneously cut in two locations in an initiation zone ... and disappeared. Fair enough! I do not believe it because it is a crazy idea, but let's assume it anyway.

It is indeed a crazy idea, and the only people I've seen promoting it are the CD proponents.

What did observably happen was that those supports that were not severed by plane impacts (which may well have been taken away as you describe) were bent over a lengh of several floors.

What happens then?

Then, when bent, they are no longer able to support the weight they were designed for.

Well, if the upper block above the initiation zone was then hanging in a crane and slowly lowered down and placed on the lower structure, the lower structure would evidently carry the upper block ... as before.

But there was no crane lowering the upper block!

No, and it didn't hover, either. So since it was neither suspended from a crane not able to hover, in your own words, what exactly did it do?

We are told that it (1) free falls and (2) impacts instantaneously and (3) causes a shock wave in the lower structure, it is overloaded, etc. These are crazy ideas, but must be considered in a serious analysis.

So, in your opinion, bereft of supports, what did the 33,000 tons of upper building do?

The PE must evidently be applied to the structure below, but gravity does not work like that for lose objects!

No, the KE was applied to the building below. If you claim it wasn't, please explain where it went. Be specific.

In order for this upper block with 280+ objects to 'impact' the lower structure and overload it, it must be 100% aligned with all 280+ objects below. And then, if the 280+ objects touches the 280+ objects below, they must not slip off! Remember - each column has been split at two locations and the intermediate part has disappeared. Do you believe that the cross surfaces of the broken parts are identical allowing a perfect fit?

No, I sincerely doubt that. So where did it impact? What else was there to stop it on its path downwards??

Evidently, the upper block was not 100% aligned at (1) with the lower structure and therefore it will miss the lower structure at (2). No impact, no shock wave! And no global collapse due to PE>SE!

No impact? So it just continued downwards?? Please elucidate.

Hans

 

[Heiwa]

1. It applies a pressure of 33,000 tons. Do you consider that small?
Do you consider 8.5 tons/m² a small pressure? It is around the pressure rating for heavy industrial buildings.

2. However, all these are statical figures. Of course the building could withstand that. It did for several decades. The problem arose when that weight was shifted out of alignment with the supporting columns and started aquiring kinetic energy.

3.What do you mean low stressed? They were stressed by the weight of the the upper building (33,000 tons). Yes, in the steady state, when the building was intact, those loads were nicely applied to the supporting structure, and the building stood for decades.

4. Wrong. First of all there was the extra load from the impact, but more importantly, the integrity of the support columns was lost, and the alignment was also lost.

5. Did the upper part of the building move down or did it not move down? Answer: It moved down. Thus, it gained an kintic energy. An energy that was converted to pressure on the (compromised) lower structure where it impacted. The exact speed at which it moved down and whether that was a complete free fall or not is not too interesting.



6. Does it? Please explain just how. How is it that loss of structural integrety due to fire and impact damage cannot cause a progressive collapse, but loss of structural integrety due to planted explosives can? Be specific about the differences.

Thank you. So you agree also that your "wool bale" analogy is false?

Hans

1. The 33 000 tons are carried by 280+ columns. Average 118 tons/column

2. So 33 000 tons were shifted out of alignment with the columns below! Good. Actually 118 tons per column was shifted out of alignment. It means that these 118 tons will never again be applied on any column below! And it is valid for all columns.

3. <30% yield. Good industry standard!

4. ?? How can a column below be impacted when the load above has shifted out of alignment?

5. The upper part disintegrates before anything happens below the 'impact' zone. Very visible for WTC1! But see 4. How can a mass above impact a column below if it is not aligned?

6. See above. The beauty of a multi-column steel structure is that, if for any reason a mass above gets lose and starts to drop, it will not be aligned with the structure below = no global collapse. The weight drops beside the primary structure below!

The wool bale analogy I only use when 'experts' talk about uniform density above and other nonsense. The weight of the wool bale is evidently transmitted to 280+ columns as packing ... but when the packing has shifted out of alignment with any support below ... the weight above drops like a bale of wool. Then the stresses in the packing is ZERO. And the wool will just drop by the solid structure below.

Heiwa

PS Above replies all questions in your other comments. Just note that the initiation/impact zone is where the upper part allegedly free falls and vertically impacts the lower structure. Has nothing to do with a plane impacting same area 45-100 minutes earlier horizontally (another thread) which did not cause any global collapse of the intact structure below.

 

[CHF]

Heiwa,

where has your work been published or reviewed?

Just curious.

 

[Alferd_Packer]

2. So 33 000 tons were shifted out of alignment with the columns below! Good. Actually 118 tons per column was shifted out of alignment. It means that these 118 tons will never again be applied on any column below! And it is valid for all columns.

So, it the 33,000 ton mass was no longer being supported by the columns, what was supporting it then?

 

[Dave Rogers]

2. So 33 000 tons were shifted out of alignment with the columns below! Good. Actually 118 tons per column was shifted out of alignment. It means that these 118 tons will never again be applied on any column below! And it is valid for all columns.

[...]

6. See above. The beauty of a multi-column steel structure is that, if for any reason a mass above gets lose and starts to drop, it will not be aligned with the structure below = no global collapse. The weight drops beside the primary structure below!

It's always entertaining to watch the process by which unsupportable assertions descend into total, utter, unarguable lunacy. Heiwa, what you're suggesting is that the upper block should have shifted sideways so that none of the columns were aligned, but remained upright. It should then have fallen till the columns impacted the floors, then... what?

I think we have to go to multiple choice here.

Did the floors (a) suddenly acquire the ability to support the 30,000 ton weight of the upper block, or (b) collapse?

Choose (a) and you're clearly insane. Let's assume (b).

Now, even if the upper block shifted sideways, it must have rested on the lower block at two specific points, where the perimeter columns crossed each other.



This must have concentrated the entire weight of the upper block on two column trees of the perimeter structure. Did these column trees either (a) suddenly increase in strength by over 20 times and support the upper block all by themselves, or (b) fail under the additional load?

Again, choose (a) and you're clearly insane. Choose (b) and suddenly the perimeter column structure is starting to collapse.

Of course, none of this actually happened, because the upper block actually tilted as it fell, giving the additional result that oblique impacts occurred between formerly vertical columns. However, even if we imagine that the upper block miraculously just shifted a small amount sideways and stayed upright throughout the collapse, it's still geometrically impossible for all the columns to have missed each other, and this is obvious to anyone with a kindergarten level understanding of geometry.

Heiwa's explanations are getting more insane with every post.

Dave

 

[DGM]

Heiwa's explanations are getting more insane with every post.

Dave

Now that's saying something considering where he started. He's always assumed that the columns from the upper block landed on the lower in perfect alignment and simultaneously.