WTC7 and the girder walk-off between column 79 and 44

[Justin39640]

Originally Posted by Tony Szamboti

The perimeter columns did have a factor of safety against gravity of 5.00 to 1.

You apparently are not paying attention, as what I claimed was still a static load was the load redistributed onto the east and west perimeter walls after the aircraft impact and alleged south wall failure. Pgimeno was talking about dynamic loads before the fall and I corrected him/her.

My point is that NIST does not show the loading required to cause failure of the east and west walls which would then allow the upper section to fall. NIST stops at the alleged south wall failure and Bazant picks up after the upper section is falling. What needed to happen in between was for the core and east and west perimeter walls to fail to allow the drop.

Bazant's analysis also has problems with his stiffness value for the columns and his upper section mass, besides the fact that there could not have been any dynamic load without a deceleration. No deceleration is observed in the fall of the North Tower. The South Tower isn't really measureable that way.

Your "missing" jolts were the things that made it accelerate at less than FFA.

[Tony Szamboti]

Originally Posted by Justin39640

Your "missing" jolts were the things that made it accelerate at less than FFA.

The less than FFA is not a deceleration. You should learn the difference before commenting.

[Justin39640]

Originally Posted by Tony Szamboti

The less than FFA is not a deceleration. You should learn the difference before commenting.

The increasing falling mass might have something to do with that. You seem to think very one dimensionally I noticed.

[triforcharity]

Originally Posted by Tony Szamboti

Flexing would not cause the SFRM to dislodge on all of the trusses on the complete other side of the building and the central core and several floors above the impact. The SFRM had an adhesive bond strength of somewhere around 2 to 2.5 psi. That is actually pretty strong for light airy stuff. Most industrial strength tapes only have an adhesive bond strength of about 4 to 5 psi.

While correct, there is known problems with the SFRM adhesion, dating as far back as April of 1992. If not applied correctly, with a clean substrate (rust and oil free) it was susceptible to flaking.

So, we know that there were problems with the SFRM application, so the 2-2.5 PSI, while correct, can and will vary if not applied correctly.

http://media.corporate-ir.net/media_...st-public2.htm (under the heading Roger Morse) Also, there are plenty of pictures available. Here's one.

[pgimeno]

Originally Posted by Tony Szamboti

With the answer you are giving here you shouldn't be patting yourself on the back, because you are wrong.

The additional loading is not an average, it is the maximum on any of the columns.

That's not a significant change for my argumentation. The stress on the east and west walls after the south wall buckled was still largely asymmetrical.

[BasqueArch]

Originally Posted by Tony Szamboti

The perimeter columns did have a factor of safety against gravity of 5.00 to 1.

You apparently are not paying attention, as what I claimed was still a static load was the load redistributed onto the east and west perimeter walls after the aircraft impact and alleged south wall failure. Pgimeno was talking about dynamic loads before the fall and I corrected him/her.

My point is that NIST does not show the loading required to cause failure of the east and west walls which would then allow the upper section to fall. NIST stops at the alleged south wall failure and Bazant picks up after the upper section is falling. What needed to happen in between was for the core and east and west perimeter walls to fail to allow the drop.

Bazant's analysis also has problems with his stiffness value for the columns and his upper section mass, besides the fact that there could not have been any dynamic load without a deceleration. No deceleration is observed in the fall of the North Tower. The South Tower isn't really measureable that way.

That's a relief. I thought for a moment that you still believed that the top structure first falling 12 feet onto the floor below generated a static load or that all the columns hit axially and simultaneously onto all the columns below.

[MileHighMadness]

Originally Posted by Tony Szamboti

The girder was expanding towards the columns when it would have broken the bolts and when they break it would tend to move towards the columns and onto the seats at columns 44 and 79 even more due to the restraint being removed.

If the bolts between the girder and the seat are broken by the beam expansion the girder would just be moved the amount it had previously been restrained by the bolts. It can't move further as it is restrained by the beams, and it has been proven that the beams could not expand enough to push the girder off its seat at column 79 and it is restrained by the column flange at column 44.

The column isn’t going to restrain anything. When this connection fails, all bets are off. The large force (energy) released when these bolts fail will push the end of the girder anywhere it wants to go. The girder will probably rip thru structural steel plates of the column with ease. And if you really look that the bottom bolted connection, the bolts probably will not fail first, the bolts will probably rip thru the bottom girder flange and part of the web plate. You will not have to worry about the girder walking off the column, because the bottom of the girder supported by the column bearing plate will be completely GONE.

[BasqueArch]

Originally Posted by Tony Szamboti

..........

My point is that NIST does not show the loading required to cause failure of the east and west walls which would then allow the upper section to fall. NIST stops at the alleged south wall failure and Bazant picks up after the upper section is falling. What needed to happen in between was for the core and east and west perimeter walls to fail to allow the drop.

