Merged Core-led collapse and explosive demolition

[Clayton Moore]

Intact columns means that they weren't severed. It means that the estimated 85% remaining intact columns did not have any ends dangling in the air, waiting to slip by their counterparts below. It means that 85% of the column structure was intact. Do you know what intact means? It means continuous. Connecting upper portion to lower. This means that the impact from the upper portion slumping onto the lower would be translated through the 85% remaining continuous, intact, column structure. That means you would have to see a deceleration as the upper portion pushes through those intact columns.

A one-hour office fire would not suddenly sever the 85% intact columns either. Nor would they suddenly bend like wet noodles. But even if they did suddenly bend like wet noodles, you would still have to see a deceleration, as there is still 75 - 90 storeys of intact structural framing below the slumping portion.

Exactly.

Everything they, the trusters, spew is disinformation. The mainstream media says nothing because they wouldn't be able back up the lies if people read them in the paper, magazines, or TV.

Here on the web the trusters swarm at will to protect their neocon overlords.

 

[Dave Rogers]

Exactly.

Everything they, the trusters, spew is disinformation. The mainstream media says nothing because they wouldn't be able back up the lies if people read them in the paper, magazines, or TV.

Here on the web the trusters swarm at will to protect their neocon overlords.

Well bleated.

Dave

 

[TruthersLie]

It's the strangest thing; I knew, before I even read the post you quoted, that your response was a straw man. Because it was said in the patronizing tone you use when you employ them.

Those qualifiers are vital, yet you seem to have omitted them.

That is because he doesn't understand qualifiers...

Words like.
about
essentially vs actually

or prepositions like "into vs onto"

so can you really hold his not understanding qualifiers either.

 

[000063]

Jus' wanted to call him on the straw man.

 

[ergo]

Those qualifiers are vital, yet you seem to have omitted them.

You don't appear to understand what's being discussed.

 

[000063]

You don't appear to understand what's being discussed.

You omitted vital qualifiers from the sentence. The post you quoted doesn't say "prevent column-on-column impacts", but "any significant numbers of column-on-column impacts from occurring simultaneously."

I suppose you're going to keep dodging the fact that you quote-mined by saying you were referring to "debunkers in general", which is useless for debunking that specific post.

 

[ergo]

Instead of highlighting words that are irrelevant to the thesis you claim to defend, why don't you explain 1) how one degree of tilt is "sufficient to prevent any significant numbers of [simultaneous] column-on-column impacts" in columns 85% of which are already continuous, 2) what is this imagined time lag if they are not occurring simultaneously, and 3) how would this allow the upper block to travel smoothly through the lower intact structure (at the rate of 2/3 g)? Thanks.

 

[000063]

Instead of highlighting words that are irrelevant to the thesis you claim to defend,

They're not. They are vital to the claim made, and you just keep dismissing them, claiming they're "irrelevant", without explaining why.

You either quote-mined, or deliberately misunderstood.

 

[aggle-rithm]

Instead of highlighting words that are irrelevant to the thesis you claim to defend, why don't you explain 1) how one degree of tilt is "sufficient to prevent any significant numbers of [simultaneous] column-on-column impacts" in columns 85% of which are already continuous, 2) what is this imagined time lag if they are not occurring simultaneously,

You're shifting the burden of proof here. If you want to claim that something should have happened other than what was observed, you have to know two numbers:

1. The momentum of the falling block
2. The expected resistence of one set of columns falling on another

Just knowing one of these numbers isn't enough, and you don't even have that.

and 3) how would this allow the upper block to travel smoothly through the lower intact structure (at the rate of 2/3 g)? Thanks

If momentum beats resistence, then momentum wins. If momentum beats resistence by a significant margin, then you won't observe much resistence. Just like you don't observe much resistence when a 250 lb running back hits a 180 lb cornerback at full speed.

Based on observations, I would say that momentum beat resistence by a significant margin. But I haven't done the calculations. Have you?

 

[ergo]

If momentum beats resistence, then momentum wins.

Yes, very good. That's the issue under discussion. How does momentum build while the upper portion of the building crushes through the impact zone which still has 85% of its core and perimeter columns intact?

And,

How would this allow the upper block to travel smoothly through the rest of the lower intact structure (at the rate of 2/3 g)?

If momentum beats resistence by a significant margin, then you won't observe much resistence. Just like you don't observe much resistence when a 250 lb running back hits a 180 lb cornerback at full speed.

