911 Debate Nukes Vs No-nukes, between open-minded folks Options

[DoYouEverWonder]

There is no way that those buildings would collapse any way but straight down regardless of how the structure was "dismembered" It would take enormous energy to get them moving laterally.

Both tops did tilt before they dropped down... the south 20° to the se and the north tower to the south 8°. In each case the sufficient amount of columns were destroyed or pushed out of alignment and they tilted. When the titling part encountered the standing part the crush up and crush down tool place the upper part started to come apart... and then the explosions came and the real show started.

The only reason for squibs in the center as far as I can tell would be if they were on the north or south face of the north tower and the east and west face of the south tower. These would be in line with the space which went through the core... dividing the express elevator shafts. However the key columns to destroy would be the 4 corner columns of the core 501, 508, 1001 and 1008 which carried 2 x the load of most of the other core columns and 30% of the floor load.

If dropping a bunch of floors was the mechanism for collapse... they would place explosives at the 36' long columns. This would begin to destabilize 6 floors with one blast. And to drop the floors, only 12 beam stubs connecting the core columns to the girders which supported the floors would be required.

The floors spanned from the girders surrounding the core to the facade columns. What would happen if the girder was detached from the columns? The floors would now be completely supported by the facade. The floors would also likely as square donuts collapse at the inside (core side) and pull (or break free) from the connections at the facade.

The facade depended on the floors to support them laterally. The collapsing floors might rip out a whole row or two of facade panels and the ones atop would be unsupported and this would lead to the entire floor system above to loose support on the facade side. Breaking the corners would certainly facilitate the facade loosing its stability as each faced provided lateral support the the adjacent facade. Breal the corners and the tube become four thin planes ready to topple.

The destruction likely took place at the mechanical floors and at about the same time. Once the first explosions went off their debris descended and concealed the others... which were likely not as powerful. Having 30 or 40 stories weighing a few hundred thousand tons dropping in an avalanche of concrete and steel will do a lot of damage to the structure below.

Fire did not get this one going, but once it got going gravity easily pulled the structure apart and the floors dropped, the facade peeled or was thrown away and the core structure mangled. Not a progressive collapse... more like an avalanche.

If you look at the bottom edges of the first large sections of panels that came down first, all of the columns broke straight across evenly. This would indicate that the first floor that failed was a mechanical floor. The columns on the mechanical floors were all set at the same height, which created that darker bands around the buildings. (The regular floors had columns that were staggered in sets of three). These are the floors that were built with beams, instead of trusses. According to NIST, WTC 2 failed at the 81st floor. 81 was a mechanical floor too. This is where they installed the elevator hoists and they needed to install beams and additional strengthening to carry the additional load. I would imagine cutting this load loose, would reduce the amount of explosives you might have needed otherwise.

The first panel at the bottom of the picture is at least 6-8 stories tall. So that section could be from between the 76th - 81st floors.


(IMG:http://www.libertynews.org.nyud.net:8090/wtc/wtc44.jpg)



WTC 2 collapsing, looking up from West Street.

[KP50]

The destruction likely took place at the mechanical floors and at about the same time. Once the first explosions went off their debris descended and concealed the others... which were likely not as powerful. Having 30 or 40 stories weighing a few hundred thousand tons dropping in an avalanche of concrete and steel will do a lot of damage to the structure below.

Fire did not get this one going, but once it got going gravity easily pulled the structure apart and the floors dropped, the facade peeled or was thrown away and the core structure mangled. Not a progressive collapse... more like an avalanche.

Except the "30 or 40 stories" never made it to the ground - it was also destroyed under cover of the dustcloud - imagine the impact of that much mass hitting the ground at one time ......

[SanderO]

Except the "30 or 40 stories" never made it to the ground - it was also destroyed under cover of the dustcloud - imagine the impact of that much mass hitting the ground at one time ......

I beg to differ. It did make it to the ground except that which was disbursed in dust clouds. It's what destroyed the building. it's likely that there were 3 areas of "attack"... the 9 mechanical floors separated by 31 tenant floors.

