jvpoll wrote:
>    "One would think that adding heavy cross
>     members every 20 floors or so might
>     prevent the entire structure from
>     pancaking like that"
>
>I wonder what the 'load' of oh, say, what? ten
>stories is as it collapses down upon the next
>story ... isn't that **the new load** that
>that the floor space *then* needs to support -
>- the full ten stories that just came down? Not
>to mention the inertial effects that the mass
>of ten stories has gained in ten feet (or more)
>of distance ...
>
>As it was, I am assuming that the vertical support
>steel structural members (both external, along
>the external walls and internal) *failed* on
>one story initially -
>

This ????
+----------------+
|                |
|                |
|     +----+     |
|     |    |     |
|     |    |     |
|     +----+     |
|                |
|                |
+----------------+

or this ????
+-----+----+-----+
| \   |    |   / |
|   \ |    | /   |
+-----+----+-----+
|     |    |     |
|     |    |     |
+-----+----+-----+
|   / |    | \   |
| /   |    |   \ |
+-----+----+-----+

Which is gonna do better? Which is more likely to
have the broken part crash "outwards", sparing
the floors below? Which is more likely to come down
110 stories like an elevator down an empty shaft?

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