1200 Architects And Engineers

Originally posted by psikeyhackr

Originally posted by ANOK
From what I've read the inner structure held about 80% of the weight and the outer mesh columns were designed mostly to allow lateral movement. The central columns were a lot larger, and cross braced, than the outer mesh columns.

I haven't seen many places that mention the load proportion between the core and the perimeter columns.

But there is a place in the NCSTAR1 report that says at basement level six the proportion is 53% to 47%.

I don't remember which is which so I usually just say 50-50.

psik

You know I looked for that info and couldn't find it. I swear a few years ago that information was available.

You say at basement level. That is not going to be the same as the upper floors.

Anyway as I understand it is possible that at the sixth level it was 50%-50%, 1:1, simply because at the lower levels the outer mesh doesn't bend as much as at higher levels. For example the ratio at the top floor might be 90%-10%, and the first floor 1:1. The 80%-30% would be the average overall ratio. The ratios are just guesses and I could be wrong, but I am sure at the basement level it's not going to be the same as the upper floors.

It wouldn't make sense to be 1:1 anyway because the outer mesh moves more than the inner core and that puts pressure on the core, so it would have to be able to hold more weight than the outer mesh.

Originally posted by ANOK
You know I looked for that info and couldn't find it. I swear a few years ago that information was available.

This is from NCSTAR1-2A:

The analysis reported in this section used the gravity and wind loads used in the original design of the towers, as explained in Chapter 4. The results of the analysis indicated that for the dead and live loads used in the original WTC design, the core columns and the exterior walls carried approximately 53 percent and 47 percent, respectively, of the total gravity load at the basement (B6) level.

psik

Originally posted by psikeyhackr

Originally posted by ANOK
You know I looked for that info and couldn't find it. I swear a few years ago that information was available.

This is from NCSTAR1-2A:

The analysis reported in this section used the gravity and wind loads used in the original design of the towers, as explained in Chapter 4. The results of the analysis indicated that for the dead and live loads used in the original WTC design, the core columns and the exterior walls carried approximately 53 percent and 47 percent, respectively, of the total gravity load at the basement (B6) level.

psik

Hmmm that's not what I meant. I meant the 80-30 ratio and more detail about the way it worked. All that mentions is the basement level as you pointed out, but that is not what it's going to be on the above ground floors.

I have a bunch of bookmarks about the WTC from over the years and over half of them are now dead links.

reply to post by ANOK


Sure it's strong, but it is not going to hold a third of the great pyramid of Giza. Buildings are made to hold people plus their own weight. it is not cost effective to beyond that. This is simple economics. A company is not going to waste money on a building making it support many times its own weight. They are going to make it cheap and make it object oriented in design. Why would you not cut your cost down to a fraction of their worth building according to its purpose. Form follows function. New York has no Earthquakes, not big risks, and a history of good conditions. Not much need for redundancy in structure nor strength. hence the popularity of that style here as of late.

reply to post by Azp420


That's not what I was saying. I was talking about under it, not the item itself that fell. Please do not twist. Go back to the video I posted and stop drawing straws.

Originally posted by ANOK
Anyway as I understand it is possible that at the sixth level it was 50%-50%, 1:1, simply because at the lower levels the outer mesh doesn't bend as much as at higher levels. For example the ratio at the top floor might be 90%-10%, and the first floor 1:1. The 80%-30% would be the average overall ratio. The ratios are just guesses and I could be wrong, but I am sure at the basement level it's not going to be the same as the upper floors.

I don't understand this. 80% + 30% would be 110%

The total has to be 100.

Theoretically it could be 70 -30 or 80 - 20 but not 80 - 30.

psik

reply to post by Gorman91

That's not what I was saying. I was talking about under it, not the item itself that fell. Please do not twist. Go back to the video I posted and stop drawing straws.

During the entire discussion I've been having with you we've been talking about the top section, but ok.

So you're saying the top section stayed more or less in one piece?

I ask you again, what were the upwards and downwards forces acting on the top section as it impacted the undamaged lower structure (after accelerating through the undamaged initiation zone)? Or is the key to believing your theory ignoring this?

