The 9/11 Forum

DoYouEverWonder wrote:What would 30 years worth of wind and salt air do to these bolts? Especially in a building that was designed to sway? Wouldn't these bolts corrode and loosen up over time?

Welcome

I'd suggest there is bound to be some amount of surface corrosion on the tower structure, but rust is pretty good as a self-insulator (Not sure how else to word that, but shout if you don't get what I mean) so I think there is a reasonable limit to how deep the rust could penetrate.

I'd also suggest that the surfaces prone to any amount of rusting would not be at points in close contact with any other point, so the, er, flat end of a bolt is going to be exposed to nothing at all....they are tightly pressed against other surfaces and so not exposed to air.

It would also be useful to know the anti-corrosion properties of all members in contact with the bolts, and any treatments they may have been subjected to.

I'd have to ask specifically what surfaces you are referring to, as there certainly wouldn't be much in the way of wind on any internally mounted bolt, nor on any of the column end-to-end bolts, whose access points were all internally facing and well shielded from even local internal air movements. Without knowing the exact bolting method off-hand (as I'm not sure what bolts you mean) I'd still suggest that even if some amount of loosening did occur, that corrosion would not be near the top of my list of causes. (I'd be inclined to suggest that a bit of corrosion would result in a tightening of the connection....if a rusty old car is anything to go by anyway Absolutely impossible to get rusty old bolts shifted)

At the end of all the checking, we have no way of knowing if in reality there was any corrosion, or any loosening. We could only estimate the potential (slight ?) reduction in energy requirements to fail them.

Are there any photographs of the bolts in question that could be helpful ?

I was wondering because until recently, I had assumed that most of the steel had been welded together but from what I understand, except for the prefabricated parts, most of the sections were only bolted together. Is this a correct assumption?

The reason why I ask is because there was another building in NYC, the Citicorp Building that was structurally similar to the WTC, where they bolted the joints instead of welding them and then later discovered that the building was in danger of collapsing under certain circumstances. In the case of the Citicorp Building they actually went back and welded steel plates over the joints.

THE FIFTY-NINE-STORY CRISIS
http://www.duke.edu/~hpgavin/ce131/citicorp1.htm

Is it possible the WTC was suffering from a similar problem? It would have been one more reason for the POB to want to get rid of these buildings.

DoYouEverWonder wrote:from what I understand, except for the prefabricated parts, most of the sections were only bolted together. Is this a correct assumption?

Many bolted assemblies were also welded. It would be erroneous to generalise.

Could you clarify what connections you are referring to ?

DoYouEverWonder wrote:I was wondering because until recently, I had assumed that most of the steel had been welded together but from what I understand, except for the prefabricated parts, most of the sections were only bolted together. Is this a correct assumption?

The reason why I ask is because there was another building in NYC, the Citicorp Building that was structurally similar to the WTC, where they bolted the joints instead of welding them and then later discovered that the building was in danger of collapsing under certain circumstances. In the case of the Citicorp Building they actually went back and welded steel plates over the joints.

THE FIFTY-NINE-STORY CRISIS
http://www.duke.edu/~hpgavin/ce131/citicorp1.htm

Is it possible the WTC was suffering from a similar problem? It would have been one more reason for the POB to want to get rid of these buildings.

If I remember correctly the difference with the Citicorp building is that the bolted design was not sufficient for the diagonal windload as it was not considered. There wasn't much of a choice afterward but to weld on additional splice plates. If the diagonal windload had been considered in the original design a bolted connection could have been designed to handle it.

DoYouEverWonder (May I call you DYEW?)


My opinion is that the best way to study your question is to look at the bolt connections themselves in the rubble.

Both prefabricated perimeter sections and core column sections were remarkably well preserved in the rubble (they suffered very little deformation in the fall and collisions). Many of the perimeter bolts remained intact even after the abuse to which they were subject in the collapse, the fall to and the collision with the earth.

Large photo collections of these prefabricated perimeter sections do exist.


