WTC-7 Mysteries FINALLY Solved.

originally posted by: reldra

originally posted by: CALGARIAN
Yes, this was def FINALLY resolved... back in 2001.
The MASSIVE amount of fire debris that crushed the side of the building caused it to collapse.

WHY (or who) would have planted explosives in WTC7? lol.

I had thought the owner of the building made the call, so the building would have been pre-wired for detination.

I imagine there had been multiple different plans like this since the 1993 bombing.

I can't find the videos where either a security head or a designer repeatedly said it would happen again after 1993 and asked for upgrades in security protocols, etc after the1993 bombing, maybe someone can assist in finding that, as I know I saw them.

Well...

What .. IF!!

from cause with the 1993 Bombing attempt , the the High Elite or Officials etc.. , Decided to place a STAND BY for a Future demolition. Control Pull... for the Safety..of saving more Lives and less destruction, as a control demolition to FALL ( Free Fall ) in its Own Foot Print ... just in case.. of an event just as it happend in 911 !

8 years to do it ... and just maybe... Someone knew about it ...


to that sound plausible a Secret Demolition Setup on A Dormant Standby.. in the Major WTC Buildings

yeah a wild theory .. but that what its starting to sound like to me anyhow..

ohh yeah .. I forgot ...

that Old Movie Prediction of Course,

Long Kiss Goodknight 1996

Make you wonder.. right to a T!
www.youtube.com...



www.youtube.com...

Prediction Programming perhaps ..

And what about The Long Gunman ?

6 months Prior of the 911 event

www.youtube.com...


Yes, its a Long Stretch , and grabbing the short straws ..

there a lot of NUTJOBS making the wild n crazy theories

but when the people that were there telling of what they heard and saw
from being there in the event, Firemen, Survivors of the towers.
telling of Hearing and FEELING the Explosions , seeing Squibs , and Cleen up crews seeing Molten Steel
buring for days and No office Debris no bigger then the size of a Office Telephone , and nothing but Dust everywere

www.youtube.com...

I don't think his route for hydrogen forming in the debris heaps by steam would be feasible, concerning the abundance of oxygen in the still enclosed air, that could be replenished easily by the air suction through the underground railway tunnels still leading into the basements filled with steel debris and dust and powdered other stuff.
In my opinion, those temperatures were kept so long by some sort of slow oxidizing carbonizing effect, like in those charcoal pits in SE-Asia etc., where oxygen is allowed in that clay-closed heaps of wooden trunks and branches, like the wooden furniture and separation walls in the WTC.
And any mixture of hydrogen gas with oxygen in the air, from 4 to 74 %, will ignite and/or explode instead of leaking to the debris heap surface as pure hydrogen gas.
The suction effect of the heated air rising out through the hot debris would drive that suction and also suck-in new above ground air at the peripheries of the rising hot air columns.

Anaerobic oxidation of iron by the protons of water, at high temperature, can occur when no oxygen at all is present anymore. It then forms either 1, 3 or 4 hydrogen gas (H2) molecules, and three forms of iron oxides respectively, FeO, Fe2O3 and Fe3O4. If still some fresh oxygen comes available, as in those loosely compacted debris heaps in those 2 basements, mostly additional water (H2O) and those three iron-rust forms are formed, and perhaps traces of hydrogen gas.
His H2 gas proposal could only occur very slowly under pure anaerobic corrosion conditions of steel alloys in completely oxygen-free cold groundwater, existing only deep in the earth.
This reaction route then goes via green rust, Fe(OH)2, to Fe3O4 (magnetite) while slowly emitting H2 into that groundwater.
Any 1000 C hot steel in the debris heap that would have been submerged in lots of firefighting or rain water would have cooled very fast, while that water certainly would not be oxygen-free.

The reaction between f.ex. iron filings and dilute acids however, does result in the forming of copious amounts of hydrogen gas.
There were huge, dilute H2SO4 (sulfuric acid) filled, extra emergency battery banks installed in both towers in two floors that were combined to one while their bottom floors were reinforced to accommodate the extra weight of these huge two floor high battery banks filled with dilute H2SO4. They were meant as back-up electrical energy banks for the amount of computers of Fujitsu Bank and another Bank in the other tower in case of a energy failure. Each of the two planes hit one of those power banks.
And dilute H2SO4 plus hot steel does indeed produce hydrogen gas. A big part of that diluted acid would have ended up somewhere not too deep in the debris heaps, since it came from the impact regions, high up in both towers.
H2 plus the right amount of O2 can form a highly explosive mixture.
When mixed stochiometrically, it forms from two H2O molecules (liquid) → two H2 (gas molecules) at the cathode plus one O2 (gas molecule) at the anode in an electrolysis apparatus.
It is f.ex. stochiometrically formed during electrolysis of a bit of aqua-dest in a test tube held upside down in a bowl of aqua-dest, by a low voltage current flowing between two platinum electrodes, submerged in that slightly salted water, and placed inside that inverted test tube. The gases will then bubble to the top of the test tube, where it will slowly start pushing the water surface downwards when more of it forms.
That way you can collect an amount of explosive H2 and O2 mixture, that will ignite with a distinctive whistling sound, after you take the small glass test tube out and turn it around again and quickly stick a glowing match in the gasses.
When 2 test tubes are placed in the same bowl, each holding one electrode, in one is then produced two times more gas (H2) then in the other (O2).
By the way, this H2/O2 gas mixture was used in the main engine of the Space Shuttles, fed from two compressed fluid-gas tanks, while the huge solid booster rocket operated on a compacted solid ammonium perchlorate mixture.

