T_Szamboti wrote:Heiwa, this paper shows that there was insufficient energy loss in the falling mass to accelerate the masses below to the same velocity it was moving at, while also overcoming structural resistance.
I know. But the author, unknown, treats the initially falling mass - 'the upper block' - as a structure that is not damaged in contact with 'the lower block', which is not correct.
'The real upper block' is in fact weaker than 'the lower block' and would be locally damaged and arrested by 'the lower block' immediately at contact.
But we can evidently replace 'the upper block', 53 m tall, SG 0.2, by a steel plate, 1.35 m thick, SG 7.8, and use it as 'the upper block'. It has the same mass as before but is really solid (or rigid) and will not get damaged when it is dropped on 'the lower block'.
But I would not expect a 1.35 m thick, solid steel plate, mass 33000 tons, SG 7.8, dropped from 3.7 m above the object to crush to be able to crush down a 350 m tall structural assembly of steel columns/concrete floors! I would expect the steel plate to slide off the structure below in the process,e.g. due to unsymmetrical failures in 'the lower block', e.g. one wall failing before the other, etc.. But you are right. The steel plate should decelerate while compacting the lower structure.
Anyway, at the end such an imaginary process, you should find 'the steel plate' undamaged on top of or beside of what remains of 'the lower block'. Any trace of 'the upper block' afterwards?
According Bazant 'the upper block', e.g. the steel plate, will self destroy in a crush up
! Actually, it will bounce in contact with rubble/ground, so at least the final part of the Bazant model is easy to prove wrong, assuming that 'the upper block' is rigid.