Yes, very good. Except you have the analogy backwards. Even with your example, though, you would still see a deceleration, wouldn't you?

 

[beachnut]

Yes, very good. That's the issue under discussion. How does momentum build while the upper portion of the building crushes through the impact zone which still has 85% of its core and perimeter columns intact?

And,

How would this allow the upper block to travel smoothly through the rest of the lower intact structure (at the rate of 2/3 g)?



Yes, very good. Except you have the analogy backwards. Even with your example, though, you would still see a deceleration, wouldn't you?

Have you done the math for the collapse? The WTC collapse took longer than free-fall. Please present your numbers to support your claim.

 

[Grizzly Bear]

Ergo needs to read this: http://www.beamchek.com/loadbook/startbook.html

You can't talk about a structure's behavior in absolute terms of "number of columns intact."

For example you might be able to remove 1/3 of the total columns is some arbitrary structure if you did so in a manner that kept the load distribution uniform amongst the remaining structure. But it won't work the same if you remove the same quantity unevenly because it introduces eccentricity to the load that the structure below needs to support.

Same if you have a load that isn't being given a direct path to the ground. In other words the excuse that something can't "fail" solely because a certain [absolute] percentage of columns are "intact" is ludicrously stupid because the stability of a structural assembly is determined by several factors, not one. It's hilarious when people like ergo try to arrogantly tell people who know more about the topics than he does that they're wrong while displaying the very incompetence he's accusing others of.

No the link isn't based on steel structures but the basics are applicable. A floor has to transfer loads to the columns, the columns have to support themselves and the floor. At the end of the "line" the loads have to be transferred and dispersed in the foundation and the ground. I think I had this exchange with ergo before I put him on ignore a few months ago. He thinks these engineering terms are fabricated.

Example Diagram:

 

[ergo]

Holy generic non-answer with an unrelated diagram showing self-evident load distributions, Batman.

I won't yet assume that this question is actually stumping the bedunkers here, but it does seem to be one they consistently fail on. For obvious reasons.

Surely you folks can do better bee-flakery than this? Entertain us!

 

[Grizzly Bear]

I won't yet assume that this question...

That "irrelevant diagram" tells you how a building supports itself. It visualizes how loads are transferred from floor, to beam, to column, to foundation, to ground. You should "theoretically" be able to read it and visualize what happens when you "remove" a certain "percentage of columns" from an assembly. If the point flies over your head at this point then that's not a good sign for you.

Surely you folks can do better <snip>

Here, let's take an example of your work:

Intact columns means that they weren't severed. It means that the estimated 85% remaining intact columns did not have any ends dangling in the air, waiting to slip by their counterparts below. It means that 85% of the column structure was intact. Do you know what intact means?

Here you describe the strength of a building in absolute terms; This one sentence tells us plenty; it is the kind made by people who are complete engineering novices, who refuse to study would try to use in a discussion of structural performance. Eccentric loading, creep, load path, moment are terms that you probably haven't taken the time to look up.You've been too busy trying to insult your peers rather than listen. So the question is: how do we take your "85% intact" posts seriously if you're incapable of demonstrating the engineering merits of your own claims?

A one-hour office fire would not suddenly sever the 85% intact columns either. Nor would they suddenly bend like wet noodles.

With this sentence most people posting in this thread can immediately point out that you've never seen or even heard of a time/temperature curve. These have existed for years as a part of long accumulated study of material properties in building construction, and having put yourself into an engineering topic you ware responsible for having looked at it before critiquing your peers. What's you're excuse for that?

Education time:
Steel doesn't lose it's strength "simultaneously or immediately because of fire; it loses it over a period of time as it gets heated. The reduction in strength lowers the critical failure threshold, and induces a behavior called creep which introduces instability in the structure. That is what causes it to fail at collapse initiation.

In a structural system the failure of one column means that the loads it carried have to be supported by an adjacent column, and so on; reduce the load carrying capacity of enough columns in the assembly, and you increase the eccentricity of the load until it becomes unstable. Hence, every post you make claiming that the building can't have collapsed because it was "85% intact" is a statement born of ignorance.

It means continuous. Connecting upper portion to lower. This means that the impact from the upper portion slumping onto the lower would be translated through the 85% remaining continuous, intact, column structure

By this small paragraph most of us can tell one thing:

showing self-evident load distributions

It apparently isn't so self-evident to you if you can't visualize it for the towers.

