stateofgrace
2nd April 2007, 05:06 AM
I am arguing with a couple of truthers on another forum about the structural integrity of the towers prior to the collapse.
My argument, to me anyway seems pretty simple; as each plane slammed into the buildings the external columns were seriously compromised. This damage, along with fires led to the start of the collapse, i.e. through the floors sagging, buckling the external columns and eventually failing.
Of course the truthers refuse to accept my explanation and are arguing that the damage to each building was only slight. They are arguing that only between 15 and 20 percent of the supporting structure was taken out and thus what remained should have easily supported the weight above. The argument then goes that the fires had too much work to do in such a short time to start the collapse.
Basically this is the argument being put forward by the truthers
Check out FEMA chapter 2, it has detailed info on the damages to the perimeter columns by the impacts in both towers. You'll find less than 15% in either building was knocked out, just on the impacted floors.
Then check out NIST simulations of the damage sustained to the core. They even changed a plane's trajectory to get the most damage they possibly could, and only got something like 7 columns severed out of ~50, and a slightly larger number that sustained anywhere from major damage, to a scratch. The rest were perfectly fine.
Let's assume the total equivalent redundancy of a given floor is at least 200% (more than reasonable -- overshooting your target loads by a factor of 2, or 200%, is common for CONVENTIONAL construction; skyscrapers and experimental structures tend to have much greater safety factors, at least ~5).
Even in that bare minimum of column redundancy for safety reasons, the structures were in no danger of collapse from the plane impacts alone. A lot was left for the fire to do, and so much catastrophic failure from fire is completely unprecedented
Can anybody help me out here and point towards a study or the part in NIST's report that addresses this.
Also I know there are photographs of the bowing prior to collapse and the core after the collapse, could somebody post them please.
Thanks in advance..
My argument, to me anyway seems pretty simple; as each plane slammed into the buildings the external columns were seriously compromised. This damage, along with fires led to the start of the collapse, i.e. through the floors sagging, buckling the external columns and eventually failing.
Of course the truthers refuse to accept my explanation and are arguing that the damage to each building was only slight. They are arguing that only between 15 and 20 percent of the supporting structure was taken out and thus what remained should have easily supported the weight above. The argument then goes that the fires had too much work to do in such a short time to start the collapse.
Basically this is the argument being put forward by the truthers
Check out FEMA chapter 2, it has detailed info on the damages to the perimeter columns by the impacts in both towers. You'll find less than 15% in either building was knocked out, just on the impacted floors.
Then check out NIST simulations of the damage sustained to the core. They even changed a plane's trajectory to get the most damage they possibly could, and only got something like 7 columns severed out of ~50, and a slightly larger number that sustained anywhere from major damage, to a scratch. The rest were perfectly fine.
Let's assume the total equivalent redundancy of a given floor is at least 200% (more than reasonable -- overshooting your target loads by a factor of 2, or 200%, is common for CONVENTIONAL construction; skyscrapers and experimental structures tend to have much greater safety factors, at least ~5).
Even in that bare minimum of column redundancy for safety reasons, the structures were in no danger of collapse from the plane impacts alone. A lot was left for the fire to do, and so much catastrophic failure from fire is completely unprecedented
Can anybody help me out here and point towards a study or the part in NIST's report that addresses this.
Also I know there are photographs of the bowing prior to collapse and the core after the collapse, could somebody post them please.
Thanks in advance..