9/11 media happenings

[Jazzz]

NO IT'S NOT! IT'S THE ENTIRE FUCKING POINT!!!!

With respect MikeMcc, it's not the point that TA has been challenging me on for several pages of thread and continues to do so now. Yes, it's an important thing to address and I'll do so, but it will take a decent-sized post to do it, and it will have to wait.

 

[MikeMcc]

And you never answered my question about the 1968 NYC Building Code. But I don't keep repeating it.

You cheeky bastard! As if you haven't avoided questions.

What part of the DCRs involved the DESIGN loads didn't you understand.

 

[Jazzz]

I really can't believe that 4% of ALL of my postings to date have been spent in answering this rubbish!

Hasn't stopped you misinterpreting the DCR ratios - nor has it stopped you failing to comment on the 1968 NYC Building Code - and you seem to imply that the compressive strength for steel is equivocally the same as compressive yield point which I don't believe.

 

[Jazzz]

What part of the DCRs involved the DESIGN loads didn't you understand.

What problem are you having with the DCR figures now? I have no problem with them. You'll have to make yourself a lot clearer if you want me to help you.

 

[MikeMcc]

With respect MikeMcc, it's not the point that TA has been challenging me on for several pages of thread and continues to do so now. Yes, it's an important thing to address and I'll do so, but it will take a decent-sized post to do it, and it will have to wait.

No, no, no, no! It won't wait. You can't distinguish any difference. We know the combined structure was self supporting. TA, and Crispy (I stand to be corrected) don't believe that the core was ever designed to stand as a structure on it's own, a point, IMO that you have contended. Pre impact the structural integrity can be ignored

What the structure did, or was able to do has very litttle bearing on the behaviour of the structures post impact because the base conditions changed massively. There was substantial loss of integrity of the perimeter structure immediately on impact (in the impact zone and in all of areas affected by the path of the engines, undercarriage, etc). There was damage of up to 30% of the load bearing capacity of the core immediately on impact. There was a substantial fire that was reported able to seriously reduce the compressive strength ot the structural steelwork, leading to the tilt and collapse of the upper structures, the impact caused masiive impulses to weaken the lower structures and facilitate the pancake collapse of the core and the floors and the peeling of the perimter structure. It's not a difficult idea, it's logical and it's simple. What EVIDENCE have you got to say that this is untrue.

To consider CD we have the evidence that NO ONE saw anything at the roughly 5000 locations that would be necessary to demolish the structure (assuming a linear scaling from the building that I used in the CDI link before). To consider the idea of 'dustification' then you have to think of the engergies involved in vapourising steel, and that this power would have to be located in a satellite, to my knowledge, these engergies could only result from an x-ray lazer and (as far as I am aware nobody set off an LEO nuke that day. No one has proved any aliens as far as I am aware. any other woo-woo ideas you want shot down?

 

[MikeMcc]

What problem are you having with the DCR figures now? I have no problem with them. You'll have to make yourself a lot clearer if you want me to help you.

Right, so you admit TA's arguement then that the capacity over above the design loading is likely to be in the order of 40% (IIRC) and not able to withstand the 6400% that it actually received.

Can you give me the link to the NYC codes that you are so fond of quoting? I've got the general one for the document, but life is too short to go wading though all of the document since you can't globally search it. I would happily like to look at it and reply to your question, which is more than can be said about you.

 

[MikeMcc]

What problem are you having with the DCR figures now? I have no problem with them. You'll have to make yourself a lot clearer if you want me to help you.

You help me! That's a laugh! The only help you can give me is to provide the link about the NYC 68 codes to save me the trouble of wading through everything. That way I'll be able to answer your question faster.

 

[Jazzz]

No, no, no, no! It won't wait. You can't distinguish any difference. We know the combined structure was self supporting. TA, and Crispy (I stand to be corrected) don't believe that the core was ever designed to stand as a structure on it's own, a point, IMO that you have contended. Pre impact the structural integrity can be ignored

There's a lot going on. I made the point that the core could stand on its own - I was the one attacked for that. So I proved it could. Crispy has since conceded somewhat over that one.

