Question

how the resonance frequency of any building or bridge is measured?

Answer 1

depends on th shape n size of the structure

Answer 2

they are just a vibrating bar like tunig fork or ... (suspension bridge) is just like a pendulum.

Answer 3

like a physical pendulum?

Answer 4

a swinging catenary (for suspension bridge)

Answer 5

I assume that a way to measure it would be to emit sounds of different frequencies and measure which frequency makes it vibrate with the highest amplitude.

Answer 6

laser vibrometer..is used to measure low frequencies in building and at bridges