Bazant's analysis also has problems with his stiffness value for the columns and his upper section mass, besides the fact that there could not have been any dynamic load without a deceleration. No deceleration is observed in the fall of the North Tower. The South Tower isn't really measureable that way.

Quote:

My point is that NIST does not show the loading required to cause failure of the east and west walls which would then allow the upper section to fall.

I already mentioned the force that caused this sequential failure of all the columns. Bazant describes it in detail as a rotating moment which causes column shearing, even has a sketch showing it. Video of South tower collapse shows this, the top section rotating past the still bottom section.

Sequential failure from center columns of south wall (simultaneous with the collapse of the attached center columns hat trusses and their attached core columns) to the sides to east and west walls up to the north wall. Calculated the shear angle at about 2.8 deg. I would think this is a useful concept for an engineer to learn.

Re Bazant stiffness and mass comment, the revised force numbers would still be an order of magnitude greater than the design load.

Your deceleration claim is false and for those unfamiliar, this was throughly proven a conceptual and mathematical failure in another thread. A zombie now, resurrected to persuade the unwary.

The south columns bowed gradually and increasingly over a period of ~ 20 minutes, something that explosives can't produce. The columns lost floor bracing over about 5 floors (the sagging floors). The columns were hot and lost strength, buckled, no longer 5.00 FOS , you neglected to mention this. Also the perimeter columns bowed at the 35 foot wall ends where there were no columns. Core columns would have had to drop ~ 23 feet to produce the 54" bowing, impossible.

The fires and damage explanation is the concensus of all the reputable engineers before and after NIST. It is an integerated explanation and can well explain these collapses, not ad hoc explosives or thermite.

[ozeco41]

I've been watching this latest round of Tony nonsense posting since I listed the six main bits of trickery he persists in employing. (See this post.)

We can now add 'misquoting NIST' to the list of tricks. And, yet again, it is hard to tell whether Tony simply does not understand OR he understands and is being loose with truth in order to mislead people.

As usual we see a mix of incompatible objectives - in the following post confusion between 'NIST wuz wrong!' and 'Explain something about the collapse!' (And recent posts have also included 'Misapply Bazant!' which is the third leg of the usual triumvirate of confused objectives and the errors that flow from mixing up bits of different scenarios. )

I rarely bother checking Tony on details because he persists in making overriding errors in the bigger picture. However I will make an exception on this occasion. Take this:

Originally Posted by Tony Szamboti

NCSTAR 1-6 page 300 to 304 shows the additional loads put on the east and west walls after impact were about 7% more than their original load and 30 to 35% more on top of that after the alleged south wall failure.

These columns had a 5.00 to 1 factor of safety against gravity. So they were originally only loaded to 20% of their capacity. The NIST after impact and after south wall failure loads would then be

20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.

The NIST report does not make a case for failure of the east and west perimeter walls. Unfortunately, this just sails right over the heads of most.

OK I will limit myself to making two points about this parody of reasoning:
1) "20% x 1.07 x 1.35 = 29%." Well that is not what NIST said. Go check the source doc from this link. (It is also under the spoiler which follows - look at the bits I have emphasised with italic, bold and Larger Font.) (CLUE the key word is 'respectively' )

BUT that first point is the minor error - and it goes against the argument Tony was trying to make ;

This is the big deception:
2) Read NIST - the relevant bit is under the spoiler - it is clearly discussing progress of a cascading failure - a dynamic process. Tony has been avoiding the reality of 'cascading failure' for all of this off topic derail and he is currently seeking to misrepresent the cascade process which is under way as 'static'.

...Note: I have highlited some of the bits which say 'dynamic'. The italic, bold italic large font parts reveal the error or deliberate deception referred to under my point '1)':

Originally Posted by NIST NCSTAR 1-6

Buckling of South Wall and Collapse Initiation
The inward bowing of the south wall increased as the post-buckling strength of bowed columns continued to reduce. The bowed columns increased the loads on the unbuckled columns on the south wall by shear transfer through the spandrels. Consequently, instability progressed horizontally, and when it engulfed the entire south wall, it progressed along the east and west walls. Moreover, the unloading of the south wall resulted in further redistribution of gravity loads on the south wall to the east and west walls and to the thermally weakened core via the hat truss. At 100 min, the north, east, and west walls at Floor 98 carried about 7 percent, 35 percent, and 30 percent more gravity loads than the state after impact, and the south wall and the core carried about 7 percent and 20 percent less loads, respectively. The increased loads on the east and west walls were due to their relative higher stiffness compared to the impact
damaged north wall and bowed south wall. The section of the building above the impact zone began tilting to the south at least about 8 ̊ as column instability progressed rapidly from the south wall along the adjacent east and west walls, as shown in Fig. 9–13. The gravity loads could no longer be redistributed, nor could the remaining core and perimeter columns support the gravity loads from the floors above. The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could have been absorbed by the structure. Global collapse ensued.