Originally posted by psikeyhackr
I don't understand this. 80% + 30% would be 110%

LOL you got me, I'm no math major. Even though I said my figures were not accurate I should have spotted that.
So it was probably 80-20, or 70-30.

I just don't think it was 50-50, as it makes no mechanical sense, I'm sure the central core took the majority of the vertical load and the outer mesh controlled the lateral movement.

Originally posted by Gorman91
reply to post by ANOK

 

Sure it's strong, but it is not going to hold a third of the great pyramid of Giza. Buildings are made to hold people plus their own weight.

Point is your are making claims from opinion, not the research you claimed.

What is the point of this argument anyway, there was no extra weight added to the building, except the planes and they wouldn't be a problem.

"Buildings are made to hold people plus their own weight."

And what are those people who work in those building supposed to sit on...the floor? How about the office supplies, machinery, water and all of the other numerous items which are housed within in a commercial structure?

"New York has no Earthquakes, not big risks, and a history of good conditions. Not much need for redundancy in structure nor strength. hence the popularity of that style here as of late."

You may be surprised to find out that New York City is the windiest "big" city in the United States?

www.usatoday.com...

New York City is also prone to hurricanes and as we saw with Katrina and numerous other storms, they can cause a lot more damage than earthquakes.

Therefore, your claim that there are no big risks and a history of good conditions in New York is a bit flawed, to say the least. You know what kind of strength is required by a 110 story building with four flat sides to be able to withstand hurricane force winds of 100-150 MPH?

The way you seem to put it, they just threw up the WTC Twin Towers without a care in the world about the potential harsh elements. I don't think that's the way it works.

reply to post by ANOK


If the structure was compromised. which is not an opinion but a fact, then the structure would fall in due time. With heat and fire and very good proof of thermit present and all that, the structure had to come down.


reply to post by Azp420



Perhaps you continue to miss what I said. The item which fell was the compromised structure. The outer structure was torn apart on one side and the inner structure was pretty much gone after the thermite, which again there is proof to being present. In the past 9 years we have deduced that the steel was bending from the jet fuel fire alone. This has been proven. What we were unable to prove was that the size of the steel used would break. It has been proven that smaller sized pieces would break. Add in the thermite and there is no chance the structure is going to stay up. The top part collapses because it's basically held together by the 3 sides of the weaker outer structure at that point. The mass hits the floor bellow. The inner structure is already collapsing from the weight. And the floors cannot support the mass above them. The outer structure stands for a bit and acts like a cone, forcing the mass straight down, then it falls itself. Again not opinion. Simple fact from observation in the video.

What forces are at work? More force down than can be supported by resistant force up. Because once the first break down occurred of the top section. onto the bottom part, it already had more force downward for that initial one-floor movement. And that was sufficient to create enough added force from the impact speed to bring it all down.

That's also why the south tower collapse was so more traumatic and larger. A larger section impacted when the first floor collapsing collapsed.

Technically you would need less explosives for the south tower because it would have a greater mass impact as the top section fell and devastated the parts bellow. Instead we see a larger scale event than the north tower, seemingly in contradiction to the needed explosives.

Why use less explosives on a less damaged building and more explosives on a less stable building. These things simply make no sense.

reply to post by Gorman91

Perhaps you continue to miss what I said.

Perhaps it is the other way around. I've never said that the towers shouldn't have collapsed, yet you've gone off on another tangent and given me a big explanation as to how you think collapse initiated. Initiation is not the smoking gun.

What forces are at work? More force down than can be supported by resistant force up.

I ask what forces you believe are acting on the top section as it impacts the undamaged lower structure and this is your response. Correct, the downwards force acting on the top section is greater than the upwards reactional force provided by the lower structure, hence the top section accelerates. Only you failed to confront what those forces are more specifically. Too painful? I'll help you out.

The only downwards force acting on the top section was its gravitational self weight.

This means the upwards reactional force provided by the lower structure is smaller than the self weight of the top section. When the top section was stationary wasn't the bottom section providing an upwards force equal to the top section self weight? Why is this significant?

And that was sufficient to create enough added force from the impact speed to bring it all down.

Not even sure what you are trying to say here, but speed is not directly proportional to force.