By the way, there would have been quite a lot of aluminum in the top layers of the debris heaps, and airplane aluminum and Al-cladding from the facades can also produce H2 when coming in contact with bases:
2 Al + 6 H2O + 2 OH`` → 2 Al(OH``)4 + 3 H2
The USGS analyzed the pH of the rain/firefighting water mix in the bathtub under the whole WTC complex after a few days and found it to be strongly caustic. So, yes, Al would also form H2 in that strongly basic environment.

Then Tony Duncan proceeds with his calculations :

To calculate the kinetic energy used in the tower destruction takes a moment, after a simple thought experiment, namely considering the tower would fall at G if there were NO resistance, and if it fell so slowly that it consumed ALL its energy, it wouldn’t fall at all. So we can see that the PROPORTION of the energy used up by the collapse must equate with the proportion of G which the collapse was unable to achieve.
As the collapse acceleration was, by truther calculation, established to be about 70% of the acceleration due to gravity, we’ll use that.

One little addition he doesn't take in account :
That 70 % was calculated by f.ex. David Chandler, only for the first 3 seconds for the trajectory of a point on the top corner that he followed falling.
What happened after that is very difficult to determine, because of the huge dust clouds forming. In a natural collapse which proceeds all the way to the ground, as f.ex. seen in the French Verinage demolition done with hydraulic jacks, where they were removing all vertical column strength in a whole floor half way up, at once, we always notice a deceleration peak in the first 1 to 1.5 seconds already.
For the WTC collapse measurements, we don't see any form of sudden deceleration in those 3 seconds, there is a constant acceleration of 70 % of free fall acceleration due to gravity.
(Bažant et al. write in their 2008 Closure paper, that such deceleration would not be measurable from existing videos, in case of the WTC towers, based on erroneous assumptions for mass, velocity and strength of the columns by them. I come back on that later on, when I review Tony Szamboti's June 2016 rebuttal letter on those assumptions by Bažant et al.)

But Tony Duncan takes that 70 % figure for the whole 14 and 17 seconds lasting 2 collapses.
Without considering at all the increasing deceleration that must have taken place, since he assumes a natural collapse, and in all natural collapses, very quickly, in the first second already, an increasing deceleration takes place.
Not in a demolition, there the goal is to get it down as smoothly and fast as can be. Removing any further obstacles on the way down by further demo-charges.

He goes on, assuming that 70 % of the tower fell inside the basements. Well, when observing the aerial photos from just after the collapses, that seems a gross exaggeration, to say the least.
Then he assumes the steel reached 1,000 degrees Celsius, which is an arbitrary figure he magically assumed, based on some theory that all the steel involved, would first turn to iron sulfide and melted. Yup, nice assumption, but not a shimmer of evidence.
Now don't forget he assumed a far too high overall acceleration first; and that far too much steel ended up in the basements. So, adding all these assumptions up, his formula gives a totally different conclusion than he tries to convince you of.
And then we have all these floor plates absent from the debris heaps, and the massive amount of finely pulverized cement and concrete from the floor decks, which thus do not play any role of importance anymore in his energy calculation.
And we saw the majority of the facade column triplets (Vierendeel triplets) with their 3 welded spandrel plates, end up from close to, to far outside the basement peripheries.
So they also did not play any role in his energy calculation.

Tony Duncan : The energy used up in tower destruction was 30% of 246, or 73.9 tonnes of TNT.
Assuming that 30% of the tower fell outside of the basement, then the energy (Er) available to heat the wreckage base (by elastic energy transfer and crushing) was 0.70 * (246 - 73.9), or 120 tonnes of TNT.
We know that the steel reached at least 1,000 degrees Centigrade because that is the melting point of iron sulfide.
We can therefore calculate the mass (m) of steel that was raised to that temperature.
The specific heat of iron (Fs) is known to be 0.45e6 Joules / tonne / degree Celsius.
The ambient temperature was 20 deg C, so the temperature rise (Tr) was 980 degrees Celsius.

Equation: Er = m * Fs * Tr, so m = Er / Tr * Fs = ( 120 * 4.184e9 ) / 980 * 0.45e6
And so m = 5.02e11 / 4.41e8 = 1,138 tonnes - that is, tonnes of red hot steel at 1,000 degrees Centigrade.

So we can see that there is no need to postulate an extra source of energy, and that the basement wreckage heat is also easily accountable, with the additional corroboration of burning hydrogen at the wreckage surface, and molten iron sulfide at the wreckage base.
And so the underlying 'truther' assumption, that the planes couldn't bring down the towers, is shown to be FALSE, as it is shown by calculation, using the physically-correct values, that the potential energy possessed by the towers numerically accounts for ALL the known consequences, through elastic energy transfer, plastic deformation, and HEAT. These results are EVIDENCE of the event. They have been evident to any REAL scientist or engineer from day 1.

Tony Duncan is avoiding many pitfalls for his calculations. At least, he tried to make some.
There must have been an excessive source of unnatural energy.
Read the three publications of Charles M. Beck I have linked to again and again, the last time a few days ago in this thread. I never saw one jota of fundamental critique on those three, from any aided-collapse opponents.
It was submitted to ASCE Journal of Engineering Mechanics, and show the impossibility of natural WTC towers collapses, all the way down to the ground :

1. Mathematical Models of Progressive Collapse and the Question of How Did the World Trade Centers Perish :
Abstract : arxiv.org... 15 pages, 7 figures
Full text pdf : arxiv.org...
2. Role of Compaction Ratio in the Mathematical Model of Progressive Collapse :
Abstract : arxiv.org... 6 pages, 1 figure
Full text pdf : arxiv.org...
3. Descent curve and the phases of collapse of WTC 7 :
Abstract : arxiv.org... 24 pages, 7 figures
Full text pdf : arxiv.org...

