(Excuse me leftysergeant - but I see you beat me to it so here is some more details for Heiwa)
Some good understanding coming out in your post Heiwa. Lets look at it step by step.
CORRECT We cannot guess - probably both if we stay with your model. If we take the WTC 9/11 model it was not 98 falls on 97. It was "(whatever floor at bottom of top block) PLUS three or so floors of damaged material FALLS on one floor say 97 in your numbers. That MAY still be 50/50 but more likely 70:30 So, reverting to your modeling numbers 98 MAY fail on that first impact against 97 even, in real life WTC 9/11 with up to three floors debris falling in the sandwich. BUT go to the next one - it is two floors plus the impact zone debris falling on one then three floors falling on one; then four floors falling on one. However far that process goes it does not continue as a one for one sacrifce of floors with the "bottom section" winning because it had more floors in its piggy bank...yes - that is what happened for the floors of the outer tube of the office space...I think you are saying what happened correctly. The outer walls simply fell over after the floors separated and at various times after (Actually at various fall distances after the floors fell) Not quite. You need to separate "outer tube columns" from "core columns and beams" The "outer tube columns" simply peeled off in sheets of various sizes just as you say. The core is more complicated for two fundamental reasons. And there is an "x" factor of misclose.
The core could not fall free being surrounded by the doughnut of the falling Top Block or debris. The part falling on the core of the lower section was (mostly) the core of the upper section. The two would variously miss or cone into contact in several ways including:
- Columns collide but end to but end - highly unlikely - if it happened the two would go into overload in axial compression and one or both would buckle;
- Columns strike columns and glance off thus bending somewhat and starting to expose a greater horizontal area;
- Beams (horizontal) land crosswise on other beams - both bend - and both pull inwards the columns they are connected to;
- Columns land on beams; beams land on columns; bits bent by earlier collisions hit something else and bend more; AND
- Some columns of the bottom bit totally miss any falling parts and protrude out of the roof.
..and the whole mess gets more complicated and continues falling accumulating more debris at each stage...not new - I first published on another forum about 16 months back and others have said similar. ...the "6 moving floors" seems wrong - far too high by my estimation BUT, like all these factors it is self balancing - more later if needed.FUNDAMENTALLY WRONG we are modelling the strength of one floor connection with a factor of safety (accepting your figures) of 10 for static or 6 floors for dynamic (whatever that means) - The FOS for columns means 3 times tghe COLUMNBS designed losd which is ~10 or ~20 storeys of total structure - far stringer than one floors FLOOR LOAD ONLY, So you have an order of magnitude error of logic there.
...they fall apart somewhere in the overall scheme but exactly wher doesnt matter nor does it matter if they remain mostly intedgral till the Top Block lands at the botton. The falling mass is the same whete vstill integral as a top block or separated into components.
If I may quote an expert:
... well back into cloud cuckoo land and models not analogous to WTC 9/!! - I will leave that sidetrack alone.