So with those two bits of confusion or deliberate trickery out of the way (only those two - leave the rest for later ) ...let's look at what pgimeno said:

Originally Posted by pgimeno

But... Tony...

I am not an engineer, yet even I can see how the average load on a wall is not necessarily the same as the load on an individual column, and that the stress on the east and west walls after the south wall buckled was largely asymmetrical. I know that wishful thinking is powerful, but one would assume that given your profession you would be above that and not make such an obvious mistake.

...anyone disagree with my opinion that all of pgimeno's claims in that quoted post are true?

Here is my reasoning for each point pgimeno made in his post:
'I am not an engineer,..' I believe him.
'...yet even I can see how the average load on a wall is not necessarily the same as the load on an individual column,...' True in at least two ways. First I accept that such is pgimeno's perception AND second the reality was that loads were dynamically redistributing - as a consequence of that dynamic process the next point:
' and that the stress on the east and west walls after the south wall buckled was largely asymmetrical.' ...is true. It is an issue of engineering understanding which I have addressed or alluded to many times - reallocation of loads depending on spatial arrangement of surviving columns PLUS the progressive nature of a cascade failure. Tony has wrongly rejected those fundamental issues of engineering fact.
'I know that wishful thinking is powerful,...' I agree;
'...but one would assume that given your profession you would be above that...'...it must be a truism that a professional should be capable of objective analysis AND
'...and not make such an obvious mistake.' Correct - it is another aspect of 'professionalism' - not making elementary mistakes.

Originally Posted by Tony Szamboti

With the answer you are giving here you shouldn't be patting yourself on the back, because you are wrong....

No he isn't wrong Tony. And even if he has a couple of 'shades of grey' not quite right nuances he is way ahead of your false claims and wrong explanations. And he isn't an engineer. And there is no suggestion that he is trying to mislead others.


PS Apologies to pgimeno, BasqueArch and MileHighMadness - I took a while to type this and posted it before I realised you three had posted - I don't think it conflicts with your posts.

I must learn to check for updates before posting.

[Tony Szamboti]

Originally Posted by pgimeno

That's not a significant change for my argumentation. The stress on the east and west walls after the south wall buckled was still largely asymmetrical.

The additional loading on any of the columns in the east and west perimeter walls was nowhere near enough to cause those columns to fail. This is a problem for the NIST analysis.

[Tony Szamboti]

Originally Posted by Justin39640

The increasing falling mass might have something to do with that. You seem to think very one dimensionally I noticed.

There is a problem with the fact that there was no deceleration observed from the beginning of the fall. For a dynamic load to occur there has to be deceleration. This means velocity loss. There was never any velocity loss.

In the measurements of the North Tower it appears that about 90% of the structural integrity is being removed and the structure is just falling through the small amount of structure remaining which cannot handle the static load.

[Tony Szamboti]

Originally Posted by BasqueArch

I already mentioned the force that caused this sequential failure of all the columns. Bazant describes it in detail as a rotating moment which causes column shearing, even has a sketch showing it. Video of South tower collapse shows this, the top section rotating past the still bottom section.

Sequential failure from center columns of south wall (simultaneous with the collapse of the attached center columns hat trusses and their attached core columns) to the sides to east and west walls up to the north wall. Calculated the shear angle at about 2.8 deg. I would think this is a useful concept for an engineer to learn.

Re Bazant stiffness and mass comment, the revised force numbers would still be an order of magnitude greater than the design load.

Your deceleration claim is false and for those unfamiliar, this was throughly proven a conceptual and mathematical failure in another thread. A zombie now, resurrected to persuade the unwary.

The south columns bowed gradually and increasingly over a period of ~ 20 minutes, something that explosives can't produce. The columns lost floor bracing over about 5 floors (the sagging floors). The columns were hot and lost strength, buckled, no longer 5.00 FOS , you neglected to mention this. Also the perimeter columns bowed at the 35 foot wall ends where there were no columns. Core columns would have had to drop ~ 23 feet to produce the 54" bowing, impossible.

The fires and damage explanation is the concensus of all the reputable engineers before and after NIST. It is an integerated explanation and can well explain these collapses, not ad hoc explosives or thermite.

The lack of deceleration issue was not proven a conceptual and mathematical failure in any way shape or form.