In these two diagrams for WTC-1N and WTC-2S shown below, Beck shows that the resistive forces, initiating the two collapses, came according to his calculations only from failing perimeter (facade) columns, and thus he concludes that the resistive force from the core columns played no role at all, or were of no importance in the initiation event, i.o.w. were absent.
Which leads unavoidably to the question, what event caused all the core columns to play no part in collapse initiation. Inevitably the reader will conclude that explosives are the sole solution :



We have to consider that Beck did know the precise value for the ultimate yield force of the perimeter (facade) columns (PCs), and made sophisticated guesses for the ultimate yield force of the core columns (CCs), and their sum (PCs + CCs). Read his nr 1 article linked above, to see what sophistication he used for his guess for the core columns ultimate yield force.

-- more --

If you are interested in thorough science, you might read the following referenced publications.
If you don't understand the calculations, but understand that these kind of papers are first going through a thorough peers review before being published, you could accept the peers their conceptual knowledge and read the text in between their calculations.

In his case, the peers process was, Gourley thinks, politically motivated by the Journal's editors and he explains extensively in the two other links how he experienced it, so it's worth the time you spend on reading those too.

However, it appears to me that the journal editor rejected Bažant's Closure paper, that countered the two peer reviewers arguments, two times, until the third revision by Bažant was accepted, and that did cost Bažant and the journal JEM a period of one year to get it published :

James Gourley, 2008, A critical review of the Bažant et al. papers on the 9/11 WTC Towers collapses.

Gourley : The Bažant/Greening paper repeated and expanded upon Dr. Bažant’s theory of crush down/crush up collapse progression. This crush down/crush up theory was first developed by Bažant in 2001, and expanded on by Bažant & Zhou in 2002, and Bažant & Verdure in 2007.
I find the crush down/crush up theory completely unbelievable for the reasons I stated in my paper.

An extensive explanation about the hurdles that needed to be taken by the author of the above critical paper on the 2007 JEM paper by Bažant & Greening, to get his critical paper published in 2008 in the same Journal of Engineering Mechanics (JEM) , can be read here : 911blogger.com...
In short, he was held to a 2000 words limit, while Bažant in his reply to him was not, he wrote between 4000 and 6000 words. Bažant kept arguing that Gourley in his critique had not included his calculations. Without mentioning that it was impossible, because of Gourleys 2000 words limit, while he, Bažant, could write as many words as he wanted in his articles for JEM.

Michael Wolsey interviews James Gourley :
www.911blogger.com...
Direct download link and Visibility Webpage :
visibility911.libsyn.com...#

This is the published version of the 2008 Bažant/Le/Greening/Benson paper :
Bažant, Z. P., Le, J.-L., Greening, F. R., and Benson, D. B. (2008).
“Collapse of World Trade Center Towers: What did and did not
cause it?” Structural Engineering Rep. 07–05/C605c, December revision,
Northwestern Univ., Evanston, Ill., also J. Eng. Mech., 134(10),892–906.
2008 Published Bažant et al. paper.


The Gourley critical peer review, that held back the by Bažant and Le written Closure publication for almost a year, was also published in the same JEM journal, in that same final Closure.
It, together with the critical peer review by Szuladzinski, forced Bažant/Le to rewrite it three times, before being accepted as their final Closure paper in 2007, that first listed those 2 critical reviews, before countering them :

Oct. 2008 JEM Journal : Closure to “Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions” by Zdeněk P. Bažant and Mathieu Verdure from March 2007, Vol. 133, No. 3, pp. 308–319.
DOI: 10.1061/(ASCE)0733-9399(2007)133:3(308)
Closure article about the WTC Discussions, and embedded peer reviews and the replies on them.

Bažant thought thus in Oct. 2008 that he wrote a thorough rebuttal for the Gourley and Szuladzinski reviews, that countered most, if not all of their arguments, he thought.

However, Tony Szamboti recently ( June 2016) pointed his attention on three grave errors in the presumptions for his arguments in his four WTC publications.
Tony's paper plus letter to Prof. Bažant is posted further down.

So there's in JEM this 2007 Bažant/Verdure Paper, which relied on the crush down/crush up theory, titled :
“Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions” by Zdenek P. Bažant and Mathieu Verdure.

Dr. Gregory Szuladzinski, an Australian, wrote a peer review reply on that Bažant/Verdure paper, concluding that the by Bažant & Verdure proposed natural collapse would have been halted by the strain energy resistance at the first floor already :
Look up Szuladzinski's peer-review in there. CLICK this link.