A general perimeter column photo library
http://www.sharpprintinginc.com/911/index.php?module=photoalbum&PHPWS_Album_op=view&PHPWS_Album_id=12&MMN_position=102:102&MMN_position=198:198

Perimeter columns organized by location within the rubble at the second post at the following link
http://the911forum.freeforums.org/perimeter-column-layout-mappings-perimeter-damage-verified-t199.html

Many of these photos are close-ups of damaged perimeter columns as they were originally found after the collapses.

Using these, do we see signs of corrosion along spandrel plate connections or surviving bolts?

These photo collections are valuable because they allow each one of us to verify the as-is conditions of thousands of these bolts without relying on someones opinion.

I'm sorry, I don't think I explained myself well. Corrosion would have been a minor issue, if at all.

My concern is the way the perimeter wall was assembled. Yes, the prefabbed section were welded but these sections were only bolted together when the building was put together? Then it's no wonder that these wall would fall apart like a pile of lego blocks, with the help of strategically placed explosives.

However, what I'm trying to get at is that bolting these walls together was a bad idea to begin with and has in the case of the Citicorp Building was done more in the interest of economy, then safety. (The Citicorp Building wasn't designed to be bolted together, but someone issued a change order to go from welding to bolting, so who knows if they did the windload calcs when they made this change or has they found out later, that they made a major omission to begin with.) If the WTC was becoming a dangerous building because of the way it was constructed, wouldn't that be a good reason for wanting to destroy it? And wouldn't a building that was bolted together be easier to destory then one that was welded?

I'm afraid that there would not be any good economic reason for the collapse, Silverstein only renewed the insurance because he didn't want to loose that much

the final bilance would be good for him, if he would be able to win against the airlines.........

DoYouEverWonder wrote:I'm sorry, I don't think I explained myself well. Corrosion would have been a minor issue, if at all.

My concern is the way the perimeter wall was assembled. Yes, the prefabbed section were welded but these sections were only bolted together when the building was put together? Then it's no wonder that these wall would fall apart like a pile of lego blocks, with the help of strategically placed explosives.

However, what I'm trying to get at is that bolting these walls together was a bad idea to begin with and has in the case of the Citicorp Building was done more in the interest of economy, then safety. (The Citicorp Building wasn't designed to be bolted together, but someone issued a change order to go from welding to bolting, so who knows if they did the windload calcs when they made this change or has they found out later, that they made a major omission to begin with.) If the WTC was becoming a dangerous building because of the way it was constructed, wouldn't that be a good reason for wanting to destroy it? And wouldn't a building that was bolted together be easier to destory then one that was welded?

The original welded design of the splices on the chevron braces of the Citicorp building wasn't sufficient either as it did not consider the diagonal wind load. The move to the bolted design they used was based on the original wind load calculations. It was the insufficient load calculations which were predominantly to blame.

The bolted joints of the perimeter columns in the twin towers were mitigated by staggering the wall panels so that no more than every third panel had it's column splices/joints on the same story.

Welded joints would not have prevented the collapses of the perimeter walls if the floors were taken away and the corner joints of the perimeter wall were removed. The slenderness ratio would have been too great and the columns would have buckled in that situation. The mechanical floor perimeter sections did in fact have welded splices on the columns there and the collapse roared right through there also.

Fellow researcher, we know that all 47 core columns consisted of 36 ft sections (more or less).

We know that all CC connections for all 47 core columns were on the exact same elevations (they weren't "staggered").

We know that for WTC1 all CCs had connections on the 98th floor at same elevation.

We know that the WTC1 core seemed to fail from south to north, all in less than one second, along what seems to be the 98th floor.


So, you would think that researchers and the NIST would pay special attention to this "horizontal connection plane" through floor 98 to see if connection breakage, not creep buckling, could have caused WTC1 to fail so quickly through the 98th floor.





But no. I'd suggest the serious 9-11 researcher reflect on just how much they actually know about the 98th floor CC connections and why. Friends, please ask yourselves........


