Merged New video! Architects and Engineers - Solving the Mystery of Building 7

[alienentity]

GB, you can compute what will happen to a structure when you tip it if you analyze it as a bridge. I did a basic analysis for the twin towers, and they utterly lacked the strength to be able to be laid on their sides without collapse. Very few buildings in fact can be tipped without disintegration. They are designed such that the major force is always in a single direction, and depend on compression and gravity to hold together. And for that they depend on substantial vertical alignment.

Go past a certain point and they have no strength left and the disarticulated segments just free fall. We clearly see that in the twin towers, too.

WTC-7 was a bit different, but what happened is that the heat from the unfought fires expanded truss members until they pushed key bits out of that substantial vertical alignment and it fell from the inside out.

That's a really nice, concise explanation of the failure to tip. Thank you.

 

[Grizzly Bear]

GB, you can compute what will happen to a structure when you tip it if you analyze it as a bridge. I did a basic analysis for the twin towers, and they utterly lacked the strength to be able to be laid on their sides without collapse. Very few buildings in fact can be tipped without disintegration. They are designed such that the major force is always in a single direction, and depend on compression and gravity to hold together. And for that they depend on substantial vertical alignment.
Go past a certain point and they have no strength left and the disarticulated segments just free fall. We clearly see that in the twin towers, too.

WTC-7 was a bit different, but what happened is that the heat from the unfought fires expanded truss members until they pushed key bits out of that substantial vertical alignment and it fell from the inside out.

Correct...
I was asking for him to "demonstrate" whether he knew anything about what would happen. I'm leaning, even with the answer you just gave being correct, the concept will fly over his head... but then that's more or less the point.

The problem is, conspiracy believers like to simplify structural mechanics like it's a pre-k topic, in other words what they "think" engineering and design is, runs contrary to reality.

 

[Zeuzzz]

expanded truss members until they pushed key bits out of that substantial vertical alignment

Can you define "key bits" in regard to the NIST report so i can try to find it?

Isn't it unlikely that anything from the load bearding columns would be significantly pushed when they are the main supports for the building, the main force from thermal expansion of trusses I would have thought would push outwards from the main support columns, using their structural strength to expand into more external areas with less structural strength.

 

[MIKILLINI]

Damage usually only proceeds in one direction, the path of least resistance. That is not what happened in WTC7(or the towers). The failure of one steel support column caused every other steel support column to fail within 30 seconds? That interpretation is like an event in a Saturday morning cartoon.

Of course you have an interpretation that has no evidence to back it up. Research is a procedure that has great value in gathering evidence to validate a theory. It's very evident that your time has been spent with conspiracy sites and Saturday morning cartoons.

 

[Animal]

Can you define "key bits" in regard to the NIST report so i can try to find it?

Isn't it unlikely that anything from the load bearding columns would be significantly pushed when they are the main supports for the building, the main force from thermal expansion of trusses I would have thought would push outwards from the main support columns, using their structural strength to expand into more external areas with less structural strength.

What you "think" is meaningless.

Floor trusses (or beams) span "typically" from structural bay to structural bay. Their loads are transferred to girder trusses (or beams)which typically run from column to column. The girder trusses loads are transferred to the columns and transmitted downward, either to the ground or transfer beams and girders. The floor trusses and girder trusses (or beams) also provide lateral support to the building columns.

When the floor trusses were heated, they expanded, creating a horizontal force on the girder trusses (or beams) that they were not designed to carry. Those failed horizontally at the connections to the columns (the weakest point of the assembly) With those connections failed, the columns no long had the lateral support they required in order not to buckle from the loads they were carrying from above. The columns failed, and started the chain of events that caused the entire structure to fall

The exterior of the building would have been design to resist more horizontal forces due to wind load.

 

[Zeuzzz]

Floor trusses (or beams) span "typically" from structural bay to structural bay. Their loads are transferred to girder trusses (or beams)which typically run from column to column. The girder trusses loads are transferred to the columns and transmitted downward, either to the ground or transfer beams and girders. The floor trusses and girder trusses (or beams) also provide lateral support to the building columns.

When the floor trusses were heated, they expanded, creating a horizontal force on the girder trusses (or beams) that they were not designed to carry. Those failed horizontally at the connections to the columns (the weakest point of the assembly) With those connections failed, the columns no long had the lateral support they required in order not to buckle from the loads they were carrying from above. The columns failed, and started the chain of events that caused the entire structure to fall

The exterior of the building would have been design to resist more horizontal forces due to wind load.

Thanks.

 

[sylvan8798]

The exterior of the building would have been design to resist more horizontal forces due to wind load.

This can be seen from the fact that some of the exterior moment frames were left partially intact after the collapse. Truthers see it as suspicious that the exterior seemed to fall kind of all together, but if you look at those frames, they did exactly what they were designed to do.

I understand what Zeuzzz is trying to say (I think), and in a more conventional rectangular grid of framing it might have worked, but WTC 7 had an unusual situation with some of the framing, and that complexity could have contributed to the complexity of the collapse.

Zeuzzz, the upshot here is that a group of people with many more years of education and experience than you or I (and I was a structural engineer for 7 years) took a long time to "solve the mystery of building 7". Truthers want you to believe that you can just figure it out from looking at a video and using your common sense. You and I can understand NIST's conclusions, but probably not without putting in more effort than the average truther wants us to.

 

[Clayton Moore]

Thanks.

That was a sublime response.

 

[Animal]

This can be seen from the fact that some of the exterior moment frames were left partially intact after the collapse. Truthers see it as suspicious that the exterior seemed to fall kind of all together, but if you look at those frames, they did exactly what they were designed to do.

