In the final section of this report an energy balance analysis of the collapse of WTC 1
is presented and the energy consumed in crushing concrete on one floor (234 MJ)
compared to other contributions to the energy dissipated by the collapse.
As expected, the plastic strain energy dissipated by the buckling of columns (284 MJ)
is confirmed to be the largest drain on the kinetic energy driving the collapse but clearly
the energy to pulverize the concrete is comparable in magnitude.
However, and more importantly, it is argued that such energy sinks should be summed
over two WTC floors per impact to allow for the simultaneous destruction of the uppermost
floor of the lower, fixed section and the lowest floor of the descending section.
Nevertheless, such a conservative assumption still leads to an energy decrement that
is only a little over one half of the input kinetic energy, thereby assuring a self-sustaining
progressive collapse of WTC 1. By way of a footnote to this report, the pulverization of
concrete by explosive blast is briefly considered and it is shown that, without the help of
gravitational collapse, the degree of concrete pulverization observed during the
destruction of WTC 1 would have required over 600 tonnes of high explosives.
At $1000.00+/-per ton of high explosives, that is inefficient, and any self respecting engineer would concur.
430 thousand tons of concrete, give or take for each tower.
Under gravity free fall, starting at 1700ft, each floor weight at 3900+/- tons would pulverize easily, as observed.
From this:
https://www.911myths.com/WTCONC1.pdf
