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This construction type resembles the WTC Towers quite well.
And a good fire insulation proved sufficient to not cause a collapse.
The total burnout of four and a half floors did not cause damage to the main structural members due to a good application of sprayed fire protection on all steelwork. There was only minor damage to one secondary beam and a small number of floor decks
1. He is not worth calling a member as he has been banned under EVERY user name (at least 6) within days, what do you think spanned between the beams (which are not that massive they DON'T have to be)
2. Have you checked the construction of the buildings on your so called steel building fire post.
thank you for that tip i will look it up as i hearsd about it years ago
originally posted by: beijingyank
a reply to: douglas5 The best information about the Jap war booty falling into the CIA/Bankster/Oligarch/Military Industrial Complex's/Shadow Government's hands come from the book Gold Warriors by the Seagraves.
Dulles and his minions are all over this capper.
originally posted by: GenRadek
a reply to: LaBTop
Also LaBTop, was this 1st Interstate Bank building a trussed design? Cause a structural steel frame is more in tune with steel beams and columns than columns and trusses supporting floors.
I am sure you have read about One Meridian Plaza burned and what happened inside there:
Pay close attention to the steel beams supporting the floors above and what happened to them. Mind you, WTC Towers did NOT have floors built this way. They had light steel trusses that are much thinner than the beams we see at One Meridian Plaza. But look closely, if that can happen to steel beams in a fire, what do you think would have happened to the thinner trusses? Ask a firefighter if you get a chance what their views are on going into a burning building with a truss supported roof. (Hint: Never trust a truss)
Autoexposure occurred when fire lapped out of broken windows on the 22nd floor up the side of the building to the 23rd and 24th floors. Without the ability to extinguish the fire, the fire was able to spread further and further up the building.
Because the fire had consumed multiple floors and structural damage and sagging was evident, the building was feared to collapse, and all firefighting efforts on the interior were abandoned at 7:00 AM on February 24th. Efforts continued on the exterior of the building from some surrounding high-rises, but the fire was ultimately quenched when it reached the 30th floor, where a tenant had installed ten automatic sprinkler heads. These sprinkler heads alone stopped the vertical spread of fire, and it was declared under control at 3:01 PM on February 24th.
Engineers concluded that the spray-on fireproofing had in fact done its job in protecting a majority of the structural steel (Fireproofing 1991).
The columns of the building seemed unaffected by the fire and were supporting their loads without problem. However, girders and beams did sag from the heat of the fire, some as much as three feet as is shown in Figure 4.
Cracks were noticed in the concrete floors and stairwell walls
originally posted by: samkent
I think it would be fair to say the floor construction of WTC was very similar to the roof construction at your local Walmart.
Except that Your Walmart doesn't have the added weight of concrete.
The floor system comprised lightweight steel bar trusses spaced at 2.03 m centers and braced by secondary trusses spaced at 4 m.
The secondary trusses supported a profiled steel deck with 102 mm (4 in.) thick cast-in-situ lightweight concrete slab.
The top bends (or knuckles) of the diagonal truss bars extended above the top chords and were embedded into the concrete slab to make the whole system composite.
The floor system spanned between the external walls and the core. At the external walls, truss top chords were bolted to the seats welded to the spandrels. At the central core, trusses were bolted to seats welded to a girder supported by the core columns.
Viscoelastic dampers were installed between bottom chords and spandrels to reduce the sway and vibration of the buildings by winds.
The floors supported the gravity loads and provided lateral stability to the external walls.
And see my above post with its EVIDENCE that those trusses were NOT hanging in front of a row of windows in that "famous" NIST photo in their final report, where they based their whole "sagging trusses" fairy-tale on.
They were obviously sagged aluminum ceiling rims.edit on 28/8/14 by LaBTop because: (no reason given)
originally posted by: GenRadek
a reply to: LaBTop
LaBTop, look at the One Meridian Plaza fire damage again. Notice something about the horizontal beams? They too had a steel decking above them and concrete. And yet, look at how much sagging occurred including the steel decking with the concrete. Quite a bit eh? So, if these were far larger, thicker, and better attached to the vertical columns than the floor structure of the WTC, and they still managed to have such a degree of damage that it had be torn down, how can you say the trussed ones should have fared better? The sagging would be more pronounced of the trusses and the steel decking would have added MORE weight to the trusses already sagging, aggravating it.