There was little to resist the mass over the collapsing floor areas - they were open area with long span truss joists. The explosion at the 75-77 destroyed the core and sent the heavy steel and concrete plunging down through the building's core which was mostly open shaftways. As the heavy steel frame plunged through the core it ripped the beams which supported the core columns laterally... they broke apart at their splices (there were many straight 36' columns in the debris)... and the floor support at the beam stubs carrying the girders were ripped apart.

I suspect the core offered less resistance to the falling debris than the floors outside it and in some vids it almost looks as if the core is diving down inside itself. I suspect the facade panels came off in large multi story sections because each one was 3 stories to begin with and they were staggered to boot and they had so few connections to the floors they supported. To me they being multi story section is indicative of the truss seats being sheared right off and the facade falling away as opposed to being exploded apart. The floors unzipped the panels as they plunged.

Since the building swayed so much from the plane impacts as reported by those who escaped, it's conceivable that many connections were compromised and weakened if the movement was outside of the design spec.

[Paul]

Why are we even discussing this it's not like we can prove anything really what have we proven so far as far as thtowers being a controlled demolition of sorts, the day someone proves that nukes where used on twin towes or some kind of solid proof of cd when that day comes
you wont have to worry about me because i will drop dead and roll over of a heart attack, by the wa what have we proven? Because I have no idea what is going on have we found the smoking gun yet where are all the smoking guns already ffs i get really tired and frustrated and searching
for any possible smoking guns.

[DoYouEverWonder]

I beg to differ. It did make it to the ground except that which was disbursed in dust clouds. It's what destroyed the building. it's likely that there were 3 areas of "attack"... the 9 mechanical floors separated by 31 tenant floors.

There was little to resist the mass over the collapsing floor areas - they were open area with long span truss joists. The explosion at the 75-77 destroyed the core and sent the heavy steel and concrete plunging down through the building's core which was mostly open shaftways. As the heavy steel frame plunged through the core it ripped the beams which supported the core columns laterally... they broke apart at their splices (there were many straight 36' columns in the debris)... and the floor support at the beam stubs carrying the girders were ripped apart.

I suspect the core offered less resistance to the falling debris than the floors outside it and in some vids it almost looks as if the core is diving down inside itself. I suspect the facade panels came off in large multi story sections because each one was 3 stories to begin with and they were staggered to boot and they had so few connections to the floors they supported. To me they being multi story section is indicative of the truss seats being sheared right off and the facade falling away as opposed to being exploded apart. The floors unzipped the panels as they plunged.

Since the building swayed so much from the plane impacts as reported by those who escaped, it's conceivable that many connections were compromised and weakened if the movement was outside of the design spec.

I think the buildings were compromised to begin with, even before the attack.

The perimeter curtain walls were only bolted together, instead of welded and the buildings were designed to sway a fair bit. I think that between the sway and the salt air, these buildings were having serious issues with loose bolts and corrosion issues that probably developed over time where they had attached the aluminum cladding to the steel columns. They had similar problems with the Citicorp Building.

[KP50]

I beg to differ. It did make it to the ground except that which was disbursed in dust clouds. It's what destroyed the building. it's likely that there were 3 areas of "attack"... the 9 mechanical floors separated by 31 tenant floors.

It was 30 stories which was basically "intact" when the collapse started - it should have hit the ground basically "intact" especially the top floors which would have been above the collapse. But they aren't on the ground, there is nothing "whole" on the ground at all. That's not a technical description but it is basically 25% of the building height which would have been a tall building in its own right. Not to mention the carnage when it hit the ground, all of that mass at the same time. A 30 story tower block hitting the ground having been dropped from a height?

[JimMac]

It was 30 stories which was basically "intact" when the collapse started - it should have hit the ground basically "intact" especially the top floors which would have been above the collapse. But they aren't on the ground, there is nothing "whole" on the ground at all. That's not a technical description but it is basically 25% of the building height which would have been a tall building in its own right. Not to mention the carnage when it hit the ground, all of that mass at the same time. A 30 story tower block hitting the ground having been dropped from a height?

