So it seems you're still wild about collapse down-up theory with inelastic collision,
[url=http://911blogger.com/node/19384]Anders Bjorkman: AE911Truth.org[/url] said:
A smaller part of an isotropic or composite 3-D structure, when dropped on and impacting a greater part of same structure by gravity from above, cannot one-way crush down the greater part of the structure.
In other words, an isotropic(uniformity in all directions) structure A(lower blocks of floors) can not be destroyed by a part C(upper block according to Bazant and Greening's model) (C ≈= 1/10 A) by part C falling on A by gravity alone. Part C either bounces off A or is damaged upon impact with A or is stopped by A with A suffering damage. More simply, Part C will not annihilate part A.
The ridiculous one-way crush down-up theory proposed by Bazant and Greening assumes a rigid upper block. This is so whacky that I don't even think NIST dares to be associated with it. Or do they?