The North Tower falls straight down for the first couple of stories and only begins rotating after that initial amount of fall, so the tilt/rotating issue is shown to be irrelevant there. It is interesting that the propagation across the North Tower at the 98th floor occurred in just 0.7 seconds and that the upper section comes down somewhat evenly for the first couple of stories. The North Tower is the more illuminating study.

The perimeter columns did not get very hot as they were being cooled by outside air. NIST only found three spots where the temperatures were above 250 degrees C out of their check of 236 pieces of steel. Steel hasn't lost any strength at 250 degrees C.

[Robrob]

Originally Posted by Tony Szamboti

The perimeter columns did not get very hot as they were being cooled by outside air. NIST only found three spots where the temperatures were above 250 degrees C out of their check of 236 pieces of steel. Steel hasn't lost any strength at 250 degrees C.

The beauty of CT. One half argues there were molten pools of steel dripping down the building, the other half argues the steel didn't get warm at all. It seems the only thing CT can agree on is there was a conspiracy.

[GlennB]

Originally Posted by Tony Szamboti

There is a problem with the fact that there was no deceleration observed from the beginning of the fall. For a dynamic load to occur there has to be deceleration. This means velocity loss. There was never any velocity loss.

"There was no velocity loss as measured intermittently at a point on the roofline" is what you really meant to type, of course.

You're welcome.

eta: Way back in time in the "Missing jolt" thread you agreed to provide a wee diagram to illustrate how columns could fail and still have their ends meet axially. Any progress with that?

[BasqueArch]

Originally Posted by Tony Szamboti

The lack of deceleration issue was not proven a conceptual and mathematical failure in any way shape or form.

The North Tower falls straight down for the first couple of stories and only begins rotating after that initial amount of fall, so the tilt/rotating issue is shown to be irrelevant there. It is interesting that the propagation across the North Tower at the 98th floor occurred in just 0.7 seconds and that the upper section comes down somewhat evenly for the first couple of stories. The North Tower is the more illuminating study.

The perimeter columns did not get very hot as they were being cooled by outside air. NIST only found three spots where the temperatures were above 250 degrees C out of their check of 236 pieces of steel. Steel hasn't lost any strength at 250 degrees C.

For the “one powerful jolt” to occur it requires that the ¼” thick column ends meet axially and simultaneously (Bazant) after a 12 foot drop. TS acknowledges that “the propagation across the North Tower at the 98th floor occurred in just 0.7 seconds.” 0.7 seconds (succeeding) is not 0.0 seconds (simultaneously), therefore no “powerful jolt” is expected.

This accepted error is an example of the Tammy Wynette Effect (TWE) – “Stand By Your Fail”, where a subjective belief that pleases one is obstinately sustained over the objective error demonstrated. Rather than admit being wrong, “The Missing Jolt” remains uncorrected or withdrawn, a prion infecting the unaware.

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[Tony Szamboti]

Originally Posted by MileHighMadness

The column isn’t going to restrain anything. When this connection fails, all bets are off. The large force (energy) released when these bolts fail will push the end of the girder anywhere it wants to go. The girder will probably rip thru structural steel plates of the column with ease. And if you really look that the bottom bolted connection, the bolts probably will not fail first, the bolts will probably rip thru the bottom girder flange and part of the web plate. You will not have to worry about the girder walking off the column, because the bottom of the girder supported by the column bearing plate will be completely GONE.

After looking at a sudden release of strain energy as a possibility for the girder falling from its seat, in a rudimentary way, like you have, I don't believe it is possible.

I am aware that the flange of the girder would be torn first before the bolts shear, as the ASTM A572 girder has lower yield strength than the A325 bolts. The clearance holes in the girder would have elongated. However, that would lessen the release of strain energy when the bolts do shear, not the other way around.

You really need to put some values and figures together to show what you are saying is possible.

[Tony Szamboti]

Originally Posted by BasqueArch

For the “one powerful jolt” to occur it requires that the ¼” thick column ends meet axially and simultaneously (Bazant) after a 12 foot drop. TS acknowledges that “the propagation across the North Tower at the 98th floor occurred in just 0.7 seconds.” 0.7 seconds (succeeding) is not 0.0 seconds (simultaneously), therefore no “powerful jolt” is expected.

The 0.7 seconds was the time for the horizontal propagation across the building from south to north.

A jolt would not require the ends of the columns to be aligned so well that the plates they were made up of were matched up perfectly. In a natural collapse the columns would fold during buckling of the first story to fail and you would get bent ends contacting each other in an impact after the fall through that story, with an attendant velocity loss. However, there is no velocity loss observed at any time during the fall of the North Tower.

You seem to be saying the jolts would have been time phased. If that were true we should still see a jolt on the north face, at least on its sides away from the impact zone. We don't see any velocity loss at all.

