11-08-2013, 02:55 PM
(This post was last modified: 11-08-2013, 03:10 PM by Tony Szamboti.)
Albert Doyle Wrote:Lauren Johnson Wrote:[
Tony, you said the initiation of a ROOSD would require five floors of core columns and their support structure to vanish to provide the sufficient force. I believe Jeffrey, said it would require only one floor.
That is helpful.
If I read it correctly Tony said it would take the mass of a 5 storey section to break the static resistance of the intact building below it. What static resistance means is simply the structural strength of the building below in its total state or stasis. When I pointed-out to him that a 12 storey section clearly fell on the rest of the building in the North Tower he failed to give a straight answer.
I said it would take 5 floors falling on one floor to break the connections of the floor to the columns. You are confusing impact of floors with impact of columns. There is a big difference. 12 floors could not fall on one floor. You are not realizing the columns would have prevented that in a natural collapse and they are designed to support many times the story load above them. The columns of the 98th floor, which were supporting 12 stories above them, had enough reserve strength to support about 48 stories with no margin.
You need to separate impact of floors (think floor slabs) from impact of columns in your thinking.