Chris,
...Calculations are not necessary....
Boy, if I had a nickel every time I've heard THAT in my career...
... uttered by someone who said it precisely because he didn't know how to do the calculation.
That's the point. NIST lied. Group 7 did not loose lateral support in any direction on any floor. The girders between Group 7 and Groups 6 & 8 provided the lateral support. Groups 6 & 8 would have to fail first.
http://img8.imageshack.us/img8/697/corecolumnnumbercomposi.jpg
.
Sure, I'll walk onto your playground. After spanking you on my home court.
And I'll just ask you a couple of questions, since framing is not my field.
1. You said above that "Group 7 did not loose lateral support in any direction on any floor."
Are you suggesting that Column 69 was not connected to 72? That C68 was not connected to C71? That C67 was not connected to C70?
Is there some secret "framing principle" that would tell you to leave 47 story tall columns UNSUPPORTED in the "east-west" direction?
2. What is the typical aspect ratio (Length:Width:Height) of one of your steel framing jobs? How would that compare to the aspect ratio for the WTC7 building?
Do you think that frames that are really, really, really tall & thin are a little more endangered by loss of lateral support (EVEN "east-west" lateral support) than shorter & wider frames??
3. As Newton noted, if the 40 or so individual girders all pulled
all together down & to the east on those really, really, really tall & thin moment frames, do you think that there is a possibility that they might, oh, I don't know, "feel it"?
4. NIST says that the collapse of WTC1 damaged Column 66. In a framed building, do you think that what anatomists would refer to as "seriously blunt dissection" of a building (aka, a couple thousand tons of debris falling on it), might propagate a teensy bit of damage thru the horizontal girders that attach the damaged column to the immediately adjacent columns?
Or, in framing circles, is dropping a couple thousand tons of debris on a building known to be a "surgically precise" form of disassembly?
Thank you, in advance, for helping me to understand these issues.
Tom
BTW, Chris...
That's the point. NIST lied.
Pompous buffoons recklessly call complete strangers "liars". You seem inordinately comfortable doing that on a rather frequent basis.
If you are going to indulge in such boorish behavior, you might AT LEAST baselessly accuse the RIGHT innocent people.
NIST is clearly not the people that you wish to be casually slandering. Because NIST did NOT provide this sequence that has your panties in such a bunch.
You best start calling the folks at Intel, and ANSYS, and LS-DYNA a "bunch of liars". Because it was their software & hardware (DAMN NWO CPUs !!) that provided all those answers.
NIST simply created the model and hit the "Go" button.
Feel free to resume cavalierly slandering innocent (& competent) people at your (in)discretion.
As you can tell, EVERYONE is moved to tears by your righteous indignation...
LoL.