I understand what Zeuzzz is trying to say (I think), and in a more conventional rectangular grid of framing it might have worked, but WTC 7 had an unusual situation with some of the framing, and that complexity could have contributed to the complexity of the collapse.

Zeuzzz, the upshot here is that a group of people with many more years of education and experience than you or I (and I was a structural engineer for 7 years) took a long time to "solve the mystery of building 7". Truthers want you to believe that you can just figure it out from looking at a video and using your common sense. You and I can understand NIST's conclusions, but probably not without putting in more effort than the average truther wants us to.

Just to follow up a little more. The fact that the girder truss (or beam) at Col 79 only supported floor trusses on one side meant that it was not restrained (except possibly for the shear studs) in the direction that the floor trusses were expanding. If the floor trusses on the opposite side been running in the same direction (instead of parallel) the building may have survived.

 

[Cl1mh4224rd]

Damage usually only proceeds in one direction, the path of least resistance.

You know we can cut steel with water, right? Common sense says that "the path of least resistance" is not through the steel, though, so how can this possibly be? Is it possible that "the path of least resistance" is not a major factor in all situations?

Actually, someone here once reworded the concept as "the path of least energy change", which I think makes more sense. Would it take less energy to deflect the high-velocity water off the surface of the steel, or to just cut right through it? We already know the answer...

 

[cantonear1968]

No you are skeptic, when you defend your OWN THEORIES WITH FACTS AND EVIDENCEofficial story against skeptic people uhh i mean truthers. Who are skeptic about the official story, uhhh i mean, who are crazy conspirists.

You were so close! You started the sentence correctly, but then lost it in the end!

 

[Marokkaan]

You were so close! You started the sentence correctly, but then lost it in the end!

So for example: computer simulations are the facts?

What happened to the steel, where NIST has no answer about it, are the facts?

I have to think about a christian. He told me Jesus can walk on water. I said do you have proof? He said its a fact, because we can read it in the books..

 

[cantonear1968]

Damage usually only proceeds in one direction, the path of least resistance. That is not what happened in WTC7(or the towers). The failure of one steel support column caused every other steel support column to fail within 30 seconds? That interpretation is like an event in a Saturday morning cartoon.

OMG!



Did you just finish watching Loose Change?
Volume 1?

 

[LSSBB]

So for example: computer simulations are the facts?

What happened to the steel, where NIST has no answer about it, are the facts?

I have to think about a christian. He told me Jesus can walk on water. I said do you have proof? He said its a fact, because we can read it in the books..

Got you own perpetual motion machine there Marokkan? As long as you ignore all the other evidence, and concentrate soley on column 79 not being found, you can maintain your claim that a collapse due to a fire is not proven. Why does the lack of physical evidence trump all else?

 

[cantonear1968]

So for example: computer simulations are the facts?

Please read:
http://www.internationalskeptics.com/forums/showthread.php?postid=7723099#post7723099

What happened to the steel, where NIST has no answer about it, are the facts?

Examined 3 times by engineers for relevant investigatory value before being released for recycling.

I have to think about a christian. He told me Jesus can walk on water. I said do you have proof? He said its a fact, because we can read it in the books..

Are you seriously comparing the Bible to a 3 year engineering investigation conducted by 200 relevant experts in their fields, accepted by the engineering community as a whole and which has not come under any serious criticism?

Are you out of your mind?

 

[Marokkaan]

Got you own perpetual motion machine there Marokkan? As long as you ignore all the other evidence, and concentrate soley on column 79 not being found, you can maintain your claim that a collapse due to a fire is not proven. Why does the lack of physical evidence trump all else?

Whats the evidence? Tell me?

 

[Marokkaan]

Please read:
http://www.internationalskeptics.com/forums/showthread.php?postid=7723099#post7723099

IS it difficult to answer?

I saw by the way an earlier post of you with a video. The chance is really big im talking to a troll. but i will try

Examined 3 times by engineers for relevant investigatory value before being released for recycling.

NIST didnt research, do not lie. And nobody can explain what the cause is of the situation of the steel.

Are you seriously comparing the Bible to a 3 year engineering investigation conducted by 200 relevant experts in their fields, accepted by the engineering community as a whole and which has not come under any serious criticism?

Are you out of your mind?

Maybe you have to read again(i know its difficult). I was talking about your facts and evidence.

You dont have the facts and evidence of the cause of the collapse of the three towers

 

[ElMondoHummus]

You see, this is why I say that truthers know they're distorting things for the sake of argumentation but do it anyway because their goal is never to honestly uncover truth. How in God's name does someone try to make an argument that analyses are facts? That's going out of your way to be illogical. That's deliberate obsfucation that has no other purpose than to bog down a debate with irrelevancies.

Honest critiques would concentrate on potential sources for error, and the inevitable discontinuities between simulations built on observations and real world occurances, but they'd understand that material properties are indeed established and accurate, therefore uncontroversial. Dishonest critiques just try to throw wrenches in the machinery.

 

[LSSBB]

Whats the evidence? Tell me?

What's the evidence that there was a controlled demolition? Tell me that first. And since you insist on Physical Evidence, that's what we'll limit it to.

 

[cantonear1968]

IS it difficult to answer?

No. I did answer.

I saw by the way an earlier post of you with a video. The chance is really big im talking to a troll. but i will try

That's not me. And I like your irony.

NIST didnt research, do not lie.

[face palm]

And nobody can explain what the cause is of the situation of the steel.

Could you try writing that sentence more coherently?

Maybe you have to read again(i know its difficult). I was talking about your facts and evidence.

Nope. I have read enough. And for the facts and the evidence try reading the report some time. It will be very helpful to you.

You dont have the facts and evidence of the cause of the collapse of the three towers

Again, read the report.
Or please tell me what you find scientifically incorrect with their conclusions. I'm willing to listen, if only to correct your misconceptions.