Fire weakens steel to collapse SF bridge.

Originally posted by ULTIMA1

Originally posted by esdad71
All this shows is that steel encased in concrete is weakend in a sustained fire. This is a comparison at best but it should be observed since the WTC had inches of concrete, and we all agree the steel was weakened, and not melted.

Funny, its ok to compare a bridge to the towers but not other steel buildings.

I don't see it that way. We're comparing steel to steel, aren't we?

I understand what you are saying and actually that is what I was thinking. But, you are forgetting that the expansion joint IS where they failed. The only explaination is that the thermal expansion was too much for the joint to handle and the two slabs buckled. Here are some more pictures that show this.



In this one, you can clearly see that the expansion joint in the middle of these two slabs has been forced upward. It kinda looks like tectonic plates does it not?




In this one, we can see that both (actually all 3) failures are at the expansion joints.

Originally posted by DazedDave

Originally posted by junglelord
bridge like that collapesed in Montreal last year
exactly
I have never seen a skyscraper fall
I have seen bridges fall.
no fire needed

here is the basic link to the bridge = the towers fallicy

www.infowars.com...

[edit on 1-5-2007 by junglelord]

The bridge that fell in Montreal last year was due to faulty maintenance. Since we have really messed up weather (from very hot to very cold frequently) and extremely cheap and crappy roads, they need to be maintained alot more frequently. They neglected to do so despite huge cracks in the structure and hence it collapsed.

exactaly
so if they are made to withstand earthquakes in california and severe weather and enviromental and salt erosion here and they still fall...no fire and people die...we all agree bridges fall all the time

sky scrapers on fire have only fallen once

You can no more logically compare a bridge collapsing due to fire to a building as you can one building to another. In every situation there's an infinite number of variables that differ in all situations. Using completely different events as evidence to prove something is dishonest.

Any time someone puts forth the "no steel building has collapsed" argument is pushing pseudo-science. It wouldn't hold up academically, it proves nothing. Just as this bridge doesn't disprove anything. It's simply another waste of time and resources.

Even a well written, logical argument comparing the building in Madrid to the WTC's can be "debunked" by someone simply by saying they're different. One sentence writes it off. It reinforces what "truthers" believe and proves nothing to "debunkers". What's the use in preaching to the choir?

This is my new litmus test. If you're a debunker using this bridge as an argument that steel structures can collapse, I don't trust you as much. If your a truther that can't see that a bridge is a structure made of steel and concrete - just like a building and say that you can't compare the two, I don't trust you. Your beliefs are clouding your logic.

This subject is too important for garbage like this to even be brought up.

Originally posted by Griff
I understand what you are saying and actually that is what I was thinking. But, you are forgetting that the expansion joint IS where they failed.

The expansion joint has no impact on the girders strength. It is simply a piece applied to the end of each set of girders to fill the gap during expansion and contraction. What you are seeing in the pictures you posted is one of the expansion joints attached to the end of the girder. The expansion joints are made of two matching pieces. They are not connected in the middle and they do not support any weight, other than a small amout from the cars driving over it.

If you look at the expansion joint you can see where it's attached to the girders behind it. The girders are what was sitting on the column and carrying the load. You could have melted the expansion joints to goo, removed them and replaced them with silly putty, and the bridge would have stayed up. As proof that you don't need an expansion joint to have a bridge, watch this video of a girder installation.

Girder installation movie

The buckling you're seeing is just from the broken piece of roadway when it fell onto the bridge below it.

That support bean DOES NOT LOOK MELTED OR EVEN WARPED TO ME... the vertical one is tilted.

Where is the melting?

And this is from a fire FIVE TIMES AS HOT as at the WTC towers?!?!?!?

Lock the thread... it is toast.

[edit on 1-5-2007 by Pootie]

Here is what a WTC column looks like from a fire 1/5 as hot???

You are ruining your own story here:



According to the official story of 9/11 that bridge column should look like this, or be melted or be VAPORIZED... wait, that was the Pentagon plane... ooh well. All these stories suck.

Ah! I just noticed that the girders (beams) were actually steel instead of concrete. Now it makes more sense. Of course the steel melts or at least sags when you have a 3,000 degree fire burning underneath it.

The overpass made of concrete and asphalt was held up by a lattice of structural steel beams attached to concrete columns.

Steel is known to lose half it's rigidity at 1,000 degrees and melts at 2,750
source

On this bridge the girders don't even touch the column. They rest on a piece of steel that spans the concrete columns. The lower bridge on the other hand appears to have the concrete girders and stayed intact even though it had a truck buring on top of it. The solution was simple once you gathered all the facts.

Silly media. While they said steel and concrete, they fail to mention which part is steel and which part is concrete. That made all the difference.

[edit on 1-5-2007 by dbates]

Originally posted by dbates
The buckling you're seeing is just from the broken piece of roadway when it fell onto the bridge below it.

First of all, I'm not talking about the expansion joint melting anymore and has no relevance to what I'm saying. Also, this is the third time I've said, they failed at the expansion joint due to not enough thermal expansion capacity of the joints. The two slabs expanded and pushed into each other like tectonic plates. Why is this so hard to see? You seem educated enough in expansion joints. The fact that the expansion joint holds minimal loads is irrelavant. The slabs had no where else to go but buckle when they couldn't expand anymore.

I misuderstood what you were saying. You are correct. Also I hadn't seen a good picture of the underside of the bridge and thought the girders were concrete.