Why use less explosives on a less damaged building and more explosives on a less stable building. These things simply make no sense.

So you're saying they would have defiantly known ahead of time exactly how damaged one tower would be compared with the other due to the plane impacts?

Originally posted by Azp420
So you're saying they would have defiantly known ahead of time exactly how damaged one tower would be compared with the other due to the plane impacts?

Well, they apparently knew exactly where the planes would hit so they knew where to put the "explosives"

reply to post by Azp420


Yea. And you know what disrupted that equilibrium of force? Heat. Steel cannot supply the resistant force if it is bending and breaking from jet fire and thermite. That is what started the collapse.

I am saying that the clouds produced correlate to the impact of the initial collapse event, not explosives.

Yeah right
They found peoples DNA blown in as many as 16 different directions in radiuses of hundreds of yards from the buildings...
That's a sign of collapse all right.

reply to post by Gorman91


Why are you ignoring what I wrote Gorman?

Originally posted by Azp420
I ask what forces you believe are acting on the top section as it impacts the undamaged lower structure and this is your response. Correct, the downwards force acting on the top section is greater than the upwards reactional force provided by the lower structure, hence the top section accelerates. Only you failed to confront what those forces are more specifically. Too painful? I'll help you out.

The only downwards force acting on the top section was its gravitational self weight.

This means the upwards reactional force provided by the lower structure is smaller than the self weight of the top section. When the top section was stationary wasn't the bottom section providing an upwards force equal to the top section self weight? Why is this significant?

Does your theory rely on ignoring that bit of information?

Steel cannot supply the resistant force if it is bending and breaking from jet fire and thermite. That is what started the collapse.

How many times do I have to point out that I'm not arguing that collapse should not have initiated? Perhaps you should read my argument, it actually has some pretty good points. I know you like to go off on these wild tangents however in an attempt to make it appear as though you have an intelligent opinion on the matter.

I am saying that the clouds produced correlate to the impact of the initial collapse event, not explosives.

What?

reply to post by dereks


Just wasn't aware it was so matter-of-fact.

Well given that I am not a structural engineer, and I don't have access to first hand information or data, I am in no position to speculate to the validity of these "1200" engineers and architects. However it is fun to learn things about how many of you think.

reply to post by Danbones


Seeing as fire and explosions destroy DNA...


reply to post by Azp420



No, not the only force. Once motion was started, there was more force that hit the lower section than weight alone.

reply to post by Gorman91

No, not the only force. Once motion was started, there was more force that hit the lower section than weight alone.

Care to elaborate on that and tell us exactly what this force was? We're talking about forces acting on the falling top section. As far as I am aware gravity is the only downwards acting force. I'd love to know what else there is.

reply to post by Azp420


Objects in motion generate more force than stationary objects. A stationary rock on a table does not put as much force into the table as one crashing into the table at 200 mph.

It's quite simple. Once the capacity for the item bellow it loses it's ability to generate that resistant force, the force going down is greater and in turn the item with that downward force moves.

If a rock is stationary on a table and the table is lit aflame, eventually that table will lose the material capacity to generate the resistant force up and the rock will fall through. Now different for the wtc.

Originally posted by Gorman91
reply to post by Azp420

 

Objects in motion generate more force than stationary objects. A stationary rock on a table does not put as much force into the table as one crashing into the table at 200 mph.

This is true but you make one fatal common mistake. You forget Newtons 3rd law, 'for every action there is an equal and opposite reaction'. In other words when objects collide the forces on each object is EQUAL, increasing motion increases forces on BOTH objects equally. So increased force, motion, speed, whatever, changes the forces on BOTH objects, not just the one moving or the one stationary. So increased momentum still causes the object with the least mass to receive the most damage.

It's quite simple.

Yes it is, if you understand it.

If a rock is stationary on a table and the table is lit aflame, eventually that table will lose the material capacity to generate the resistant force up and the rock will fall through. Now different for the wtc.

Your analogy fails because the buildings did not have any extra 'rock' added to them. A better one would be to just leave the table as it is and set it on fire, then see if it suddenly collapses straight down with all four legs telescoping rather than toppling over.

Before using your imagination you have to understand basic physics, otherwise your mind can make up any old tripe.