LT : ""On February 23, 1991, at 8:23 PM, the lobby guard desk in One Meridian Plaza and the security company contracted to monitor the building were both alerted to a fire alarm on the 22nd floor. --snip-- it was declared under control at 3:01 PM on February 24th (Chubb 1991)"" GenRadek, do you realize HOW LONG those fires burned like CRAZY.? 18 hrs and 28 minutes.....WTC 1 burned ONLY 102 minutes, WTC 2 even less, ONLY 56 minutes Sprayed-on fireproofing was certified for either 1 or 1.5 hrs !
Also you forget one major factor at WTC and that was the aircraft impact. The impact knocked loose a lot of fireproofing and the fireproofing was already substandard to begin with. You mean that this would not have affected the fire safety of the structure either? All the truss needs is one spot to be affected and it will do the rest. The other fire scenarios had intact fireproofing and even superb fireproofing. WTC 1 and 2 did not. All it needed was the floors to buckle and cause the exterior columns to bend in and that did the rest. Also according to reports, there weren't any steel re-bars in the concrete pouring. The steel decking itself just had the concrete poured on.
I am 100 % sure that is wrong. I read in NIST that there were re-bars laid in the concrete, and the decks even had extra steel "hats" welded on them, to even let the concrete have a better grip on the steel deck it was poured on. I'll look it up for you.
"All the truss needs is one spot to be affected and it will do the rest." No, wrong, the whole floor was one huge PLATE, just one deformed truss or its seat would do NOTHING to that floor PLATE.
Do you have an explanation as to why we see the exterior columns bending inward prior to the collapses of both towers? What is your insight as to how this happened if there were supposedly explosives all over the place? I have yet to see explosives cause exterior columns to get pulled inside like that.
Yes, I gave that in the other thread's page 6, I just linked to for you to read my TB posts.
In short, they blew up the welds in the outer rows of 47 core columns at every third floor, since that was their full length, 3 floor heights. Cutter charges took care of that or shaped TB charges. That's why you saw my post with all the dented inwards column ends, that happens when a cutter charge is exploded horizontally besides a column-end its weld.
The columns were thus blown inwards and aside a bit and slipped down about a meter or so, taking the huge steel COMPOSITE floor plate with them down also a meter. Do the math how much the exterior columns will then be pulled inwards. It's a simple Pythagorean calculation. The denting inwards proved already that the floor plates and floor trusses and their SEATS welded and bolted to those exterior columns their Vierendeel triple columns packs, did NOT FAIL, as NIST likes us to believe.
I know I can.
Fire compartmentalization :
In the core area, the stairwells and elevator shafts were enclosed by 2 hour fire-rated walls made of gypsum wallboard on steel studs.
In the open-plan tenant area, 1 hour fire-rated floor-to-slab partitions were used to separate the tenant spaces from each other and from the common core area.
Fire stopping materials were used to fill gaps in walls and floors to prevent the spread of smoke and flames.
The external wall was connected with the floors without gaps.
Fire protection to steelwork :
Most of the core columns were protected by gypsum wallboard.
Slab trusses, perimeter columns, spandrels and some faces of core columns were coated with three different sprayed fire protection materials.
The fire-induced thermal expansion of the floor system surrounding Column 79 led to collapse of Floor 13. That in turn triggered a cascade of floor failures. In fact, there were a cascade of floor failures that led to loss of lateral support to Column 79 over nine stories, resulting, then, in the failure of Column 79 through buckling.
NIST’s claim that the collapse of WTC 7 was initiated when Girder A2001 was pushed off its seat at Column 79 is untenable.
With the alleged initiating event ruled out, all of NIST’s claims about subsequent structural failures must be considered baseless and invalid.
NOTHING is underneath that section to slow down the initiating collapse.
NIST pretty much explains in a nutshell that that little bit of acceleration comes from the fact that interior floors collapsed first before the global collapse we saw. Nothing more. Now if you could direct me to actual proof that explosives were used I'd listen. But truthers had over 10 years to come up with something, and failed.
2 months ago
Yes but you're ignoring his fundamental premise that PART of the collapse took place at freefall speed. You never even address it, which sounds like a subtle admission that David Chandler is right. This video does nothing but reiterate the AVERAGE acceleration that NIST presents, while ignoring the INSTANTANEOUS acceleration, which David Chandler correctly points out.
In short, this video is bulls_hit.