The original post where I quoted the 1968 NYC Building Code load requirements is here - post #1123

.. as I understand it, those requirements demand a core redundancy of 250% albeit with deformations.

 

[Jazzz]

Right, so you admit TA's arguement then that the capacity over above the design loading is likely to be in the order of 40% (IIRC) and not able to withstand the 6400% that it actually received.

You are confused. I've corrected TA repeatedly over his erroneous understanding that the DCR represents the safety factor. So your first bit, no I admit nothing of the sort. The second, I have talked about earlier and will do so again tomorrow, unless I am still having to explain DCR ratios.

 

[MikeMcc]

From what I can see from that requirement is that at any point in the structure it should be designed to support 150% of load at that point due to the mass of the assemblies attached to it OR 100% of the mass of the attached assemblies + 250 % of the design live load (minimal for the core) and dead load (the % shared load of the elevators, plumbing and electrics in the cores + half the floor truss mass and half the dead load on the floor), whichever is greater. The test loads to be able to be left in place for one week to prove that point in the structure.

How does that mean anything to the 6400% loading when the building collapsed?

 

[MikeMcc]

..and you seem to imply that the compressive strength for steel is equivocally the same as compressive yield point which I don't believe.

Feel free, it's in the text books. The one I quoted was dated 2002 so I suppose he must have been in the plot to re-write engineering physics to suit the arguement too.

 

[Jazzz]

From what I can see from that requirement is that at any point in the structure it should be designed to support 150% of load at that point due to the mass of the assemblies attached to it OR 100% of the mass of the attached assemblies + 250 % of the design live load (minimal for the core) and dead load (the % shared load of the elevators, plumbing and electrics in the cores + half the floor truss mass and half the dead load on the floor), whichever is greater. The test loads to be able to be left in place for one week to prove that point in the structure.

How does that mean anything to the 6400% loading when the building collapsed?

Right, that's how I understood it. It means the core has a redundacy of over 250%. It can take 250% of its design dead and live loads without failing. Any problem with that?

 

[editor]

How much longer are you going to keep dishonestly pretending that you've answered my questions, Jazzz?

You're really not fooling anyone you know, and your refusal to come up with a remotely rational explanation about the explosives just proves that your 'theory' is a laughable pile of fact-free loonery.

So how did they invisibly smuggle in these invisible explosives, how were they installed, and in which offices on what what floors were they located?

Oh, and how come not a living soul saw a single thing? Could you give me a single example from anywhere in the world of a large occupied skyscraper being blown up by invisible explosives please?

 

[MikeMcc]

Right, that's how I understood it. It means the core has a redundacy of over 250%. It can take 250% of dead and live loads without failing. Any problem with that?

No it doesn't. Under normal conditions any point is going to have an expected load load of 100% of the structure connected to it an capable of supporting an additional 50%. This is prevalent at points lower in the structure where they are supporting the upper structure. At the very top the codes mean that the dead and live loadings become more important than the the mass of the support structure until, at the very top the dead and live load of the roof stucture become the over-riding factor.

It certainly doesn't mean that the structure as a whole could support 150% of it's own mass and 250% of dead and live loadings. The key phrase in each sub-section is 'that will be added at the site'.

 

[MikeMcc]

Given that I now feel I've answered your question ( I stand to be corrected if I've got it wrong, I'm a motion control engineer, not a structural engineer) will you you now reply to the questions that you have been asked about a plausible plan to CD the towers and where you got the 600% safety margin?

 

[Jazzz]

Feel free, it's in the text books. The one I quoted was dated 2002 so I suppose he must have been in the plot to re-write engineering physics to suit the arguement too.

I confess to being genuinely puzzled over that quote. Not least because of the 1968 design code which demands 250% redundancy, and I am only getting 201% without capacity past yield point. Also, because the steel specifications state (NIST tells us)

"After reaching the yield strength, structural steel components continue to have significant reserve capacity, thus allowing for load redistribution to other components that are still in the elastic range."

... which seems very much to say that the steel components will be able to go beyond the yield strength before failing. And this comment on 'ask a scientist' very much suggests that compressive strength is beyond yield point, although buckling may be a problem in the plastic phase.