In this same JEM Closure link from Oct. 2008, you can find at the end the extensive defense by Prof. Bažant on the Gourley and Szuladzinski peer reviews.
Of course his math and calculations are correct, when you accept his 3 erroneous presumptions.
Which presumptions were already countered by Gourley and Szuladzinski and are now ( June 2016) being countered by Tony Szamboti with more evidence. (see posts further on)

Page 914 JEM, Szuladzinski : The strain energy (as a measure of resistance to be overcome), which is needed to collapse the column, is larger than the potential energy available. The conclusion is that the motion will be arrested during the damaged story collapse and the building will stand.
-- snip --

Equating kinetic and strain energies gives a result of 7.238 x 10^9 ( read it ! )
This means a free fall from 3.69 m ( read it ! )
This is more than one story and is clearly beyond the range of possibilities.
-- snip --

In summary, the postulated failure mode is not a proper explanation of the WTC Towers collapse, as concluded from several criteria used previously. The visual evidence is not favorable to this theory, either. There was an absence of “kinks” or “elbows” from bent columns sticking out and visible in the early phase of the fall

Note that his first conclusion is exactly the same as that from Charles M. Beck, who found even greater discrepancies, read his 3 papers :
arxiv.org...
arxiv.org...
arxiv.org...

The potential energy was not at all big enough to overcome the inherent strain energy and initiate a natural collapse.
9/11 was a row of unnatural events, in other words, a row of demolitions.

In fact there were bent facade columns, but not outward sticking, but inwards bended, in a straight line following a 1/3rd part of one floor line, which is solid evidence for intact floor attachments to that facade. The huge composite floor pulled the facade line inwards, not solely the weight of the above building parts. You saw no floors sagging behind a row of windows in the high definition NIST photos [ NIST (2005), part NCSTAR-1, Chapter 2, p. 32 and Fig. 2–12 ].

What you saw in reality was a long length of lowered ceilings rims, made from angled-aluminum lengths, that was sagging down.
That means the floor was pulled back/down only at its connections to the center core columns. Which columns thus must have failed shortly before we saw the first signs of inward bowing of facade columns, and those cut center column rows were slowly sagging down (since the facade bending slowly grew deeper during about 22 minutes), to a point of no return, then the by mass-overload caused collapse initiation moment followed. Over about a one second period, the collapse proceeded diagonally from one facade corner to the opposite other corner, over the whole 98th floor build around the core and through the core column area of the North tower.

Bažant's Closure article, PDF-page 7/11 (art. p.920) : The fact that some perimeter columns showed gradually increasing lateral deflections, reaching as much as 55 in. (or 1.40 m) [ NIST (2005), part NCSTAR-1, Chapter 2, p. 32 and Fig. 2–12 ], cannot be explained as anything other than creep buckling of heated columns.
--snip--
The visible bowing of columns appears to have spanned about three stories, etc.

I just explained it OTHERWISE above.

Tony Szamboti : An Open Letter to Northwestern civil engineering Professor Zdeněk Bažant "to request that you correct your four papers on the collapse of the WTC Towers, which were published by the Journal of Engineering Mechanics." (June 19, 2016) :
(CLICK this Link).

I don't know what happened there at Reddit, but that page seems empty now.
Perhaps their sidebar links may be interesting for the residential stubborn Trusters.
Their editors could be leaning to the official lies, or Tony got upset and deleted it.? But I don't think you can delete your submitted text there. You probably have to keep clicking their links.

Luckily, we can still read Tony's June 19, 2016, most interesting short paper in full at AE911Truth.org :

Title : Mechanical Engineer Sends Open Letter to Main Defender of the 9/11 Official Account, Zdeněk Bažant.
CLICK this LINK.

Here's Tony's letter in a 3 page PDF form :
Open letter to Professor Zdenek Bažant regarding errors in his WTC analyses.

He offers 3 misconceptions by Prof. Bažant et al. in their four former publications written up till this date, which consequently strongly favored a naturally induced collapse propagation, after an initiation event.
These are the first two grave ones, Bažant's velocity and mass misconceptions :

Dear Professor Bažant,

This open letter is being sent to you to request that you correct your four papers on the collapse of the WTC Towers, which were published by the Journal of Engineering Mechanics.

In these papers, the values used for the below three items:

* The velocity of the descending upper section of the building
* The mass of the descending upper section of the building
* The column strength of the underlying story at the impact floor

have been shown in the intervening years to be significantly unrepresentative of the actual situation concerning the North Tower (WTC 1) at the time of its collapse.

Drawing by Tony Szamboti :


LT : Velocity decrease in the first second already calculated by Tony for a natural collapse. Calculated by him with the correct mass, acceleration through 1st story, plastic moment, and conservation of momentum.
However no velocity decrease measured for the North Tower by David Chandler.

This is a very important correction on the Bažant data, and I am really curious how Prof. Bažant et al. will react on this open letter, addressing the 3 grave errors Tony et al. found.
While David, years ago already, made the obvious non-deceleration visible for the collapsing WTC-1N top-corner part, in the first 3.5 seconds of global collapse.

-- more --

Tony Szamboti : By your use of free fall through the first story of the collapse it would seem that you had not measured the descent from video. Others have measured it, and the velocity after a fall of one story is approximately 6.13 meters/sec and not the 8.52 meters/sec velocity, resulting from a free fall through one story, used in your papers. This leads to a near doubling of the velocity component in the kinetic energy of the upper section, since it is squared with 6.13^2 = 37.58, while your velocity is squared with 8.52^2 = 72.59.

(LT : I expanded/explained this last line of text only a tad bit, to make things clearer for the casual reader, this is Tony's original text :
- - ,since it is squared with 6.13^2 = 37.58, and 8.52^2 = 72.59.)

Your papers show a mass of either 58 x 10^6 kg or 54.18 x 10^6 kg for the descending upper section, which seem to correspond to 15 or 14 stories at the 3.87 x 10^6 kg per story mass given in two of your papers. The collapse initiation in the North Tower actually occurred at the 98th story and the actual in-service load of the 12 story upper section can be calculated, based on story masses from the NIST report, as 33 x 10^6 kg. This would equate to an average of 2.75 x 10^6 kg per story.