1) After all this time, do you know how the core columns were spliced together in the WTC1 damage zone? Why not?

2) Have you ever read anything by NIST about how the CC splices are designed in the WTC1 damage zone.

Have you ever seen a diagram of the spices? (Did you just assume they were welded?)


3) Is there anything in the NIST reports which examines CC splice strength in the WTC1 damage zone, considering that a big airplane crashed into it's side.

Anything that examines or questions 92nd, 95th or 98th floor CC splice reaction to impact damage?


4) Considering how the whole core of WTC1 seemed to fail so quickly right along the 98th floor splice connection plane, is there anything in the NIST reports about the splices?



The only literature I've ever seen on the connections is buried in some inspection reports in


http://wtc.nist.gov/pubs/NISTNCSTAR1-1C.pdf


From pg 48 of a WTC1 inspection

Core corner columns inspected from office area floors—Core corner columns were inspected at all four corners of the 92nd to 93rd floors and at three corners at the 77th to 78th floors. All seven locations were inspected by removing the five or more layers of gypsum wallboard around the splice locations, which were 3 ft 0 in. above the finished floor level.
On the 92nd to 93rd floors, all four splices were bolted connections. No defects were found at any of the bolted splices. Welded splices were found at all three locations on the 77th to 78th floors, and were tested using the dye penetrant method. Results from the tests showed that there were no surface cracks in the welds. Steel plates, bolts, and welds that were visible were found to have only light surface corrosion.

Pg 39

Core columns inspected from office area floors—Quality Assurance personnel inspected core corner columns at eight splice locations (see Table B6 in the survey report for locations). Seven of the splices were welded, and the welds were tested using the ultrasonic and magnetic particle methods. The eighth Chapter 3 Draft for Public Comment 40 NIST NCSTAR 1-1C, WTC Investigation
location was a bolted splice connection. No defects were found in any of the welded splices. Steel
columns exhibited light surface corrosion, as did the bolted splice on the bolts and splice plates.

The pg 48 quote verifies that all four corner columns on floor 92 were bolted, not welded.


There is no literature which shows that even a single CC had welded splices on the 98th floor level.

This is the only literature I am aware of which tells us about the nature of the splices in the WTC1 damage zone.

The 4 corner columns among the strongest in the core, possibly the strongest. They have bolt connections on the 92nd floor. This tells us that there is probably a horizontal plane through the 98th floor core which consists entirely of bolt connections.

There is no evidence of a single weld along the 98th floor CC connections.




When so called 9-11 "experts" estimate how many "tons of TNT" would be required to bring down WTC1, by what logic do they make these estimates?


"Experts"? Have they ever considered the nature of the 98th floor CC connections combined with the possibility of OOS runaway destruction conditions in their calculations?


What are their explosive estimates based on? (Hot air, fantasy)


"9-11 expert"= shameless liar. So much horror as a result and people pose as "experts" to dissuade further questioning?

DoYouEverWonder wrote:My concern is the way the perimeter wall was assembled. Yes, the prefabbed section were welded but these sections were only bolted together when the building was put together? Then it's no wonder that these wall would fall apart like a pile of lego blocks, with the help of strategically placed explosives.

Welcome DYEW.

In the resistance study of the structure of the towers, the exterior columns bore ONLY vertical gravity load. As they are stabilised horizontally by the trusses, they could not get force on the bolted splices.

But you are right, these columns will fall apart like a pile of lego blocks if they are not horizontally stabilized. The main horizontal stabilisty is made by the welded corecolumns and their strong braces in all directions, including in diagonal directions.

The official reports use that outer columnsand their bolted splices to prove that the towers should collapse! But for that they consider thcore columns as "useless hollow steel shaft". That's the major lie of the official reports.

mehmeti wrote:The official reports use that outer columnsand their bolted splices to prove that the towers should collapse! But for that they consider thcore columns as "useless hollow steel shaft". That's the major lie of the official reports.

I doubt multiple reports (official, or otherwise) would use the same quote.