 

[editor]

So Jazzz. About these invisibly installed invisible explosives brought in by invisible people....

 

[Jazzz]

No it doesn't. Under normal conditions any point is going to have an expected load load of 100% of the structure connected to it an capable of supporting an additional 50%. This is prevalent at points lower in the structure where they are supporting the upper structure. At the very top the codes mean that the dead and live loadings become more important than the the mass of the support structure until, at the very top the dead and live load of the roof stucture become the over-riding factor.

It certainly doesn't mean that the structure as a whole could support 150% of it's own mass and 250% of dead and live loadings. The key phrase in each sub-section is 'that will be added at the site'.

But the mass of the structure above is 'dead load'. And if each member can support 250% of its design load, then so can the structure, surely. 'that will be added at the site' just refers to the dead load to come, i.e. the columns at the 75th floor are going to have to be able to include the dead load of the 76th and above floor, not just the dead load of its own floor.

There isn't a 'whichever is greater' for the two considerations: one refers to staying within the yield point (no visible damage) whereas the second allows deformation to take place.

 

[editor]

Yoohoo! Jazzz! There's no point you troubling your little head trying to desperately manipulate figures you're woefully unqualified to analyse because unless you can offer a remotely sane explanation as to how the WTC was invisibly wired with invisible explosives, your bonkers theory has no substance at all.

 

[Jazzz]

As you say, editor

 

[editor]

As you say, editor

Why won't you answer my questions, Jazzz? Or are you really too afraid to face the truth?

Other people have already commented on your dishonest and evasive tactics in this thread, so maybe it's time you start acting like an adult here.

If you're unable to come up with a remotely credible explanation and are basing your theory on nothing more than a religious like belief in the impossible, just say so.

 

[MikeMcc]

I confess to being genuinely puzzled over that quote. Not least because of the 1968 design code which demands 250% redundancy, and I am only getting 201% without capacity past yield point. Also, because the steel specifications state (NIST tells us)

"After reaching the yield strength, structural steel components continue to have significant reserve capacity, thus allowing for load redistribution to other components that are still in the elastic range."

... which seems very much to say that the steel components will be able to go beyond the yield strength before failing. And this comment on 'ask a scientist' very much suggests that compressive strength is beyond yield point, although buckling may be a problem in the plastic phase.

Foot...Gun...Bang...again!

Your source says "steel theoretically responds the same way in either tension or compression". The case it gives when it is desireable is during an earthquake when the forces on the structure are generally lower and is used for things like tie-down brackets for machinery in earthquake zones.

Your quote of the regs should have given you a clue as well. If surrounding components are within the elastic range than it doesn't really matter if a single component exceeds the yield point because it can't move anywhere. The codes are specifying abnornal loads applied to a single assembly not to the structure as a whole.

 

[MikeMcc]

But the mass of the structure above is 'dead load'. And if each member can support 250% of its design load, then so can the structure, surely. 'that will be added at the site' just refers to the dead load to come, i.e. the columns at the 75th floor are going to have to be able to include the dead load of the 76th and above floor, not just the dead load of its own floor.

There isn't a 'whichever is greater' for the two considerations: one refers to staying within the yield point (no visible damage) whereas the second allows deformation to take place.

My apologies about the OR statement. The worst case is the second one, it means that that a structural member at the bottom will support at least an additional 50% of its own mass (minimal) + 250% of the dead load (static loadings) + 250% of the live load (essentially the wind loading, which for the core in the WTC is minimal)


So for the bottom of the structure each component is designed to carry its own mass + 50% + 250% of the column above it (+50% of the floors attached to it) above. This balance still changes as you progress up the structure where the mass of the structure above decreases. it also helps explain why part of the lower cores remained standing for a while, they WERE very strong!

It still doesn't change the FACT that it is dealing with one component at a time, rather than the structure as a whole

 

[MikeMcc]

Bloody hell, nearly 6% of all my posts to date now!

 

[Augie March]

I've been reading this thread most of the way through and I have little knowledge on the structual collapse of the building, so I'll leave that to the experts.

