On 12/30/12 3:06 PM, Hans Hammarquist wrote:
Anecdote or not. If you push enough current though any conductor it
will "explode". (This is actually use in one type of detonators.)
Oddly, I have personal experience with exploding wires (not EBW
detonators, but in other applications)...
THere's nowhere near enough *energy dissipated* in a lightning strike
through a Ufer ground to do this. The actual stroke is about 100
kJ/meter & the dissipation in the stroke in air is substantially higher
than in a grounding system. To put 100kJ in context, TNT is about 4
MJ/kg. about 110kJ/ounce. So, put an ounce of TNT in a properly
designed hole in some concrete, and you can split it or spall it.
I
don't know how much current required to crack concrete and if a
direct lightning strike can be enough, but I don't think we have to
worry so much about that as such a "super" strike will cause more
harm in other places around the tower hit.
Yes..
I have my present house designed to take a "super" strike. I am using
3/4" copper pipes in all four corners of the house. According to the
engineer, helping with this design, my house is ready for one of
these "super" strikes, observed on occasions. I believe it is a
lightning with a peak current of 300 kA, maybe it was even more.
Anyhow, after three confirmed, direct hits in the house, I feel
relatively sure I did something right.
yes..
The key thing on destruction is the I^2*t (called the action).. Because
that's related to the energy deposited
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