Please be very specific, stating which report, section, page (as much detail as poss really) when making such statements.

I'm far from a fan of, say, the NIST report, but it does include detail on lateral forces upon the perimeter, and I have not seen the phrase quoted above within it, nor your stated conclusion.

there were rumours of galvanic corrosion occuring, but i think that is only bolts connecting the aluminum facade, and not the structural bolts at the ends of the columns. it's like femr2 says, any corrosion there would only tighten the connections.

rumour source, ....t.s. gordon

http://www.indybay.org/newsitems/2006/08/16/18297965.php

as an aside, i keep forgetting to bring up the viscoelastic dampers. has their strength been added to the estimate of how much it takes to fail a floor, because they had to be quite strong to be a structural component, no?

No mention of CC connection bolt problems in the available inspection reports. Some light surface corrosion on some perimeter column to column bolts. The energy required to destroy one section of OOS flooring is important to study collapse propagation rates.

The resistance of OOS floor section to being destroyed and knocked clean of column connections is a huge factor in collapse time and collapse rate. Nobody has made a good guess of their possible values yet.

.........................................

From the available literature we discovered that there is a horizontal plane on the 98th floor right through the core where all core columns naturally break in two if the connecting bolts are removed.


Every 114+ story core column is already "cut" at the 98th floor. All one need do is remove the bolt connectors and push the top part over a little.

One just has to take advantage of existing "cuts" by manipulating (removable) bolt connections.


(In WTC1 there is no reason to attack a single core column to initiate collapse. One attacks the 98th floor connections.....first with a socket set, then with exploding bolts and lastly with little tiny bombs to trigger displacement if necessary.

In thi view from the west after the slightest tilt the core gives. The core provides none of the slight "hinge".

http://www.youtube.com/watch?v=b_f3d-gETnk&feature=related

How do you get so many CCs to fail at almost the same time without large pressure ejections?

But if you remember that this would be expected to occur if the 98th floor bolts were removed the rapid lateral failure progression makes more sense.

The upper block core is "just sitting" on the lower block core if the 98th fl CC connection bolts are removed. A slight tilt, like you see in the video, and the top parts will just fall off the bottom part in rapid succession.

With removed bolts, the slight tilt serves as a trigger to displace CCs off the base on which they are resting.

femr2 wrote:

mehmeti wrote:The official reports use that outer columns and their bolted splices to prove that the towers should collapse! But for that they consider the core columns as "useless hollow steel shaft". That's the major lie of the official reports.

I doubt multiple reports (official, or otherwise) would use the same quote.

Please be very specific, stating which report, section, page (as much detail as poss really) when making such statements.

I'm far from a fan of, say, the NIST report, but it does include detail on lateral forces upon the perimeter, and I have not seen the phrase quoted above within it, nor your stated conclusion.

I never told that all reports contained that statement. Only one contains it; the commission report on chapter notes.

With that statement (they consider the core columns as "useless hollow steel shaft") I wanted to emphasis that the "main guideline" of the official reports could be summarized as "the main structure is made by the outer columns and floor trusses; the core section is useless hollow steel shaft". I like summarize things to get a global view of the facts without being lost in small details.

What actually the reports contain?
1- FEMA report shows, in their fire melting and collapse scenario, the core column identical to outer column and could buckle like an outer column.
2- NIST report gives all details about the outer columns and floor trusses, too many pictures, drawings, dimensions … But it contains no one picture of the biggest core columns (ie 501, 508, 1001, 1008 at about floor 10), there is no drawing of the splices of the core columns, …
3- NIST report places the wind forces to be bored by the outer columns! That’s wrong. The outer columns are unable to still stand alone; they’ll never bore lateral wind forces. For that purpose, it’s required to get strong diagonal connection which exists only between core columns.

How could you summarize that biased content of the official reports?

Femr, in the video can you see that flash near the south, 95th floor just a second before the 98th floor starts to move?

http://www.youtube.com/watch?v=b_f3d-gETnk&feature=related

Anything?