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Post by feelfree222 on Mar 10, 2007 2:20:14 GMT -4
From the same source you linked to. I hope you are not trying to compare that weak and outer steel structure of The Windsor Building with the massive steel structure of both WTCs....do you? The Twin Towers and Building 7 were both 100% steel-framed, with large wide-flange columns and box columns, some measuring over four feet wide and fabricated of steel up to five inches thick. Severe fires in other skyscrapers which, like the WTC Towers, were 100% steel-framed, have not produced even partial collapses. For example 911research.wtc7.net/wtc/analysis/compare/fires.htmlIn contrast to the WTC Towers, the Windsor building was framed primarily in steel-reinforced concrete, with columns of concrete reinforced by thin sections of rebar. The concrete pillars in the Windsor building are clearly visible in the photographs showing the intact core exposed by the collapsed facade. The very light construction of the perimeter, described below, makes it clear that the core was the main load-bearing component of the building. Full text and detailed explanations 911research.wtc7.net/wtc/analysis/compare/windsor.html#details
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Post by scooter on Mar 10, 2007 9:15:38 GMT -4
Feelfree, you go on about how the beams measured "up to" xxx feet wide, and were "as thick as" xx inches. The impacts and fires occurred high on the structures, where the structure would be necessarily thinner and lighter. The entire towers were not built of such thick heavy beams. Additionally, the towers were over 100 stories tall, and while the fires were the ultimate cause of the collapse, the very high speed impact of massive jetliners was an undenyable contributing factor. Each impact/damage zone literally had what equated to a very large skyscraper resting atop it, over 20 stories of acre sized building. That is a bunch of load for the damaged section to absorb, complicated by the ongoing, and growing, heavy fires in the buildings.
Yes, the WTC collapses were unique, so were the very buildings themselves, and the extraordinary events of that day. To say that no other skyscraper has collapsed "from fire" is both misleading and an inappropriate "apples and oranges" argument. Until you can present a similarly sized and constructed building that underwent similar damage events and fires, the argument is pointless...and hardly "evidence" of a massive government conspiracy.
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Post by echnaton on Mar 10, 2007 10:44:24 GMT -4
Isn’t it nice to live in a land of hope. Where all steel buildings are identical because one design fits all uses and is completely fire and crash proof. Where all pieces are interchangeable. Where only a massive number of specifically placed explosives can do significant damage.
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Post by feelfree222 on Mar 10, 2007 16:09:35 GMT -4
Feelfree, you go on about how the beams measured "up to" xxx feet wide, and were "as thick as" xx inches. The impacts and fires occurred high on the structures, where the structure would be necessarily thinner and lighter. The entire towers were not built of such thick heavy beams. Additionally, the towers were over 100 stories tall, and while the fires were the ultimate cause of the collapse, the very high speed impact of massive jetliners was an undenyable contributing factor. Each impact/damage zone literally had what equated to a very large skyscraper resting atop it, over 20 stories of acre sized building. That is a bunch of load for the damaged section to absorb, Of course Which lasted only about 45 minutes .... everything below the impact aera down to the ground was intact and not affected by fire. So all of the NIST theory is based that the weldings whose fixed the supports of the floor to the stell columns were so resistant that and I cite PhantomWolf (post 23 page 2) citing the official theory: "With the moving debris of the top of the tower smashing into the floor, it would have placed that entire load onto the truss mounts causing them to buckle and give way, something that was noted in the debris (and lead to original ideas of the truss mounts softening and the floors giving way then.) The outer columns deprived of their support and with debris crashing into them then simply peeled outwards like a banana. The lower columns were just pushed out of the collapse by the falling debris, they weren't bent and failed. He makes the same mistake as the majority of CTs, that the load was falling onto the columns, it wasn't, it was falling onto the floor whose only supporting structure were four steel mounts, two on the exterior walls, and two on the core. (some actually had two on the exterior and two on other trusses!) The joins in the columns, which were only tack welded and bolted, snapped as the pressure come onto them and they where thrown from the collapse zone ...." The problem with that theory is as pointed by Rice “The subsequent 2006 repackaged documentary Building on Ground Zero explained that the connectors held, but that the columns failed, which is also unlikely.” My interpretation of Rice claim .-Because NIST assume without proving it that the weldings whose fixed the connectors to the steel columns have not broken under the weight and pressure of the broken floors debris falling onto the floor they support. The Floors The Structural System of the Twin Towers 911research.wtc7.net/wtc/arch/floors.htmlAnd remember the Twin Towers were disigned to resist lateral load pressure,effectively they were disigned to resist hurricane force winds. 911research.wtc7.net/wtc/arch/perimeter.htmlThe towers' perimeter walls comprised dense grids of vertical steel columns and horizontal spandrel plates. These, along with the core structures, supported the towers. In addition to supporting gravity loads, the perimeter walls stiffened the Towers against lateral loads, particularly those due to winds. The fact that these structures were on the exterior of the Towers made them particularly efficient at carrying lateral loads. edited to fix quote
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Post by nomuse on Mar 10, 2007 22:05:07 GMT -4
Let's back up a little here. You have been singing the praises of William Rice, who claimed "However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire. "
In the case of the Windsor building the parts that were of steel-frame construction collapsed. It does no good to say that it is unlike the World Trade Center towers in construction; you might as well say it didn't look like the Eiffel Tower! The phrase Rice uses is "Structural steel framed building," not "Structural steel framed building of columns of at least four inches in thickness" or "structural steel framed building with extensive lateral bracing."