This point is great. What happened to the upper section of the building? Its crazy when you stop to think about it, the NIST pile driver scenario (impossible as it is) only addresses the lower 2/3 of the building. BTW, how did NIST deal with that? Or did they.

edited to add: oh, i forgot, NIST only dealt with the phenomena 'up to the point of collapse'. Scratch that question..

This post has been edited by JimMac: Apr 22 2010, 11:33 PM

[lunk]

Is there anything to the story that big buildings must have a demolition plan before the construction could begin?
Apparently someone discovered the demolition plans for the twin towers in a public library in 1980 or 82, and there was a bit of a fuss about it.
The mind set of the 60's was that nuclear weapons could be peacefully used for big building demolition.

How can this be verified?

[JimMac]

Is there anything to the story that big buildings must have a demolition plan before the construction could begin?
Apparently someone discovered the demolition plans for the twin towers in a public library in 1980 or 82, and there was a bit of a fuss about it.
The mind set of the 60's was that nuclear weapons could be peacefully used for big building demolition.

How can this be verified?

I don't know about verify, would you settle for 'certify'? It's certified hogswaddle.

[JimMac]

A nice little paper on load distribution for WTC1.

Load Distribution and Load Capacity inthe Core of WTC1

This post has been edited by JimMac: Apr 23 2010, 12:57 AM

[lunk]

I don't know about verify, would you settle for 'certify'? It's certified hogswaddle.

i just found the NYC building codes for 1968.
They are zip, pdf, filed and seem to all be crossed out, but are still readable.
There may be something useful in here.


http://www.nyc.gov/html/dob/downloads/bldg...ngCode_Vol1.zip

http://www.nyc.gov/html/dob/downloads/bldg...ngCode_Vol2.zip

No, i haven't gone through it all yet.

[Ricochet]

I just went through the first zip file. Nothing out of the ordinary, permits, fees, duration blah blah blah. Zip 2 same thing. Enter demolition or explosive into search and just standard fare with a dash of leagalize.

This post has been edited by Ricochet: Apr 23 2010, 12:51 PM

[GroundPounder]

right, designed to stand up to hurricane force winds, but a puny plane brings it down. sure, and thermal expansion too.

[SanderO]

The buildings were under severe stress and once the upper parts came apart tens of thousands a material came crashing down. It's likely that there was also destruction lower down in the buildings which may have initiated collapse and dissociation of the structure. Which was seeing an avalanche of 100s of thousands of tons of debris crashing down.

The floor connections to the columns were much weaker then the columns themselves as each column carried the floor loads above so the columns were stronger as you descended but not the floor system connections. Any individual set of floor connections could carry one floor load with a safety factor, but not multiple floor live loads and each floor weighed in at 500 tons an another 500 tons of live load (3/4 of an acre of office furniture equipment partitions etc.). One floor supporting two is overloaded 200% not counting the dynamic load and adding a third it's not trying to support 3500 tons instead of just 500 or 7 times its design load.

Once this overwhelms the connection to columns it sets of an avalanche of increasing mass and speed cascading down through the structure. Obviously this is not going to fall at free fall, but it is going to be accelerating. At 50% of FF it would take less than 20 seconds. And it didn't exceed free fall as the collapsing front was hidden by the free fall debris outside the towers and concealed the slower destruction.

There likely was additional attacks at the lower mechanical floors which assisted in the total disassociation of the structure. Gravity did it... but it likely wasn't started by the plane of the fires.

[JimMac]

The buildings were under severe stress and once the upper parts came apart tens of thousands a material came crashing down. It's likely that there was also destruction lower down in the buildings which may have initiated collapse and dissociation of the structure. Which was seeing an avalanche of 100s of thousands of tons of debris crashing down.

The floor connections to the columns were much weaker then the columns themselves as each column carried the floor loads above so the columns were stronger as you descended but not the floor system connections. Any individual set of floor connections could carry one floor load with a safety factor, but not multiple floor live loads and each floor weighed in at 500 tons an another 500 tons of live load (3/4 of an acre of office furniture equipment partitions etc.). One floor supporting two is overloaded 200% not counting the dynamic load and adding a third it's not trying to support 3500 tons instead of just 500 or 7 times its design load.