[Tony Szamboti]

Originally Posted by Robrob

The beauty of CT. One half argues there were molten pools of steel dripping down the building, the other half argues the steel didn't get warm at all. It seems the only thing CT can agree on is there was a conspiracy.

You don't think too deeply do you?

There was very little steel actually saved from the towers and none from WTC 7 for investigators. It is quite possible that it wasn't saved because the actual temperatures experienced by some of those pieces far exceeded what fire could generate, and that would have been a clue as to what caused the collapses.

The point about not finding any steel with high temperatures, on what little steel they did get, is that the investigations can't provide a mechanism for failure with that issue.

[Gamolon]

Originally Posted by Tony Szamboti

NCSTAR 1-6 page 300 to 304 shows the additional loads put on the east and west walls after impact were about 7% more than their original load and 30 to 35% more on top of that after the alleged south wall failure.

These columns had a 5.00 to 1 factor of safety against gravity. So they were originally only loaded to 20% of their capacity. The NIST after impact and after south wall failure loads would then be

20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.

The NIST report does not make a case for failure of the east and west perimeter walls. Unfortunately, this just sails right over the heads of most.

Tony, your numbers from another thread/forum.

Quote:

Using Gregory Urich's mass analysis for the 98th floor perimeter columns, their wall thickness would have been .289". The yield strength at this location was at least 65,000 psi, so a 14 inch box column with about a 16 square inch cross section could handle about 200,000 lbs. with a 5 to 1 safety factor. Given this for 59 columns, each perimeter wall could support about 12 million lbs. with a 5 to 1 safety factor or 48 million lbs. counting all four perimeter walls. The total weight of the upper section of WTC 1, from the 98th floor up, was about 69 million lbs. and the core took about 42% of that load leaving about 40 million lbs. for the perimeter to support.

You say each perimeter wall at that level was able to support 12,000,000 lbs. That was based on 59 columns x 200,000 lbs. If I remove 33 columns due to them being severed by the plane impact, that gives us 5,200,000 lbs. able to be supported by the perimeter wall. According to you, 10,000,000 lbs. was applied to each wall.

Please explain how I am misunderstanding that 10,000,000 lbs. > 5,200,00 lbs. and that this would not be a problem.

Or...

Another way to think about it. Tony claims that the perimeter walls could support 12,000,000 lbs. each with a factor of safety of 5 to 1. 33 columns of one wall were severed by the plane impact reducing the amount able to be supported by that perimeter wall by 53% or 6,360,000 lbs.

The weight of the "98th floor and above" section didn't change load-wise did it? That 6,360,000 lbs had to redistribute somewhere right? It couldn't have just vanished...

Using Tony's logic, that 6,360,000 lbs. was redistributed to the remaining 3 walls. The remaining three walls were already holding up 10,000,000 lbs. according to Tony's calculations. Now was have to add another 2,120,000 lbs. to the remaining 3 walls. That puts us at 12,120,000 lbs. per perimeter wall.

UH OH!

Remember, Tony said that the perimeter walls, WITH a factor of safety of 5 to 1, could support up to 12,000,000 lbs. each.

12,120,000 > 12,000,000 isn't it? Doesn't that mean failure?

How come when I use your own numbers, I can show failure?

[Tony Szamboti]

Originally Posted by Gamolon

Tony, your numbers from another thread/forum.




You say each perimeter wall at that level was able to support 12,000,000 lbs. That was based on 59 columns x 200,000 lbs. If I remove 33 columns due to them being severed by the plane impact, that gives us 5,200,000 lbs. able to be supported by the perimeter wall. According to you, 10,000,000 lbs. was applied to each wall.

Please explain how I am misunderstanding that 10,000,000 lbs. > 5,200,00 lbs. and that this would not be a problem.

Or...

Another way to think about it. Tony claims that the perimeter walls could support 12,000,000 lbs. each with a factor of safety of 5 to 1. 33 columns of one wall were severed by the plane impact reducing the amount able to be supported by that perimeter wall by 53% or 6,360,000 lbs.

The weight of the "98th floor and above" section didn't change load-wise did it? That 6,360,000 lbs had to redistribute somewhere right? It couldn't have just vanished...

Using Tony's logic, that 6,360,000 lbs. was redistributed to the remaining 3 walls. The remaining three walls were already holding up 10,000,000 lbs. according to Tony's calculations. Now was have to add another 2,120,000 lbs. to the remaining 3 walls. That puts us at 12,120,000 lbs. per perimeter wall.

UH OH!

Remember, Tony said that the perimeter walls, WITH a factor of safety of 5 to 1, could support up to 12,000,000 lbs. each.

12,120,000 > 12,000,000 isn't it? Doesn't that mean failure?

How come when I use your own numbers, I can show failure?

Okay confused one, the reason you show different results is that you aren't correct in your approach to the problem.

