An example of a not controlled tower failure.
https://www.youtube.com/watch?v=ty0CITiZY7E
The guy wires still keep everytihng close to the tower.
Henk PA5KT
Op 4/7/2016 om 4:09 AM schreef Grant Saviers:
It depends on the strength of the tower. A classic brick chimney
almost always breaks into two or more parts. The reason is the top
has to accelerate faster than the bottom for the chimney/tower to stay
straight, i.e. for all parts contact the ground at the same time since
the top has more distance to cover. Since gravity is a uniform
acceleration force, the tower/chimney bends instead as the top lags
behind. For brick chimneys there is little strength in tension and
they come apart. For a steel tower and perhaps reinforced concrete
chimneys, they may be strong enough to only bend or kink. I saw first
hand the result of a 100' steel pipe flagpole failure at its base, and
it did break before hitting the ground. I missed the actual fall by 5
minutes, which was mighty good luck. It bounced off the ground and
meat cleavered two cars almost in half lengthwise.
A different kind of failure is a pancake collapse, which is what
happened in the World Trade Center terrorist attack. If a middle or
bottom floor support fails, the now kinetic energy of the structure
above pancake collapses the entire structure more or less straight
down. So if demolition charges take out say 20' of tower legs, the
whole thing might pancake on itself, since the compression strength of
the tower legs are exceeded by the momentum of the structure above.
Grant KZ1W
On 4/6/2016 16:58 PM, Kathy Bookmiller via TowerTalk wrote:
Probably many of you have already seen this, but this is a HD version
with more views of the tower demolition.
I have one question. I've always heard that when a really tall tower
comes down, it basically collapses onto itself and doesn't fall as
one solid unit extending out the height of the tower. Watching this,
I see many of the towers didn't collapse into one small area but went
down as a full unit.
Kathy
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