My friend said that one technique used to counteract the force of an earthquake on tall buildings was to have a moving counterweight at the top that prohibitted extreme swaying. He said he saw an example on the news that worked well. I would like to know if this is a valid practice and, if so, what the proper architectural/engineering term for it would be. Much thanks for any attempted answer!
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Something similar is used to limit the vibration transmitted between stages in a launch vehicle, and to reduce the vibration induced in helicopters by the rotor blades. It's called active vibration control. Typically a computer senses the accelerations being generated by the environment (whether it's rotor blades, movement of the earth, etc) and the control system generates forces that counteract the forces induced by the environment.
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Bob's answer is more likely to save the building The building has a natural vibration period, a pendulum near the top might help, but more likely it would just add cost to the construction. Neil
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Yes, that is a setup in many high buildings.
I think it is called an earthquake damper.
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I think it is called an earthquake damper.
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