Re: ~ Ping Rob K. ~

On Sep 25, 6:18 pm, Henry <9...@insidejob.gov> wrote:
> Hi Rob. We had this exchange a while back.

>
> You never did explain how your falling blocks and sticks
> "prove" that a tall building won't topple sideways if
> supports on only one side are destroyed.

Again, falling straight down is a common failure
mode in quakes. More common than toppling over.

You apparantly feel this can only happen if all
sides fail "simultaneously". This is incorrect.

An initial failure on one side transfers additional
load to other supports, which then fail in rapid
succession, transferring the load to adjacent
supports etc.

Think of a rapid chain reaction. There is no
portion of the structure strong enough to form
a hinge for the upper part of the building to pivot on,
so even if a failure occurs first on one side, it
propogates rapidly through the entire set of
vertical supports, causing the building to drop
more or less straight down.

This is the second time I've answered the same
question. Hope you got it this time.