But I'm lost on the motive of why exactly the US government would go to all this trouble to commmit such a henious act on their own people.

Jazzz, prehaps an explanation on why they considered it neccessary to launch such an attack on their own country?

 

[MikeMcc]

I've been reading this thread most of the way through and I have little knowledge on the structual collapse of the building.

But I'm just lost on the motive of why exactly the US government would go to all this trouble to commmit such a henious act on their own people.

Jazzz, prehaps an explanation on why they considerd it neccessary to launch such an attack on their own country?

He'll come up with how it's allowed them to implement draconian laws like the Patriot Act and invade Afghanistan and Iraq, supposedly as some pre-ordained Lizard plot to get all the Haliburton profits to fund the Lizard invasion. Cos these things can be all pre-planned.

 

[TheArchitect]

Absolutely amazing. Jazz, you are just wholly unable to read and understand technical details. Example:

The DCRs were calculated by dividing component demands by component capacities, taken at unfactored (working) loads and at working stresses, not at ultimate loads or yield stresses... The component capacities were based on the nominal steel strength as specified in the original design documents..."

So in other words, NIST used the design yields (36ksi) not the test yield results that they did themselves. Then in my calculation I added on the additional safety factor arising from the average actual yield figures.

The only reason that you're banging on about this is because you - and you alone here - think that (a) structures retain integrity above yield point and (b) you think that tensile strength is relevant to compressive (gravity) failures!

The only time we use tensile strength is in considering perp. loadings such as wind where one side of a column is in tension and the other in compression. And that's not applicable in buckling deformation.

But what hope is there of educating someone who made up a load factor of 600% (ie 6.0) but can't actually provide a source at all and sees nothing wrong with that?

And tell me Jazz, even if the core capacity was 600% how would that make the structure strong enough to survive dynamic loads of 6400% (based upon a paper which YOU quoted here)?

 

[detective-boy]

45,000 tonnes of the tower collapsed on to a structure which simply didn't have the capacity to take it.

You know that advert for seatbelts in which the small child in the back seat transforms into an elephant when catapulted forward into the back of mum's head ...

... Well, I was just wondering if anyone had worked out the impact, per square metre or whatever, of the top bit hitting the bottom bit like a piledriver when the damaged section eventually gave way. Would need to know:

1. The weight of the non-impact damaged top bit (say from floor 86 upwards) weighed.

2. The distance between floor 86 and the first non-impact damaged floor on the bottom bit (say floor 78).

3. The speed the top bit would have achieved in free-fall in that distance (and an appropriate assumption as to a reduction in that for the resistance provided by the damaged floors in between)

4. The momentum therefore represented by the top bit by the time it met the bottom bit.

5. The area of the cross section

6. Allowing the calculation of the impact expressed in kilos / tonnes per square metre

7. Allowing that to be compared with the normal design capacity (and other figures, say for the impact of a pile driver driving piles into the ground)

 

[wee cough ed]

Even Hitler encountered problems with a conspiracy to justify invading Poland. A German Coroners Officer refused to release bodies of dead prisoners (to be dressed in Polish uniforms to stage a border incident).

I find the idea that G W Bush would manage a conspiracy without encountering exposure (bearing in mind the liability just below his own nose) highly unlikely.

Inquiry into what happened with the Tower Seven backup genny diesel does merit inquiry.

 

[Jazzz]

Absolutely amazing. Jazz, you are just wholly unable to read and understand technical details. Example:

So in other words, NIST used the design yields (36ksi) not the test yield results that they did themselves. Then in my calculation I added on the additional safety factor arising from the average actual yield figures.

No you are the one that doesn't understand it mate. They have worked back, using the steel strength, to determine a working capacity for each member. This is not the point where it would yield, nor the point where it would yield accounting for variations in yield strength as you think - it is a working maximum for which the member would be considered 'fully loaded' under (as they say) normal working conditions. In some isolated cases they found that members had a DCR>1 under the design load, which would demonstrate minor flaws in the original design, but ones easily accommodated by the factor of safety inherent in the steel strength.