Entertain us!

That's a tough call bud.. Real science isn't always entertaining. Sometimes it means writing long, detailed explanations that certain uninterested people will usually write off with flimsy 1 to 3-liner dismissals.

 

[ozeco41]

... Hence, every post you make claiming that the building can't have collapsed because it was "85% intact" is a statement born of ignorance.....

Over the years of explaining some basics of structural engineering to truthers I have used simplified models as examples. So a building with three rows of columns - Row "A" row "B" and row "C". The loads in rows "A" and "C" say 100 and the load in row "B" say 200.


______############
______Higher Levels
______##of Building#
______############
______|_____|_____|
______|_____|_____|
______|_____|_____|
______|_____|_____|
______|_____|_____|

______A____B____C
_____100|__200__100|

Now knock out 33% of the columns - remove all row "C"

What are the loads now in "A" and "B"?

..... to first order approximation will illustrate the key point.

So, in the sort of language ergo has been using we have 66.67% of columns intact. 33.33% removed. What happens to the load in row "B"



Answers later for obvious reasons.

 

[aggle-rithm]

Yes, very good. That's the issue under discussion. How does momentum build while the upper portion of the building crushes through the impact zone which still has 85% of its core and perimeter columns intact?

And,

How would this allow the upper block to travel smoothly through the rest of the lower intact structure (at the rate of 2/3 g)?

Very simple: The building was not designed to accommodate independent movement of any floors. It was designed to handle a static load.

Yes, very good. Except you have the analogy backwards.

Actually, I have it dead on. What I'm describing is a large mass in motion, carrying a huge amount of momentum, colliding with something that is not designed to stop it effectively.

Even with your example, though, you would still see a deceleration, wouldn't you?

At best you would see an decrease in acceleration. But it could be so small as to be unnoticeable.

The greater the discrepency between momentum and resistance, the less you will see resistance. In order to predict whether you would see deceleration, you would have to know both the momentum and the resistance. Your problem is that you don't know either number.

 

[aggle-rithm]

I won't yet assume that this question is actually stumping the bedunkers here, but it does seem to be one they consistently fail on. For obvious reasons.

There is no shame in failing to make someone understand something that he steadfastly refuses to understand.

 

[Oystein]

Over the years of explaining some basics of structural engineering to truthers I have used simplified models as examples. So a building with three rows of columns - Row "A" row "B" and row "C". The loads in rows "A" and "C" say 100 and the load in row "B" say 200.


______############
______Higher Levels
______##of Building#
______############
______|_____|_____|
______|_____|_____|
______|_____|_____|
______|_____|_____|
______|_____|_____|

______A____B____C
_____100|__200__100|

Now knock out 33% of the columns - remove all row "C"

What are the loads now in "A" and "B"?

..... to first order approximation will illustrate the key point.

So, in the sort of language ergo has been using we have 66.67% of columns intact. 33.33% removed. What happens to the load in row "B"



Answers later for obvious reasons.

Teacher, I know it I know it! May I, pleeeeaaase? *snips finger excitedly
*

ETA: by the way, you knock out 33% of the columns, but only 25% of the load bearing capacity, assuming that all columns have the same "safety factor". Maybe ergo will pick up this hint when he does his calculation

 

[000063]

Education time:
Steel doesn't lose it's strength "simultaneously or immediately because of fire; it loses it over a period of time as it gets heated. The reduction in strength lowers the critical failure threshold, and induces a behavior called creep which introduces instability in the structure. That is what causes it to fail at collapse initiation.

In a structural system the failure of one column means that the loads it carried have to be supported by an adjacent column, and so on; reduce the load carrying capacity of enough columns in the assembly, and you increase the eccentricity of the load until it becomes unstable. Hence, every post you make claiming that the building can't have collapsed because it was "85% intact" is a statement born of ignorance.

What I find amazing is that Truthers refuse to accept that a building is closer to Jenga than it is to building blocks.

Or cardboard boxes, in Gage's case.

 

[dafydd]

Instead of highlighting words that are irrelevant to the thesis you claim to defend, why don't you explain 1) how one degree of tilt is "sufficient to prevent any significant numbers of [simultaneous] column-on-column impacts" in columns 85% of which are already continuous, 2) what is this imagined time lag if they are not occurring simultaneously, and 3) how would this allow the upper block to travel smoothly through the lower intact structure (at the rate of 2/3 g)? Thanks.

Where did you study engineering?