The only wriggle room here is that the rest of the Windsor building -- those parts that were of steel-reinforced concrete -- survived and thus it can not be said that the building "collapsed."
For the latter reason, the Windsor building does not make Rice's statement into a lie. It does, however, make it very selective. Only a man with no background in the subject, or a man who had an agenda he was willing to omit facts and distort reality to support, would state that the Windsor fire had nothing to teach us about the 9-11 fires.
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Post by feelfree222 on Mar 11, 2007 0:44:08 GMT -4
Probably you should find a better example of steel framed structure than that if ou want convince someone. The outer walls consisted of steel box columns arranged on 1.8 meter centers and connected by narrow spandrel plates. The columns had square cross-sections 120mm on a side, and were fabricated of C-sections 7mm thick welded together. (these were a fraction of the dimensions, and spaced about twice as far apart as the perimeter columns of the Twin Towers.) The perimeter columns lacked fireproofing throughout the upper third of the Windsor building. And remember even that weak steel framed structure collapsed progressively. The Windsor Building fire demonstrates that a huge building-consuming fire, after burning for many hours can produce the collapse of parts of the building with weak steel supports lacking fire protection. It also shows that the collapse events that do occur are gradual and partial. Estimated time frame of collapsesTime Collapse Situation 1:29 East face of the 21st floor collapsed 1:37 South middle section of several floors above the 21st floor gradually collapsed 1:50 Parts of floor slab with curtain walls collapsed 2:02 Parts of floor slab with curtain walls collapsed 2:11 Parts of floor slab with curtain walls collapsed 2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor 2:17 Parts of floor slab with curtain walls collapsed 2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed 2:51 Southeast corner of about 18th ~ 20th floors collapsed 3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor 3:48 Fire flame spurted out below the Upper Technical Floor 4:17 Debris on the Upper Technical Floor fell down Yes you have a good case of progressive collapse. And the complete Rice claim before YOU have distort it is... "If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength.However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire."No "distorsion" of the facts as you can see here: 911research.wtc7.net/wtc/analysis/compare/fires.html
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Post by nomuse on Mar 11, 2007 5:57:26 GMT -4
He's wrong. The source of the damage to a structure does not determine the failure mode of the structure!
When you are talking a tall, thin, basically hollow structure, the failure you get is not progressive but catastrophic. It's built into the very nature of a column. Look. Get an empty roll of toilet paper. Put weight on top of it. As long as you weight it slowly and evenly it can support an amazing amount of weight; sometimes upwards of fifty pounds. Now, with this weight still on top, press lightly on one side to "kink" it. That is what happens to a tower-like structure under compressive load. Once those weight-bearing members are out of true they cease to be strong compressive members and turn into extremely weak flexion members. Collapse is not at all gradual.
This isn't engineering. Your average house carpenter knows this. If Rice thinks a steel-framed tower will settle slowly like a cube of butter in a frying pan he is either the poorest student ever, or he is hoping his audience are all idiots (and perhaps they are blinded enough by their own prejudice and preconception to be so.)
Oh, and by the way...Rice didn't say "...progressive collapse..." He said "...collapse..." So he doesn't dodge the Windsor bullet regardless of how long it took or in how many pieces it fell.