Once this overwhelms the connection to columns it sets of an avalanche of increasing mass and speed cascading down through the structure. Obviously this is not going to fall at free fall, but it is going to be accelerating. At 50% of FF it would take less than 20 seconds. And it didn't exceed free fall as the collapsing front was hidden by the free fall debris outside the towers and concealed the slower destruction.

There likely was additional attacks at the lower mechanical floors which assisted in the total disassociation of the structure. Gravity did it... but it likely wasn't started by the plane of the fires.

Not sure i'm following the picture in your mind's eye.

I see the contents of each floor being turned into particles by very energetic high explosives, and blown in the path of least resistance, which at the time-interval they occurred, there was resistance from below, due to the fact that the structure under was still whole and intact. So the blast debris vectors were 180 degrees from the horizontal plane, in all directions except down.

The picture has to account for the fact that 95% percent of the building mass in the form of debris was blown 'outside' the bldg footprint. Therefore only 5% of the exploded mass (after airborne or separated from the structure) could be considered to bear down on the remaining structure during the destruction sequence.

Are we more-or-less in agreement so far?

[lunk]

I just went through the first zip file. Nothing out of the ordinary, permits, fees, duration blah blah blah. Zip 2 same thing. Enter demolition or explosive into search and just standard fare with a dash of leagalize.

Part 2
i found a bunch of building codes for demolitions.
(demolition codes?!)
along with the building codes, in the file.

It still seems logical to me, that large buildings, especially in city centers,
should have a demolition plan, before they can be built.
...but i haven't found that particular regulation, yet.
(edit spelling)

This post has been edited by lunk: Apr 23 2010, 09:21 PM

[JimMac]

Part 2
i found a bunch of building codes for demolitions.
(demolition codes?!)
along with the building codes, in the file.

It still seems logical to me, that large buildings, especially in city centers,
should have a demolition plan, before they can be built.
...but i haven't found that particular regulation, yet.
(edit spelling)

I mentioned this on another thread, that buildings such as WTC are a case for demolition considerations in the design phase, but i was alluding more to the emphasis on WTC's superior strength, it was built not to be demolished, at least not easily, unless you consider piece by piece by crane easy.

Anyway, the final removal of buildings from a site (it may be said) is covered in the site plan policies of present day, namely in the bldg footprint to plan area ratio. There is a lot of open space allowed for tall structures (somewhere on the site).

This post has been edited by JimMac: Apr 23 2010, 10:00 PM

[SanderO]

The path of least resistance is really missing the point of what might likely have taken place. The resistance referred to is the columns. they are what hold up the structure (and themselves of course) and the floors were the live loads are.

The floor loads, what ever they are the weight of the floor system, the furniture and equipment, partitions and people is more or less the same for each floor (except the mechanical ones) The floors do not sit ON the columns like one thinks of legs under a table top. The floors are attached to the side of the columns both for the facade columns and the core columns.

The floor system was supported by those truss joists with a spacing equal to two perimeter columns or about 80" and these same trusses were supported by a steel girder which was then connected to the perimeter core columns.

The core columns varied in size and so to connect to the girders which supported the trusses beam stubs were bolted on to the columns. There was one beam stub per perimeter core column and perhaps 2 for the corners making minimum 24 and maximum 28 connections to the core to support the floor system. This was exactly the same on every tenant floor. None were stronger or weaker.

A chain is as strong as its weakest link and so it was with the floors system. The core perimeter was 448 feet long and was supported by 24 core columns. The 23 inner core columns had nothing to do with supporting the floors outside the core. The floors were connected every other column at the facade.

Facade columns were panels 3 stories high by 10' wide. The facade was about 800 feet in length on all four sides with 19 x 3 or 57 columns per side and one at the beginning and end which were part of the corners. This meant there were 28 connections of the floor system on each of the four facades making it 112 supports on the facade side and 24 or 28 on the core side of the truss joists. The corner support worked with 2 way support and were also carried on a transfer girder which was and extension the girders on the two long sides. So you have 140 or so truss seats supporting each floor and connected to the girder or the columns with 2 - 5/8" bolts on each end.

