Significance of fundamental frequency

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Tom
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Joined: Sun Oct 04, 2020 2:50 pm

Significance of fundamental frequency

Post by Tom »

Dear Admin,

May I know the geological significance of fundamental frequencies (fo) obtained from HVSR analysis. Eg. if I have a fundamental frequency of a given site as 0.8 Hz and a different site with a value of 25 Hz what are the geological implications of these fo values.

Thanks and hope to hear from you.

Tom
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Re: Significance of fundamental frequency

Post by admin »

Hi,

If for both sites the peak is well defined, the site with a frequency of 0.8 Hz is certainly much deeper than the site with 25 Hz. To get an estimation of the respective depths, it would be necessary to get an estimation of the shear wave velocity in the shallow layers. F0=Vs0/(4*H) where H is the thickness of the soft materials (depth to the first major impedance contrast).

Best regards,

Marc
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