First, with a 16 sq. inch cross section and 65,000 psi yield strength each perimeter column could handle 16 x 65,000 = 1,040,000 lbs. before failure. So each wall could handle 59 x 1,040,000 = 61,360,000 lbs.. The 12 million lb. load was about 20% of the capacity of a wall and you were considering it a yield load.

At the 98th floor the calculation was done for, the perimeter walls were supporting about 10,000,000 lbs. each. If 33 columns are removed from a wall the spandrel beams redistribute the load over the remaining 26 columns and that wall could still handle 26 x 1,040,000 = 27,040,000 lbs.. Thus the wall with the 33 removed columns still stands, just like what we saw the north face of the North Tower do.

I hope this answers your question and relieves your confusion.

[Animal]

Originally Posted by Tony Szamboti

The additional loading on any of the columns in the east and west perimeter walls was nowhere near enough to cause those columns to fail. This is a problem for the NIST analysis.

Too bad the events of the day prove your statement completely false.

[Animal]

Originally Posted by Tony Szamboti

You don't think too deeply do you?

.

More TS projection.

[Gamolon]

Originally Posted by Tony Szanboti in another thread/forum

]Using Gregory Urich's mass analysis for the 98th floor perimeter columns, their wall thickness would have been .289". The yield strength at this location was at least 65,000 psi, so a 14 inch box column with about a 16 square inch cross section could handle about 200,000 lbs. with a 5 to 1 safety factor.

Originally Posted by Tony Szamboti

First, with a 16 sq. inch cross section and 65,000 psi yield strength each perimeter column could handle 16 x 65,000 = 1,040,000 lbs. before failure.

What gives Tony? In the first quote you say a perimeter column cold handle about 200,000 lbs. WITH a 5 to 1 safety factor.

Now you say it can handle 1,040,000 lbs.?

[Animal]

Originally Posted by Gamolon

What gives Tony? In the first quote you say a perimeter column cold handle about 200,000 lbs. WITH a 5 to 1 safety factor.

Now you say it can handle 1,040,000 lbs.?

Like a evangelical that predicts a day the world will end, and when that day passes..........ignores the previous prediction and picks a new date. It is the only way for the religion to continue.

[NoahFence]

Please let it stop. Let the stupidity stop!!!

[GlennB]

Originally Posted by Tony Szamboti

In a natural collapse the columns would fold during buckling of the first story to fail and you would get bent ends contacting each other in an impact after the fall through that story, with an attendant velocity loss. However, there is no velocity loss observed at any time during the fall of the North Tower.

Are we being asked to believe that in a 'natural' collapse the columns would bend and fail in a synchronised and identical fashion?

Apart from anything else there were, on any given floor, a mix of column types, dimensions and joints. In addition, impact damage varied and temperatures varied across the floor area.

[carlitos]

Originally Posted by Tony Szamboti

...

However, there is no velocity loss observed at any time during the fall of the North Tower.

You seem to be saying the jolts would have been time phased. If that were true we should still see a jolt on the north face, at least on its sides away from the impact zone. We don't see any velocity loss at all.

Without getting too mathy, couldn't a bunch of increasing mass headed downwards due to gravity, experience some small "jolts," resulting in reductions in the rate of acceleration, not "velocity loss?" Like a bowling ball through a glass table. Am I having deja vu here?

[Animal]

Originally Posted by NoahFence

Please let it stop. Let the stupidity stop!!!

[BasqueArch]

Originally Posted by Tony Szamboti

The 0.7 seconds was the time for the horizontal propagation across the building from south to north.

A jolt would not require the ends of the columns to be aligned so well that the plates they were made up of were matched up perfectly. In a natural collapse the columns would fold during buckling of the first story to fail and you would get bent ends contacting each other in an impact after the fall through that story, with an attendant velocity loss. However, there is no velocity loss observed at any time during the fall of the North Tower.

You seem to be saying the jolts would have been time phased. If that were true we should still see a jolt on the north face, at least on its sides away from the impact zone. We don't see any velocity loss at all.

For North Tower (Bazant illustration of actual collapse , not the ideal model collapse)

a. South perimeter columns bow.(left side)
b. South perimeter columns fail, core columns sequentially fail, top rotates about CoM toward south wall.
c. Rotation causes column moment, shears all columns sequentially. This is the third time TS has missed Bazant rotation moment= column shear, not compressive failure FOS business. Perhaps some continuing education courses would help this knowledge gap.
d. Rotation continues, all columns shear, top block falls.
e. North wall top falling columns (14” x 14”) completely miss bottom columns. No jolt
North tower : couldn’t find clear east or west video.
See South tower for live example of this rotation past bottom columns [:03 sec]

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Still fail. Got anything else?