What would happen if all the beam stubs were destroyed on one floor? the floors would have no support at the core column side. Would this be enough to overload the connections at the facade enough for them to fail? Let's say perhaps. If they failed the floor would then drop down to the next floor. Now this floor is supporting 2 floors of loads. What happens if the beam stubs of that floor were also destroyed? It too would drop even if they could support 2 floor loads without the stubs to tranfer the load to the columns the two floors would drop on the next. And so on.

Now this sounds like the pancake theory which was thought to be incorrect. However I don't think it was one floor dropping then two and so forth. I am proposing that the stubs on 6 or more floors were destroyed by cutter charges or explosives at once releasing 6 floors to drop at free fall acceleration. I am quite certain that if this was the scenario the 6 floors would cascade very quickly through the building. They were not falling through the path of most resistance... that would be the columns. They were falling between the perimeter and the core columns where the resistance was the 140 truss connection to 112 perimeter facade columns and 24 core columns.

Notice that parts of the core stood for a bit after the floors and facade was destroyed. The avalanche largely took place outside the core and only involved the perimeter core columns at best.

So what happened to the facade panels? The plunging mass of floors unzipped the facade. The facade supported the floor loads but the floors held the face laterally. One might think that the floors could plunge right to the bottom inside the tube of the exterior leaving the core standing inside. But I suspect that other things were going on which allowed the facade to topple over away from building in massive sections. (see vids of tower one). Something destroyed the perimeter core columns all around at about the crash zone at collapse initiation. This may have been explosives or incendiares. But the "tube" was substantially severed from the top section.

There is evidence that the corners of the facade were attacked as well. With the corners not connecting the adjacent facades to one another they were no longer a tube, but 4 tall rows of columns 192 feet wide and 1000+ feet high and 14" thick. With the top severed at about the crash zone and the corners destroyed the dropping mass of floors would slice off the the connections to the facade and there would be nothing to support it laterally. It would begin falling from the top where it was disconnect at the crash zone first. The crashing floors peeled it away from top to bottom.

The floors did not drop like a stack of records on a changer (do you remember them?). The collapse would be quite chaotic... and be like an vertical avalanche within the volume of the core and the facade. This avalanche would hurl material into the core and at the facade breaking the joints of both - likely not bending them. The splices were the weakest point in the system. The vast majority of the steel broke apart at the splices and this is why there were so many straight sections at the end. Obviously some would be mangled and bent, but many fell apart like dropping pick up sticks. The avalanche of the floors was contained by the facade a bit but the debris pushed at it and it went over. The core columns did the same. They were not crushed and there was no large number of buckled columns... their joint connection one to the other were destroyed and they toppled into the core which was largely shafts with little or no resistance.

Sure the mass of the top was much less than the mass of the bottom and if we were talking two blocks of wood the small top could not crush the big bottom block. But that is not the correct analogy.

This avalanche took more than a free fall drop would take.. perhaps 2 times or 15 - 20 seconds. The avalanche did have to break the floor connections either at the beam stubs or at the truss seats (or both) which would go first in the avalanche. But the initiation was like an attack at a half dozen or less continuous floors probably up at the 75, 76 and 77th mechanical floors.

Another thing to note is that the twins were constructed of columns of 3 stories in height. An explosion at the joint between a core column would disturb the support of 6 stories. What would happen if there was 12 or more explosion on a single floor at the location of the beam stubs close to where the columns were spliced to each other? That might get 6 floors dropping at once and begin the avalanche. No?

Also once the tops were dissociated from the bottom what you had looking up is 24 core columns which were connected to the entire floor loads of the upper section and all the facade columns. If there was any lateral motion when gravity pulled the top down to meet the bottom it's likely that the resistance was not the columns meeting column but columns meeting the floor, or voids in the core. It would be like pushing two hair brushes at each other. The force is concentrated in the few bristles (columns) not spread out over 40,000 SF of floor. The top coming down into the bottom would face the same fate. Strong columns like the bristles of one brish poking though the floors and into the voids in the core. It would he like jamming two brushes at each other with bristles ripping past one another (and crushing the weak floor systems between them)

All the notion of path of most resistance is hooey. It does not describe the forces at work in a dissociated structure.

