Sunday, September 04, 2011

Explosive evidence for the 9/11 building collapse

1 comment:

  1. Architect Richard Gage has produced a masterful piece of propaganda that proves he is still in denial about his own lack of understanding of how the long-span floor systems in the WTC high-rise buildings caused the progressive collapses. The average architect in his group has never heard of, or is apparently unable to fathom the newly discovered failure mechanisms affecting long-span steel floors just coming to light after the NIST investigation which the A & E for 9/11 Truth people apparently believe is just a monstrous cover up. Because they never even heard of these new collapse mechanisms, they make the assumption that the buildings had to be taken down by pre-planted explosives than accuse any people who disagree with them of being in on the conspiracy.

    Such fire-caused failure mechanisms in long-span steel floors include differential expansion between the concrete slab and the steel beams causing failure of the shear studs breaking the composite bond, thermal bowing where the bottom chord of a bar-joist expands faster than the top causing pull-in tensions, restrained expansion in long-span floors causing compression buckling, torsional-buckling where the beam twists out, and significant cooling contraction tension in deflected beams as the fire dies down. All of these mechanisms produce tension on the connections that can tear out the shear connections1 not designed for these lateral forces or pull the columns into buckling. Mr. Gage’s lack of comprehension about how these long-span floors fail is why he comes up with such outlandish ideas that explosives had to be placed on practically all the columns to sever them simultaneously. He has to face up to what actually happened in these buildings and drop his delusional ideas about a vast conspiracy of people from within our own society who would have to have been complicit in such a dastardly deed.

    1 Shear connections are designed to transfer only vertical gravity loads, whereas moment connections are designed ito transfer loads and moments (forces resulting from bending of a beam) induced by both (vertical) gravity and (horizontal) wind loads.