Resonant vibration can be a naturally occuring phenomenon in bridges.

The video displaying the oscillation and eventual collapse of the Tacoma bridges is a well documented example. Another example, this time caused by forced resonance is the Millenium Bridge across the Thames in London.

A variety of methods can be applied to prevent this resonance, with one of the most common being hydraulic dampers. I propose attaching these dampers to turbines for the generation of power. The movement of hydraulic fluid would have to be miniscule otherwise the oscillation would not be supressed, however the weight of a bridge long enough to oscillate would drive tremendous torque.
-- sprogga, Dec 10 2007

Tacoma Narrows Bridge Collape http://youtube.com/watch?v=j-zczJXSxnw
[sprogga, Dec 10 2007]

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