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P.C.
millennium club
Joined: 26 May 2004
Posts: 2163
Location: Denmark
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 Posted: Mon Sep 06, 2004 3:12 am Post subject: |
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Hi
Maby I better retype the question ;
If 40000 ton move down one inch, how much heat energy will that produce, how big a "surface" will carry that ,how much heat will show between the members that move and those that don't.
P.C.
http://home20.inet.tele.dk/h-3d/kassehus14.jpg
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tenenbaum
Joined: 26 Aug 2004
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Location: New York
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| Posted: Sun Sep 12, 2004 9:49 am Post subject: |
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A vigorous discussion about a conspiracy among officials within US took place at http://portland.indymedia.org/en/2004/09/296788.shtml. There must be reasons for such a theory indicating a strong resentment against the officials here, and what they represent. Prejudice is really very sad.
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tenenbaum
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tenenbaum
Joined: 26 Aug 2004
Posts: 175
Location: New York
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| Posted: Fri Oct 22, 2004 5:00 pm Post subject: |
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The New York Times 10/20/04 article "Study Suggests Design Flaws Didn't Doom Towers" at http://www.nytimes.com/ads/carrotink/CarrotInkApril28.html should be actually read "Study Suggests [Incorrectly] Design Flaws Didn't Doom Towers", because of its following quotes:
| Quote: | | The findings by the institute, however, still do not exonerate Mr. Robertson or the building's owner, the Port Authority of New York and New Jersey, which, [...] boasted that the design was so robust that the towers could be hit by a jet traveling at 600 miles per hour without collapsing or endangering the lives of occupants beyond the impact zone. In retrospect, such a claim was unjustified because the engineers had failed to consider the added stresses caused by the resulting fires. |
| Quote: | | The tentative conclusions by the federal investigators conflict with an earlier report by a team of structural engineers organized by the Federal Emergency Management Agency, who had asserted that the collapse of the north tower started in the core, not in the outer columns. |
| Quote: | | But James G. Quintiere, a professor of fire protection engineering at University of Maryland, said he questioned the tentative conclusions, as his analysis showed that in the fires created by the impact, the lightweight floors rose to a temperature high enough to make them separate from the exterior columns. "They have not presented enough evidence," he said. |
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tenenbaum
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Location: New York
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tenenbaum
Joined: 26 Aug 2004
Posts: 175
Location: New York
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tenenbaum
Joined: 26 Aug 2004
Posts: 175
Location: New York
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| Posted: Sun Jan 09, 2005 1:38 am Post subject: |
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FEMA actually provided the right explanation of cause of the WTC collapse in its Study’s Appendix B on pp. B7-B8 quoted below. It is a masterpiece of deception, because the explanation is quite unnoticeable (especially without missing words added by myself in the brackets), while the front conclusion - criticized in the article above - is obviously unreasonable even for a child.
So - on one hand - FEMA sneaked the right explanation (which directly points at faulty design, because 56 or 103 min. fire should not have disjointed and caused buckling of external columns) nobody wants to see officially, and only a few can understand, so FEMA cannot be blamed for incompetence, and - on the other hand - the FEMA’s unreasonable front explanation does not blame the structural designer for providing the unacceptable design nor the Port Authority of NY & NJ for approving such a design and issuing the building permit to construct the faulty WTC towers, so frontally FEMA does blame anyone home.
| Quote: | | As the columns lose lateral support [because fire causes column-floor connections to break off] and deform out-of-plane [or buckle] from overloading eccentricities [or shift off center of load, because by loosing one floor connection a column doubles its unsupported height quadrupling its whippness resulting in bending by the same load pressing more supple column now much easier to bend being less stiff after loosing one floor connection] and from the thermal effects [of fire], the bending moment acting on the column splice [end plate connection] does not introduce significant forces into the bolted end plate connection until the eccentricity exceeds 2 inches. As the eccentricity increases [from thermal effects], the applied bending moment will exceed the bolt preload stress when the eccentricity reaches approximately 4 inches. Continued deformation will exceed the ultimate moment capacity of the connection and result in instability as the eccentricity approaches 4.5 inches. It also should be noted that the column splices were staggered mid-height at each floor, as was illustrated in Chapter 2. As a result, two-thirds of the perimeter columns were continuous at each floor's mid-height elevation. This resulted in staggered failure patterns, as the bolted end plate connections and spandrel beam connections failed during the resulting instability and collapse. |
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Eugene Tenenbaum |
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tenenbaum
Joined: 26 Aug 2004
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Location: New York
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| Posted: Mon Jan 10, 2005 5:10 pm Post subject: |
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Correction: So - on one hand - FEMA sneaked the right explanation (nobody wants to see officially, and only a few can understand, but FEMA cannot be blamed for incompetence), which directly points at faulty design, because 56 or 103 min. fire should not have disjointed external columns nor caused their buckling. On the other hand - the FEMA’s unreasonable front explanation does not blame the structural designer for providing the unacceptable design nor the Port Authority of NY & NJ for approving such the design and issuing Building Permits to construct the faulty WTC towers, so frontally FEMA does NOT blame anyone at home for the WTC tower collapse.