The above does not mean that fires from office materials and jet fuel did this. It's more than likely that a very few strategically placed explosives and incendiaries could release enough stored potential energy to create an avalanche which would destroy the structure in 15 seconds.

Gravity did it. What unleashed the gravity? That is the question.

[SanderO]

Not sure i'm following the picture in your mind's eye.

I see the contents of each floor being turned into particles by very energetic high explosives, and blown in the path of least resistance, which at the time-interval they occurred, there was resistance from below, due to the fact that the structure under was still whole and intact. So the blast debris vectors were 180 degrees from the horizontal plane, in all directions except down.

The picture has to account for the fact that 95% percent of the building mass in the form of debris was blown 'outside' the bldg footprint. Therefore only 5% of the exploded mass (after airborne or separated from the structure) could be considered to bear down on the remaining structure during the destruction sequence.

Are we more-or-less in agreement so far?

The mass of the facade fell away pushed outside the foot print by the falling floors. The core fell mostly inside or close to the footprint. The concrete was pulverized in the avalanche and some sections of the building exploded out (but not much). Much of the pulverization made dust which propagated through lower Manhattan and some mass when up in smoke. Much of the concrete and gypsum became something ground up to the consistency of dirt and filled the footprint in 7 basements and 4 or 5 stories above grade. The debris pile was a mound as would be expected.

If the facade supported half the building loads and were half the weight of the steel and fell away a good portion of the mass lay outside the foot print.

So have the steel was out, half was mostly inside and close to the footprint and the floors and contents were mostly centered in the footprint or disbursed as dust outside the footprint. The concrete weighed ~86,000 tons per building. The facade steel was about 30,000 tons per building and the core was similar. The building was said to weigh 500,000 tons, but that's probably way over what it weighed... more like 300,000 tons.

[JimMac]

The floors do not sit ON the columns like one thinks of legs under a table top. The floors are attached to the side of the columns both for the facade columns and the core columns.

This drawing breaks out the floor system steel framing, load transfer, etc and shows how the corner areas transfer 75 percent of their load to the perimeter. And he goes on to say the 'corner' area rests on 4 load points like a chair, which is true. It was a simple example of how the loading changes from zone to zone, nothing more.
(see 3)
Load Distribution by Floor Area

Maybe this version of yours could be called the Assisted Collapse Theory.

However, did gravity pulverize and eject the material we see flowing and billowing outward in a particle slurry? There must be a mechanism for that. Gravity did not blow out the lobby before the collapse. Gravity did not have the energy to atomize the contents of the floors.

Even if every floor system fastener was cut instantly by magic and the floors did collapse around the core, the core would have withstood. There's no way in this world it would have crumbled like tin foil even at 1/100th the speed of gravity.

What we see with our own eyes, are the contents of the floors pulverized and blown outside of the building perimeter. Its false to say that material ends up in the hole when you can plainly see your own eyes it did not.

After the dust settled, a good part of steel framing of the core remained intact, at least two floors above grade, if not three. We can see it in the photos. Core columns, still standing in a dense patch. Its in the background of the famous photo of column cut on the angle. So what pile-driver failed to crush those columns, but succeeded to crush 1,000 feet of columns above? The rest of the 100 floors of core lay around them like dropped pickup sticks. Underneath, chemical fires burned for months.

Its my opinion, whoever engineered this destruction treated it like a demolition. It was designed to achieve the maximum benefit. One of the most hazardous elements, like the asbestos used in the 'light-weight' floor pour, 220 acres of it, 4" thick, was atomized and blown to the wind. Most of the heavy gauge steel was dropped in a concentrated pile in the center and relatively clean of debris, and pre-cut into manageable lengths. Overall it was an incredibly well done job, if your aim was to reduce hazards and cut removal costs. Of course these benefits might be just acts of God, but i rather doubt it. I see them as willful acts of evil men performing efficiently.