Interestingly, in the second page of the addendum to your first paper (Bažant and Zhou 2002) you used the vibration period of the tower (14s) to estimate the mass of 44% of the 117 stories of the tower as 141 x 10^6 kg. If this partial mass is divided by 0.44 it gives a full mass of 320.45 x 10^6 kg for the whole tower. When this full mass is then divided by 117 stories it gives 2.74 x 10^6 kg per story. This is very close to what can be discerned from the NIST report and thus your own calculations tend to confirm it.

(LT : Each tower consisted of a 110-story above-grade structure and 6-story below-grade structure.)

It is thus confounding as to why you used a 3.87 x 10^6 kg per story mass in your papers. This per story mass seems like a maximum design load and not the actual in-service load. Use of a maximum design load, when that is not what was present during the failure, will prevent any forensic analysis from being accurate.

The overestimates of velocity and mass of the descending upper section in your papers cause it to have a kinetic energy which is several times what it actually would have been. Of course, this would make a collapse propagation more likely.

Which natural collapse propagation seems indeed the goal Prof Bažant had set for himself to prove. Which is against all basic rules for honest science : first you have to measure in full neutrality, than conclude in neutrality.
Not the other way round, while throwing during that process strict neutrality overboard.
-- more --

Now on to the third misconception, the column strength of the underlying story at the impact floor (I added links to the indicated Bažant papers, so the readers have the opportunity to cross-check it all for themselves) :

In your January 2011 paper (Le and Bažant) you show a total cross sectional area, for the 287 columns on the underlying story at the impact floor, of 6.05 m2. This would be for an average 14 inch square box column with a wall thickness of 15.49 mm (0.610 inches). However, you then give an average yield bending moment of 0.32 MNm, which calculations show would be for much thinner, weaker, and less energy dissipative, 14 inch square box columns with a wall thickness of 6.75 mm (0.266 inches) These 6.75 mm wall columns would only give a total cross sectional area of 2.70 m2.

It does not make sense that you would give a total cross sectional area of 6.05 m2 and then give an average yield moment for columns having a total cross sectional area of 2.70 m2.

The actual total column cross sectional area at the 97th floor for the 287 columns is approximately 4.00 m2 and the average yield moment there is approximately 0.75 MNm.

In other words : Bažant takes a value of 6.05 m2 steel for a total cross sectional area for the 287 columns on the underlying story at the impact floor, which value is for average 14 inch square box columns with a ( thick.! ) wall thickness of 15.49 mm (0.610 inches).
Then he incorrectly calculates an average yield bending moment of 0.32 MNm for those thick columns that were actually placed at that floor, which value of 0.32 is however for much thinner, in fact 6.75 mm (0.266 inches) wall thickness columns, with a total cross sectional area of just 2.70 m2 steel, and an average yield bending moment of 0.75 MNm.
Which means that the actual resistance of the steel at that floor against bending or buckling is 2.3 times stronger than Bažant came up with.
Which is also obvious by the 2.3 times thicker walls of those steel columns.

Just like Charles M. Beck also indicated already ( arxiv.org... ).

Additionally, in the 2011 paper, the mass of one story, used for the conservation of momentum loss calculation, is shown as 0.627 x 106 kg. However, as mentioned above, in earlier papers you show it as 3.870 x 106 kg. The use of this lower figure in your calculation causes velocity loss due to conservation of momentum to be just 1.1%. With the greater mass it would have been about 7.1% from conservation of momentum alone, without even considering the column resistance losses yet. It seems this 0.627 x 106 kg mass is that of just the concrete slab.
It does not include all of the additional mass on a story, which would bring it to the 2.750 x 106 kg mass that NIST shows, and that you also determined, but did not use, with your vibrational period and a concentrated mass on a massless cantilever analysis.

In the 2011 paper, you claim that the velocity loss would only be about 3% and thus too small to observe with the available video resolution. However, that would be far from the case if you corrected the velocity, mass, and column size to reflect the actual conditions.

A Canadian professor, Richard Johns, and I did submit a Discussion paper to the Journal of Engineering Mechanics in 2011 regarding these errors and they took 27 months before finally telling us our Discussion was “out of scope”, although it only discussed your January 2011 paper and corrected its errors.

I am not sure if you are aware of this and am attaching a letter on our experience, which also includes our Discussion of your paper.

The actual velocity loss would in fact be in comparison with the deceleration lines in the below diagrams of a natural collapse, for two different total masses :





The straight downwards leading line with its uncertainty borders shows the from video material by David Chandler in reality measured acceleration, which is a constant one, during the 3.5 seconds period of possible measurement. There's no obvious deceleration.

REFERENCES

Le, J. and Bažant, Z. (2011).
"Why the Observed Motion History of World Trade Center Towers Is Smooth."
J. Eng. Mech., 10.1061/(ASCE)EM.1943-7889.0000198, 82-84.
dx.doi.org...(ASCE)EM.1943-7889.0000198

Szuladziński, G., Szamboti, A., and Johns, R. (2013).
"Some Misunderstandings Related to WTC Collapse Analysis."
International Journal of Protective Structures, June 2013 vol. 4 no. 2, 117-126
dx.doi.org... pages 117-126.
Online publication date: 1-Jun-2013. prs.sagepub.com...
Full to pay-for text PDF : prs.sagepub.com... US$40.00.
Another pay-for link : ascelibrary.org...
CLICK here for the full and FREE to read, June 2013 Int.Journal of Protective Structures text, and also the included September 2014 letter to Bažant.