| Quote: | | As the columns lose lateral support [because fire causes column-floor connections to break off] and deform out-of-plane [or buckle] from overloading eccentricities [or shift off center of load, because by loosing one floor connection a column doubles its unsupported height quadrupling its whippness resulting in bending by the same load pressing more supple column now much easier to bend being less stiff after loosing one floor connection] and from the thermal effects [of the floor heated by fire, and not the fire itself, because the external columns had been cooled by the outside chilly air from three of their four sides], the bending moment acting on the column splice [end plate connection] does not introduce significant forces into the bolted end plate connection until the eccentricity exceeds 2 inches. As the eccentricity increases [from the thermal effects, and along progressing buckling], the applied bending moment [stress deriving from buckling] will exceed the bolt preload [or pulling] stress when the eccentricity reaches approximately 4 inches. Continued deformation will exceed the ultimate moment capacity [or strength] of the connection and result in instability [or break, failure] as the eccentricity approaches 4.5 inches. |
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tenenbaum
Joined: 26 Aug 2004
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| Posted: Thu Mar 03, 2005 12:26 pm Post subject: |
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WTC 2 collapsed twice as fast as WTC 1 not because of a greater structural damage – as FEMA claimed – but because of thermal effects of floor heated by fire causing structural disintegration and progressive, destructive (non-elastic) wobbling of the towers’ parts above the impacts.
Wobbling of the WTC 2 part above the impact - twice as high as in WTC 1 (WTC 2 was hit twice as low from the roof as WTC 1) - required a half of amplitude (angle) to shift roof sideways by the same distance (overloading eccentricity), and to break it.
It actually is visible on a PowerPoint slide show made of every 12th frame of 368 frames (12.3 sec. at 30 frames/sec) of the collapse starting at 35:05 of the “WORLD TRADE CENTER Anatomy of Collapse” (by TLC and available on DVD) extracted using PowerDVD.
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Donald
Joined: 16 Apr 2004
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| Posted: Thu Mar 03, 2005 1:16 pm Post subject: |
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| Quote: | | FEMA does NOT blame anyone at home for the WTC tower collapse |
After such a lengthy dissertation, thank you for clearing this point up for us. 
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tenenbaum
Joined: 26 Aug 2004
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Location: New York
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| Posted: Thu Mar 03, 2005 3:39 pm Post subject: |
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Donald,
Do you thing that FEMA does a favor to the taxpayers (financing FEMA) not investigating domestic aspects of the WTC collapse, after they were requested to do it all at taxpayers’ expense, please? In other words, do you think that FEMA has a right to avoid certain aspects of that investigation, because of, e.g. political or any other objectives, and at the same time maybe protecting the Port Authority of NY & NJ and the structural engineers from maybe even criminal responsibility, because of that objective, e.g. to stronger blame Bin Laden, please? Do you really think that finding faulty WTC design would exonerate anyone of anything in any degree, e.g. Bin Laden, please?
Do you really think that it should be kept quiet the death of 343 firefighters, 60 police in the unsafe WTC towers caused by negligence (possibly even criminal) and maybe even conspiracy to neglect in verifying and making design to be safe by the Port Authority of NY & NJ (outside of city safety codes) and the structural engineers - thus contributing to the WTC collapse, because they wanted to make a few bucks (keep their jobs), but they did not want to or could not put a sufficient effort to earn them honestly, please?
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tenenbaum
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Posts: 175
Location: New York
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| Posted: Sun Mar 06, 2005 12:23 am Post subject: |
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A clever WASP civil engineer brought two Chinese partners (arch. and structural) expanding his office to a minority architectural-engineering firm in NYC area. Subsequently - fulfilling requirements of affirmative action - the office got large NY State projects trough FDC (Facilities Development Corp. – NYS agency dissolved, because of corruption). Only a few employees were able to measure up to necessary requirements in the architectural dept. All of them were very overworked white males. Most of the rest had a kind of good time. After working 160 hours (twice overnight) during one two-week period, I refused to work excessive overtime, i.e. more than 60 hrs, and then 50 hrs a week.
During planning a permanent departure from the office very close to the end of a big project, while doing entirely new assignment to add a final touch to elevators, and checking existing conditions (obviously doubting reliability of work of others in this office) I discovered that the actual basement level is 2 feet lower than in this $40 M project rendering all stairs 2 feet too short. But stairs, when extending down, require also more horizontal space to continue forward, but there was no room to extend them forward. So, the arch. partner decided to increase the height of stair tread above allowed by the building code causing – of course – a messy and huge change order (main tool of corruption) greatly benefiting a future contractor on expense of NYS. If he had ask me to stay in the firm for a week longer, I would have fixed the drawings before the final submission, but he had chosen not to fix them, only to violate the building code. The project was full of other mistakes and quite badly designed.
Similarly, affirmative action might have played a role in designing WTC, and might have contributed to its collapse, but it does not mean that all beneficiary of affirmative action have lacked professional qualifications.
Once after 11:00 p.m. in this office, when I was so tired that not able to do anything, but skimming through project pages, suddenly, there was a movement on structural pages of typical floors, where beam location should have been identical not resulting in a movement while skimming. On two floors some beams were designed twice as week as typical despite a typical load. It could not have been an accident, because the easiest design was to not do any changes to the typical design, but someone took the effort to weaken the design maybe to cause a change order.
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