[BasqueArch]

Originally Posted by NoahFence

Please let it stop. Let the stupidity stop!!!

Sorry Noah, aliens have absorbed the bodies of, to all appearances, reasoning humans.
Stupidity will continue as long as there's an alien sucker born every minute.

[tsig]

Originally Posted by Tony Szamboti

It is hard to understand how you think the upper section imposed a dynamic load on the east and west perimeter walls after the south wall allegedely failed according to NIST. This is still a static situation because nothing was moving yet. The redistributed loads that NIST shows on the east and west wall columns are nowhere near enough to cause them to fail, so NIST does not explain the propagation of the collapse across the building.

If you believe they do then cite where you believe they do and we can discuss that.

OK Tony, why did WTC7 fall? Now is the time and here is the place for you to tell us why it fell, you've said why you don't believe the official story but you've never said what you think really happened.

[000063]

Originally Posted by Clayton Moore

You and Christopher7 are wasting your time.

These people don't give a crap about the truth....

My irony meter just broke.

Was it us or Chris7 who made assertions about experimental nanothermite bombs that he refuses to discuss?

Was it us or Tony who claimed that buildings are usually designed to hold up to twice their weight, yet never, ever provided evidence?

[ozeco41]

OK Tony's silly game is getting sillier. Everyone remember that I explained some bits of engineering reality for Gamolon's benefit. Advising Gamolon to have fun playing with Tony's nonsense but not forgetting that Tony's claims were nonsense. Gamolon replied:

Originally Posted by Gamolon

Thanks Oz.

I'll never lose sight of the real situation and as you understand, I'm playing in their realm for the moment using Tony's logic, calculations, and numbers....

So let's just dispose of this latest bit of male bovine excreta from Tony:

Originally Posted by Tony Szamboti

Okay confused one, the reason you show different results is that you aren't correct in your approach to the problem.....

Nonsense Tony. He is not confused other than by the choice to work with your nonsense logic and numbers - a choice he has deliberately taken. He is 'playing in [your fantasy] realm for the moment using Tony's logic, calculations, and numbers....' AND he has said that '[he will] never lose sight of the real situation'.

Originally Posted by Tony Szamboti

...First, with a 16 sq. inch cross section and 65,000 psi yield strength each perimeter column could handle 16 x 65,000 = 1,040,000 lbs. before failure. So each wall could handle 59 x 1,040,000 = 61,360,000 lbs.. The 12 million lb. load was about 20% of the capacity of a wall and you were considering it a yield load....

WRONG in three ways (at least).
1) Columns fail in two main ways depending on slenderness - viz 'yield strength' for shorter columns and 'buckling' for longer columns. 'Buckling' occurs at much lower loads than 'yield' and the columns of WTC which are relevant to this discussion failed in buckling - the 'weaker' mode. Gamolon is merely playing within your false setting - you chose 'yield' and it was a wrong choice;
2) The underlying error of 'proportional re-distribution' (implicit in the 59 x 1,040,000 = 61.360,0000.) I have pointed this error out in detail several times and Tony ignores my advice. When Tony ignores advice it is a good sign that he is wrong, that he knows that he is wrong and that the advice is correct. So let me repeat for the umpteenth time when columns are removed the load redistribution is not uniform proportional. It depends on the spatial arrangements of the remaining columns. My sketch is true and relevant - if anyone wants more details ask and I will post said details:

(I note that BasqueArch has posted the Bazant explanation - I won't confuse readers more by critiquing Bazant at this stage. Where 'moment induced shear' - Bazant's emphasis - and 'column buckling' - my current emphasis - fit in the whole picture is more complex than we need to deal with right now. If anyone wants to explore the details I can explain how the two approaches are not in conflict - they are actually valid complementary parts of the overall picture. Tony's errors are at a much more basic level.)

3) Tony says 'and you were considering it a yield load....' as if that was Gamolon's wrong choice. WRONG. It was Tony's wrong choice and Gamolon, as he said, was simply playing within the limits of Tony's nonsense claims.

The next bit of nonsense:

Originally Posted by Tony Szamboti

...At the 98th floor the calculation was done for, the perimeter walls were supporting about 10,000,000 lbs. each. If 33 columns are removed from a wall the spandrel beams redistribute the load over the remaining 26 columns and that wall could still handle 26 x 1,040,000 = 27,040,000 lbs.. Thus the wall with the 33 removed columns still stands, just like what we saw the north face of the North Tower do....