Abstract :
This article elaborates on variables associated with the collapse of the North Tower of the World Trade Center. The previously published quantification of inertia, column capacity, and the assumptions related to the beginning of downward motion, are examined and corrected. The reasons for false conclusions reached in several previous analyses are presented.

-- more --

Just read the three Charles M. Beck papers in the Cornell University Library -again?-, and the June 2013 arguments of Szuladziński, Szamboti and Johns become even more obvious :

"Mathematical Models of Progressive Collapse and the Question of How Did the World Trade Centers Perish" (15 pages, 7 figures) :
arxiv.org...
PDF full text : arxiv.org...

ABSTRACT :
We derive discrete and continuous class of mathematical models that describe a progressive collapse in a fictional one-dimensional structure, where we consider plastic and elastic types of collisions.

We examine static (collapse initiation lines, derived from the ultimate yield strength of the structural steel) and dynamic (duration of collapse, computed using mathematical models) features of events that comprised the collapse in WTC 1 and 2.

We show that
(a), the dynamic and static aspects of the collapse are mutually consistent and weakly dependent on the class or type of mathematical model used, and
(b), that the NIST scenario, in which the buildings collapse after a sequence of two damaging events (airplane impact and subsequent ambient fires), is inconsistent with respect to the structural strength of the buildings.

Our analysis shows that the force that resisted the collapse in WTC 1 and 2 came from a single structural element, the weaker perimeter columns, while the second structural element, the stronger core columns, did not contribute.

We discuss two non-obvious inconsistencies between the mathematical models of progressive collapse based on the NIST scenario, and the practical realizations of collapse in WTC 1 and 2 :
(i), the average avalanche pressure is 3 orders of magnitude smaller than the pressure the vertical columns are able to withstand, and
(ii), the intact vertical columns can easily absorb through plastic deformation the energy of the falling top section of the WTCs.

We propose collapse scenario that resolves these inconsistencies, and is in agreement with the observations and with the mathematical models.

"Role of Compaction Ratio in the Mathematical Model of Progressive Collapse" :
arxiv.org...
PDF full text : arxiv.org...

ABSTRACT :
We derive a mathematical model of progressive collapse and examine role of compaction.

Contrary to a previous result by Bažant and Verdure, J. Engr. Mech. ASCE 133 (2006) 308, we find that compaction slows down the avalanche by effectively increasing the resistive force.

We compare currently available estimates of the resistive force, that of Bažant and Verdure (2006) corrected for compaction for World Trade Center (WTC) 2, and of Beck, www.arxiv.org:physics/0609105, for WTC 1 and 2.

We concentrate on a damage wave propagating through the building before the avalanche that figures in both models:
* an implicit heat wave that reduces the resistive force of the building by 60% in Bažant and Verdure (2006), or
* a wave of massive destruction that reduces the resistive force by 75% in Beck (2006).

We show that the avalanche cannot supply the energy to the heat wave as this increases the resistive force by two orders of magnitude.
We thus reaffirm the conclusion of Beck (2006) that the avalanche is initiated in the wake of the damage wave.

How many times I already told you to study the three Charles M. Beck papers.?
Compare his arguments and values now with the ones from the four papers published by Bažant et al. during the last 15 years.

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"Descent curve and the phases of collapse of WTC 7" (24 pages, 7 figures):
arxiv.org...
PDF full text : arxiv.org...

Abstract :
We examine four WTC 7 descent curves, labeled "C," "E," "N," and "O," either anonymously published, or confidentially communicated to us. Descent curve describes apparent height of a collapsing building as a function of time.
The set "C" suggests that there are three active phases of collapse.
Phase I is a free fall for the first H1 =~ 28m or T1 =~ 2.3s, during which the acceleration a is that of the gravity, a = g = 9.8m/s^2.
In Phase II, which continues until drop H2 =~ 68m, or T2 =~ 3.8s, the acceleration is a =~ 5m/s^2,
while in Phase III which continues for the remaining of the data set, a =~ -1m/s^2.

We propose that the collapse of WTC 7 is initiated by a total and sudden annihilation of the base (section of the building from the ground level to H1), which then allows the top section (building above H1) to free fall during Phase I, and then collide with the ground in Phase II and III.
The total duration of the collapse, assuming that Phase III continues to the end, is in the range 7.8−8.6s.
We derive a physical model for collision of the building with the ground, in which we correct the "crush-up" model of Bažant and Verdure, J. Engr. Mech. ASCE, [bf 133] (2006) 308, and estimate the magnitude of the resistive force in the top section.

We compare our findings to those of NIST investigators and find an agreement with respect to the distribution of damage in the primary zone. We conclude that the building was destroyed in a highly controlled fashion.

In other words, Beck's conclusion is, just as the one from Gourley, Szuladziński, Szamboti and Johns (when using in their calculations the actual conditions, being different, more practical values than Prof. Bažant et al. used in four consecutive Journal papers. ) :

A natural collapse initiation and subsequent propagation could have never been possible without additional aid from explosives.!

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I did an arXiv references & citations query (similar articles bibliography) at SAO/NASA ADS for his first article, and found his three arXiv articles listed there as the first 3, plus one other interesting 4th arXiv one, and 1,164,899 other arXiv ones which I have to walk through their titles by speed reading, later :

"Progressive Collapse Mechanisms of Brittle and Ductile Framed Structures" (Sept. 2015)
by : Masoero, Enrico; Wittel, Falk K.; Herrmann, Hans J.; Chiaia, B. M. (16 pages)
PDF full text : arxiv.org...