Originally posted by DazedDave
I don't see it that way. We're comparing steel to steel, aren't we?

But why is not ok to compare steel buildings to steel buildings ? Evertime i bring up other steel buidlings that have not collapsed the people that believe the official story say i can not use other steel buildings as a comparision.

To reiterate what I'm saying.

Let's assume the spans of the girders are 40 feet. That's 480 in. The coefficient of thermal expansion of carbon steel is 10.8 x 10^-6 in./in. F

So, if we take delta T as 3,000 - 70 (starting temperature) we have 2,930

So, 480 in. x (10.8 x 10^-6)in./in.F x 2930 F = a little over 15 inches. I don't think the expansion joints could accommodate 15 inches of expansion. Also, expansion is not only linear, it's volumetric. Meaning it expands in girth the same as length.

Originally posted by dbates
I misuderstood what you were saying. You are correct. Also I hadn't seen a good picture of the underside of the bridge and thought the girders were concrete.

You were also correct in what you were saying. I think we were just off sinc a little with what each other was trying to get out. I know I'm not always clear on getting my thoughts across.

It's also probably my fault because I did mention the rubber in the expansion joints melting at the beginning of this thread. But, as you pointed out, that would have little bearing on it.

Originally posted by ULTIMA1

Originally posted by DazedDave
I don't see it that way. We're comparing steel to steel, aren't we?

But why is not ok to compare steel buildings to steel buildings ? Evertime i bring up other steel buidlings that have not collapsed the people that believe the official story say i can not use other steel buildings as a comparision.

I'm not architecht or anything, but aren't different buildings built different ways? I seem to remember reading that the WTC had a somewhat unique design structure.

I think the only fair comparasion you can make is with a building that has a similar design. Simply using a steel building is as fair a comparasion as using a steel bridge.

I'm not fighting either side, just trying to provoke discussion.

Originally posted by DazedDave
I'm not architecht or anything, but aren't different buildings built different ways? I seem to remember reading that the WTC had a somewhat unique design structure.

I think the only fair comparasion you can make is with a building that has a similar design. Simply using a steel building is as fair a comparasion as using a steel bridge.

I'm not fighting either side, just trying to provoke discussion.

Well when you look at other steel buildings that have had fires burning longer then the fires in the WTC buildings and had severe structural damage as bad or worse then the WTC buildings but still did not collapse it makes you think.

The WTC buildings have been the only steel buildings to collapse from fire and structural damge in the US in 30 years. What are the odds?

[edit on 1-5-2007 by ULTIMA1]

Originally posted by ULTIMA1

Originally posted by DazedDave
I'm not architecht or anything, but aren't different buildings built different ways? I seem to remember reading that the WTC had a somewhat unique design structure.

I think the only fair comparasion you can make is with a building that has a similar design. Simply using a steel building is as fair a comparasion as using a steel bridge.

I'm not fighting either side, just trying to provoke discussion.

Well when you look at other steel buildings that have had fires burning longer then the fires in the WTC buildings and had severe structural damage as bad or worse then the WTC buildings but still did not collapse it makes you think.

The WTC buildings have been the only steel buildings to collapse from fire and structural damge in the US in 30 years. What are the odds?

[edit on 1-5-2007 by ULTIMA1]

Well to be fair, they did kinda get hit by airplanes.

Originally posted by DazedDave
Well to be fair, they did kinda get hit by airplanes.

But the airplanes did not cause the collapse (please read NIST and FEMA reports). The buildlings had structural damage from the planes. But as stated before and i will state again, their have been buildings with longer burning fires and had suffered severe stuctural damage and did not collapse. Please look at the buildings aroud the towers like buidlings 5 and 6. They were closeer to the towere and suffered more stuctural damage and fires and they did not collapse.

I can show several other steel buildings that had fires burning far longer the the WTC buidlings and had structural damage but did not collapse.

Originally posted by ULTIMA1
But as stated before and i will state again, their have been buildings with longer burning fires and had suffered severe stuctural damage and did not collapse. Please look at the buildings aroud the towers like buidlings 5 and 6. They were closeer to the towere and suffered more stuctural damage and fires and they did not collapse.

I can show several other steel buildings that had fires burning far longer the the WTC buidlings and had structural damage but did not collapse.

So? So what? Those steel buildings don't have the variables that the WTC's did. None of them where as tall and none of them had jumbo jets fly into them, just to name a few. Maybe the contractors that built the WTC's were shoddy and covered it up. As I stated before and it was ignored, you can't compare one building to another, just like you can't compare a bridge to a building. It's not academically sound, it's not even logically sound.

Even if there were explosives in the buildings, this argument does nothing to prove it. Not to anyone that already doesn't believe a controlled demolition brought down the towers anyway.

Originally posted by PistolPete
So? So what? Those steel buildings don't have the variables that the WTC's did. None of them where as tall and none of them had jumbo jets fly into them, just to name a few. Maybe the contractors that built the WTC's were shoddy and covered it up. As I stated before and it was ignored, you can't compare one building to another, just like you can't compare a bridge to a building. It's not academically sound, it's not even logically sound.

But as NIST and FEMA reports state the planes impacts did little structural damage to the towers. Also the the jet fuel (what was left after the intial explosion) burned off quickly so basically the fires in the towers were just office fires.

So actually we can compare other steel building fires to the towers and building 7 (that had no plane hit it)

this just helps " cement " that fire can help cause a collaspe , and did .
in s.f and at the wtc .

[edit on 5-5-2007 by gen.disaray]