*.HV file from HV tool

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riccardo
Posts: 34
Joined: Fri Aug 06, 2010 4:37 pm
Location: Pisa

*.HV file from HV tool

Postby riccardo » Wed Nov 09, 2011 12:23 pm

good morning
I have some problem with HVSR tool.
I try to define the SESAME criteria for a reliable H/V curve, using the *.HV and *.log file in output from the H/V tool.

*.HV file is made with some #line that define the f0 from window, f0 from average, f0 peak amplitude and , I think, the standard deviation from "f0 from window, i.e.

# GEOPSY output version 1.1
# Number of windows = 71
# f0 from average 1.18027
# Number of windows for f0 = 71
# f0 from windows 1.17592 1.05407 1.29777
# Peak amplitude 2.98443# Frequency Average Min Max
0.5 2.45394 1.45698 4.13309
0.517476 2.38562 1.41309 4.02747
0.535563 2.32519 1.4446 3.74257
0.554283 2.21936 1.41466 3.48179
0.573656 2.16854 1.45623 3.22929


1) which is the difference between "f0 from average" and "f0 from window"?

2) there is a little error in the HV file, the #Frequency line isn't separate from the peak amplitude line by "end line" (^p), so the import in excel is a little bit more complicate (but it is a very little problem).

3) the number after "f0 from window" are average pick, av. - stdev, av. + stdev?

4) column min and column Max are the av.- stdev and av.+ stdev?

Someone can you help me?

admin
Site Admin
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Joined: Mon Aug 13, 2007 11:48 am
Location: ISTerre
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Re: *.HV file from HV tool

Postby admin » Wed Nov 09, 2011 2:41 pm

1) which is the difference between "f0 from average" and "f0 from window"?

  • f0 from average is computed by scanning the average curve and identifying the frequency at which the maximum amplitude occurs.
  • f0 from window is computed differently. The scan is run on each individual curve (corresponding to one window). Several peak values are then extracted. From this population an average and a standard deviation is assessed.

2) there is a little error in the HV file, the #Frequency line isn't separate from the peak amplitude line by "end line" (^p), so the import in excel is a little bit more complicate (but it is a very little problem).


Thanks for report, now fixed for future releases

3) the number after "f0 from window" are average pick, av. - stdev, av. + stdev?


Yes, it is

4) column min and column Max are the av.- stdev and av.+ stdev?


No, it is av/stddev and av*stddev. Amplitude statistics are computed on a log scale or in other words it is a geometrical average.

riccardo
Posts: 34
Joined: Fri Aug 06, 2010 4:37 pm
Location: Pisa

Re: *.HV file from HV tool

Postby riccardo » Wed Nov 09, 2011 2:52 pm

thank you,

Now I understand what does it mean from SESAME 3rd poit of reliability
(σ A (f) = "standard deviation" of A H/V (f), σ A (f) is the factor by which the mean A H/V (f) curve should be multiplied or divided )

I try to use this information for excel spreadsheet

Riccardo

riccardo
Posts: 34
Joined: Fri Aug 06, 2010 4:37 pm
Location: Pisa

Re: *.HV file from HV tool

Postby riccardo » Sat Oct 12, 2013 11:21 am

Good morning Mark

for the SESAME criteria which f0 I have to use?
f0 from window or f0 from average?

I ask this because I try to create a spreadsheat with calc for the SESAME criteria ... but
in the *.hv txt file there are the data from average h/v curve
and if i look for f0/2 - 2f0 or f0/4 4f0 ranges I study the average curve and I can't find the f0 from window that is the f0 of the site.

differences betwen two f0 is minimal ... but !

what is correct to do?

bcosenza
Posts: 1
Joined: Tue May 12, 2015 7:07 pm

Re: *.HV file from HV tool

Postby bcosenza » Tue May 12, 2015 9:00 pm

I have the same doubt, about which is the right frequency to use, not only to check the SESAME criteria, but to report as the fundamental frequency of the soil one's studying.

I also would like to know if there is an upper limit to the width of the windows. I read the SESAME guidelines and the minimal width is quite well defined. We suspect our target frequency is between 0.8 and 1 Hz, and we are using 60 second windows over 30 min long registers, could this be a problem?

It is a recommendation to measure as far away from buildings as possible. We have sets of measures on fields but we also have one set of measures that taken inside a building. This measures exhibit a peak displaced to the right by more or less 1.5 Hz. Is the frequency obtained inside the building reliable or should we asume we're not measuring the soil response, but the response of the structure?

Thank you very much for your help!


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