Abstract :
In this paper, we study the progressive collapse of 3D framed structures made of reinforced concrete after the sudden loss of a column. The structures are represented by elasto-plastic Euler Bernoulli beams with elongation-rotation failure threshold. We performed simulations using the Discrete Element Method considering inelastic collisions between the structural elements. The results show what collapse initiation and impact-driven propagation mechanisms are activated in structures with different geometric and mechanical features.
Namely, we investigate the influence of the cross sectional size and reinforcement 'alpha' and of the plastic capacity 'beta' of the structural elements. We also study the final collapse extent and the fragment size distribution and their relation to 'alpha', 'beta' and to the observed collapse mechanisms. Finally, we compare the damage response of structures with symmetric and asymmetric reinforcement in the beams.

A lot of it can't be used as comparison to the above articles, since it solely studies reinforced concrete structures. But big parts of the calculations are also applicable to steel columns when their applicable data are inserted.

One thing's for sure, the 4 authors their extensive referencing f.ex. in their Introduction, by clickable links to 19 full PDF's in arVix publication format, about the former and latest insights about progressive collapse, alternate paths for the load (Alternate Load Path Method (ALPM) and high toughness of structural members and their interconnections, is extremely helpful for the investigative minds in the pro and contra 9/11-Conspiracy communities.

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Excerpt from their Introduction :

For instance, we know that the loss of external columns from the facades or the corners of a buildings are the most serious scenarios where, according to the ALPM method, one column is instantaneously removed (see, e.g. (Kaewkulchai and Williamson, 2003)). Moreover, it was shown that beam-column connections are critical points of failure initiation (Khandelwal et al., 2008) and that catenary effects in the floor slabs can remarkably improve robustness (Vlassis et al., 2006).
Even though the final outcome of progressive collapse depends on the collisions between structural elements, most of literature focuses on collapse initiation. Collisions are rarely taken into account either detailed with Finite Elements (Hartmann et al., 2008; Luccioni et al., 2004), or approximated in the framework of Finite Macro-Elements (Kaewkulchai and Williamson, 2006; Grierson et al., 2005). Detailed Finite Elements are too demanding in terms of computational time for extensive parametric studies on large structures. Differently, Finite Macro-Elements are efficient and can be applied to large structures, but they require strong approximations to take into account collisions and catenary effects, especially in 3D (e.g. see (Isobe and Tsuda, 2004)).
The lack of experimental results of progressive collapses suggests an approached based on simulations whose reliability arises from the basic physics incorporated. The results obtained with such algorithms can be used to construct, test and calibrate simpler models. In this work, we use spherical Discrete Elements (DE) to simulate the progressive collapse of typical 3D framed structures made of reinforced concrete with fixed regular overall geometry (see Sec. 2).
The aim is to study the collapse initiation mechanisms due to dynamic stress redistribution, and the subsequent damage propagation mechanisms due to collisions between the structural elements. Understanding the activated mechanisms, depending on the strength, the stiffness and the plastic properties of the structural elements, can help to choose optimal robustness oriented design solutions as well as the most appropriate structural reinforcement of existing buildings. We perform parametric studies scaling the cross sectional size and reinforcement by the cross sectional scale factor 'alpha' and varying the plastic capacity 'beta' of the structural elements (see Sec. 3). In this way, we show the expected collapse mechanisms and the final consequences of progressive collapse in terms of final collapse extent and fragment size distribution for various ( 'alpha', 'beta' ). Finally, in Sec. 4 we compare the damage response of structures with symmetric and asymmetric reinforcement in the beams.

Only in this section alone are 8 clickable links that lead to full PDF's of engineering and physics publications that are all highly applicable for studying the initiation of the three 9/11 collapse cases.

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F.ex. the citation : arxiv.org...-2008
is this recent article arxiv.org... from Sept. 2015, titled :
Progressive Collapse Mechanisms of Brittle and Ductile Framed Structures.
Its References section (page 13 of 16) leads to a plethora of other progressive collapse analysis publication-references f.ex. :

B.M. Chiaia and E. Masoero. Analogies between progressive collapse of structures and fracture of materials. Int. J. Fract., 154(1-2):177-193, 2008.

D. Hartmann, M. Breidt, V. van Nguyen, F. Stangenberg, S. Hoehler, K. Schweizerhof, S. Mattern, G. BlankenHorn, B. Moeller, and M. Liebscher.
Structural collapse simulation under consideration of uncertainty - fundamental concept and results. Comput. Struct., 86(21-22):2064-2078, 2008.

D. Isobe and M. Tsuda. Seismic collapse analysis of reinforced concrete framed structures using the finite element method. Earthq. Eng. Struct. D., 32(13):2027-2046, 2004.

Perhaps Charles M. Beck or Tony Szamboti/Prof Richard Johns could use parts of this last one to use for steel framed structure cases, like WTC-7, for which we also have some seismic data during its collapse.

B.M. Luccioni, R.D. Ambrosini, and Danesi R.F. Analysis of building collapse under blast load. Eng. Struct.,26:63-71, 2004.

S. Marjanishvili and E. Agnew. Comparison of various procedure for progressive collapse analysis. J. Perform. Constr. Fac., 20(4):365-374, 2006.

R.S. Nair. Progressive collapse basics. Modern Steel Constr., 44(3):37-44, 2004.

K.A. Seffen. Progressive collapse of the world trade center. J. Eng. Mech.-ASCE,134(2):125-132, 2008.