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Post by feelfree222 on Mar 11, 2007 23:34:38 GMT -4
He's wrong. The source of the damage to a structure does not determine the failure mode of the structure! When you are talking a tall, thin, basically hollow structure, the failure you get is not progressive but catastrophic. It's built into the very nature of a column. Look. Get an empty roll of toilet paper. Put weight on top of it. As long as you weight it slowly and evenly it can support an amazing amount of weight; sometimes upwards of fifty pounds. Now, with this weight still on top, press lightly on one side to "kink" it. That is what happens to a tower-like structure under compressive load. Once those weight-bearing members are out of true they cease to be strong compressive members and turn into extremely weak flexion members. Collapse is not at all gradual. ...... This isn't engineering. Your average house carpenter knows this. If Rice thinks a steel-framed tower will settle slowly like a cube of butter in a frying pan he is either the poorest student ever, or he is hoping his audience are all idiots (and perhaps they are blinded enough by their own prejudice and preconception to be so.) Interesting.... I understand the example you try to make but by chance you are not working for Fema or Nist. Get an empty roll of toilet paper. Put weight on top of it.Ho! i like that "brilliant" "example of a structure".... Replace the empty roll of toilet paper by a metallic rod of the same size -cross braced with other metallic rods -ie(a structure) and see what happen. (enjoy the insults section) This isn't engineering. Your average house carpenter knows this. If Rice thinks a steel-framed tower will settle slowly like a cube of butter in a frying pan he is either the poorest student ever, or he is hoping his audience are all idiots (and perhaps they are blinded enough by their own prejudice and preconception to be so.) Note: and that is you who call other idiots ? . Oh, and by the way...Rice didn't say "...progressive collapse..." He said "...collapse..." So he doesn't dodge the Windsor bullet regardless of how long it took or in how many pieces it fell. ] "If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength.Sound like a progressive collapse....
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Post by Data Cable on Mar 12, 2007 1:19:31 GMT -4
"If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength.Sound like a progressive collapse.... And nothing has changed since the last of the 3 or 4 billion times you've quoted this line. He's still just making an assertion, that all steel-framed structures which collapse because of fire will do so slowly. Immediately following this, he made another assertion: In the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire.
An assertion which you yourself have conceded he was wrong about. This, I believe, is the proverbial bullet to which nomuse referred. Rice authoritatively made one assertion which you agree is false. Why is this one any more reliable?
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Post by feelfree222 on Mar 12, 2007 1:29:01 GMT -4
Why is this one any more reliable? Beacause it is verifiable. see post: reply 80
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Post by Data Cable on Mar 12, 2007 1:40:03 GMT -4
Beacause it is verifiable. One event is not verification of a claim regarding the behavior of all such events.
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Post by feelfree222 on Mar 12, 2007 1:44:39 GMT -4
Beacause it is verifiable. One event is not verification of a claim regarding the behavior of all such events. That is the demonstration that shuch events are rare. ;D
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Post by Data Cable on Mar 12, 2007 4:09:59 GMT -4
That is the demonstration that shuch events are rare. Rice made no mention of rarity, he made a blanket assertion about all structural steel collapses from fire. One event does not confirm such an assertion.
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Post by nomuse on Mar 12, 2007 16:39:55 GMT -4
And I believe he is wrong about his implications of the timeline of the Windsor Building collapse. He uses the fact that not all of the structure collapsed at the same time as support for his assertion that a large steel-framed building will collapsed slowly (again, I have to ask WHERE this guy studied. There are painfully few large-scale structures that are capable of collapsing like an ice-cream treat on a hot day. Very few can support themselves in anything other than designed alignment).
In any case, he is wrong to derive one from the other. A row of dominoes can be said to collapse progressively, yet every single domino remains a rigid object and its personal collapse is sudden and immediate.
My guess (without looking at any diagrams or other descriptions), is that is what, largely, happened in the Windsor Building. Elements (sections, trusses, floors; something like that) that were capable of being treated individually "peeled off" and collapsed as each, individually, reached their buckling point. The facade did not slowly ooze off the surface of the building and slump to the ground in one big glob like a cream pie sliding off the face of a comedian!
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Post by frenat on Mar 12, 2007 17:34:13 GMT -4
Doesn't the speed of a collapse of a steel structure depend some on how much weight that steel structure is supporting? If low, I can see it failing slowly in different places over a period of time. If high, like the WTC, I see it more of weakening until it can no longer support the large weight above it and that weight falling. The falling weight then causes the failure of the rest of the structure.
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