...merely repeats Tony's false premise about uniform redistribution of loads. WRONG - it doesn't work that way and there is no point me explaining yet again why Tony is wrong. However any non-engineer who wants more explanation can simply ask. Try this: Do you comprehend why, as a first approximation and with 33 columns taken out on 'North Face', the load redistribution was as if 33 columns had also been removed on 'South Face'. Sure is counter intuitive isn't it? Look again at my sketches under the spoiler. Note the 0 (zero) load in the left column row of case 2a

Originally Posted by Tony Szamboti

...I hope this answers your question and relieves your confusion.

I doubt that you are serious with that Tony - otherwise you would drop this nonsense of 'uniform proportional re-distribution'. It is pure fantasy.

[tsig]

Originally Posted by Tony Szamboti

After looking at a sudden release of strain energy as a possibility for the girder falling from its seat, in a rudimentary way, like you have, I don't believe it is possible.

I am aware that the flange of the girder would be torn first before the bolts shear, as the ASTM A572 girder has lower yield strength than the A325 bolts. The clearance holes in the girder would have elongated. However, that would lessen the release of strain energy when the bolts do shear, not the other way around.

You really need to put some values and figures together to show what you are saying is possible.

Then what is possible Tony?

You really need to put some values and figures together other than a spread sheet.

[Tony Szamboti]

Originally Posted by Gamolon

What gives Tony? In the first quote you say a perimeter column cold handle about 200,000 lbs. WITH a 5 to 1 safety factor.

Now you say it can handle 1,040,000 lbs.?

This apparently isn't an area you are familiar with. You aren't applying the factor of safety to the load to get the failure load without it.

The 200,000 lbs. is what it has on it WITH a factor of safety of 5 to 1. In other words it could take five times that much with no factor of safety.

Multiply the 200,000 lbs. by 5 and you get 1,000,000 lbs. for the failure load or the load WITHOUT a factor of safety.

I hope this finally clears it up for you.

[Tony Szamboti]

Originally Posted by BasqueArch

For North Tower (Bazant illustration of actual collapse , not the ideal model collapse)
http://www.bollyn.com/public/Bazant_illustration.JPG
a. South perimeter columns bow.(left side)
b. South perimeter columns fail, core columns sequentially fail, top rotates about CoM toward south wall.
c. Rotation causes column moment, shears all columns sequentially. This is the third time TS has missed Bazant rotation moment= column shear, not compressive failure FOS business. Perhaps some continuing education courses would help this knowledge gap.
d. Rotation continues, all columns shear, top block falls.
e. North wall top falling columns (14” x 14”) completely miss bottom columns. No jolt
North tower : couldn’t find clear east or west video.
See South tower for live example of this rotation past bottom columns [:03 sec]

YouTube Video This video is not hosted by the JREF. The JREF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.

I AGREE

Still fail. Got anything else?

The illustration you show is for the South Tower. We are talking about the North Tower and its upper section fell straight down for the first couple of stories and only then tilted, so the tilt/rotation argument does not work to obviate the need for a jolt there.

[tsig]

Originally Posted by Tony Szamboti

This apparently isn't an area you are familiar with. You aren't applying the factor of safety to the load to get the full load without it.

The 200,000 lbs. is what it has on it WITH a factor of safety of 5 to 1. Multiply the 200,000 lbs. by 5 and you get 1,000,000 lbs. for the load WITHOUT a factor of safety.

I hope this finally clears it up for you.

What's the factor of safety of a damaged building?

BTW what did actually happen to the building if not gravity?

[Tony Szamboti]

Originally Posted by tsig

What's the factor of safety of a damaged building?

BTW what did actually happen to the building if not gravity?

No more than 15% of the 283 columns in the North Tower were damaged during impact and the collapse initiated at the 98th floor where less than 1% if even that were damaged.

We can even cut the factor of safety by 20% and there is still way more capacity left to support the load and show a significant deceleration should have occurred in a natural collapse.

The official stories for the collapses have lots of problems because they are fictional.

[Spanx]

Hi Tony
If you look at the approach angles of the planes it explains why both towers did not collapse in the same manner.

Nobody has any idea of the exact condition of the internal core structure after impact and that includes you.

[Tony Szamboti]

Originally Posted by Spanx

Hi Tony
If you look at the approach angles of the planes it explains why both towers did not collapse in the same manner.

Nobody has any idea of the exact condition of the internal core structure after impact and that includes you.

What can be said is that the wings could not have made it to the central core as they would have certainly been broken up completely by the exterior and floors.

That leaves a 16.5 foot diameter fuselage, two five foot diameter turbojet portions of the engines (the fans were not strong enough to survive the exterior impact), and the landing gear. The core was 137 foot long normal to the impact on the North Tower, so by volume alone these things could not take out many core columns even if they went all the way through the building.

If 33 perimeter columns are what were severed on the exterior that is only about 11.5% of the 283 columns and my 15% figure allows for 9 core columns being severed in addition to the 33 on the exterior.