D.V. Val and E.G. Val. Robustness of framed structures. Struct. Eng. Int., 16(2):108-112, 2006.

A.G. Vlassis. Progressive collapse assessment of tall buildings. PhD thesis, London Imperial College, UK, 2007.

A.G. Vlassis, B.A Izzudin, A.Y. Elghazouli, and D.A. Nethercot. Design oriented approach for progressive collapse assessment of steel framed buildings. Struct. Eng. Int., 16(2):129-136, 2006.

Then Tony Szamboti concludes his letter to Prof. Bažant with this :

The NIST stopped their analysis at a point where the report says the building was “poised to collapse” when the south exterior wall purportedly buckled. There is no analysis or explanation provided in the report for the horizontal propagation across the building. The NIST report simply moves from a single buckled exterior wall to your analysis for substantiation of vertical propagation. I am not sure if you are aware, but the actual horizontal propagation occurs from the southwest to northeast corners (a distance of nearly 300 ft.) across the 98th floor of the North Tower in less than a second. The measurement of the vertical descent/propagation does not show any deceleration, at any time. Focused ejections can be observed emanating from the corners and the sides of the building during the collapse. None of these three observations can be explained easily as being due to naturally caused occurrences, but can easily be explained by the use of charges.

Unfortunately, the possibility that there were charges in the buildings has not been investigated up to this point and it would appear that your papers, with these errors still intact, have provided some level of umbrage for those who presently insist it is not necessary. It is hard to believe you would approve of that knowing there are errors. It is sincerely hoped that you will correct these errors now that they have been brought to your attention. Once they are corrected your analyses can no longer be used as an argument against a new investigation to look into those things which were missed in the first attempt to investigate these collapses.

Sincerely,

Anthony Szamboti

CC :
Office of the president of Northwestern University.
Dean of the Engineering School at Northwestern University.
Office for Research Integrity at Northwestern University.
Architects & Engineers for 911 Truth.
Journal of 911 Studies.

That will rattle some protected elite niches in academic circles.
================

And certainly after reading Tony Szamboti's earlier published grave accusations against Prof. Bažant :

Tony Szamboti's white-paper with his 25 points, see Point 22 :
NO JOLT - CONTINUOUS ACCELERATION OF COLLAPSE WAS IGNORED.

All of Dr. Bažant’s papers use free-fall acceleration through the first story and the maximum design load mass of the falling upper section. Neither of these are representative of the actual situation, so this causes an embellishment of the upper section’s kinetic energy in his papers. He also significantly under-estimates the energy dissipation due to column deformation during impact. Dr. Bažant has been made aware of these problems with his hypothesis, and in January 2011 he had a paper published by the Journal of Engineering Mechanics where, with a graduate student as his co-author, he tried to claim the deceleration would not be observable. This paper has been shown to use fraudulent values for both inertial and column deformation energy losses.
However, NIST continues to use his work.

Recent research using test results versus the three-hinge method for estimating energy dissipation caused by plastic hinge formation in axially-loaded buckling columns has shown the three-hinge method to significantly underestimate it —and this is without using fraudulently low column plastic moment (Mp) values, as Le and Bažant did in their Jan. 2011 paper.
This research provides even more support for the contention that the lack of deceleration in the descent of WTC 1 is a severe impediment for a natural-collapse scenario.

Let's hope Prof. Bažant et al. will react soon on the June 2016 open letter. My guess.? He will not risk his career by coming out from protective academic circles with his own open letter.
He could ignore it, based on longstanding academic rules. If it's not published in any Journal, it can be ignored.
However, the accusation of using fraudulent research values in Tony's white-paper letter should in this 9/11-case of international importance, be reason enough to force him to react.
Tony has no other option left, since his and Prof. Johns submission is being rejected by JEM, after 2 years and 3 months waiting for the decision of the editor of the JEM journal, to not publish that submission.
That 2013 decision by the editor of JEM to not publish that 2011 Discussion paper, written by Tony Szamboti and Professor Richard John's, was based on a really short and vague reason :
It was "out of scope"....although it only discussed the Bažant and Le, January 2011 paper, and corrected its errors.

Remember that I mentioned again and again that there were no sagging floors to see in the NIST photos, floors NIST thought were detached from the huge and thick spandrel plates welded onto the back side of each Vierendeel facade columns triplet.
Those composite floors were still firmly attached to the spandrel plates welded behind the facade its Vierendeel triplet columns, as proven by the straight and horizontal line of inward buckling facade columns in other NIST photos of inward bowing perimeter columns.

And some perhaps remember why I am so sure about that :
Because the reinforced concrete on metal floor decks, were not attached alongside the facade there, at the positions where the inward bowing occurred, but perpendicular to that part of the facade.
And I showed you the actual tower-during-construction photos, where you can see those trussed floor segments laid out perpendicular against the same WTC-1N South facade, that during 9/11 showed its 1 to 1.4 meter inward buckling line.

Meaning the end of all those collapsing floors stories, based on NIST-photos from that particular facade side showing that long sagging dark line behind those windows.
Which was actually a long lowered ceiling-rim made of lengths of angled aluminum where the vermiculate ceiling plates fitted in.
And it means the end of the Bažant double crush-theories, based on the fairytale of those sagging floors.
Which observation nullifies immediately any theories about a collapsing floor at collapse initiation, followed by a progressively extending global building collapse.

Cut outer-core column rows were the cause.
9/11 was a demolition job.
Get used to it.