## Why G coefficients different?

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cemebrahim
Posts: 2
Joined: Tue Oct 02, 2012 12:30 am
Location: azad

### Why G coefficients different?

Hi to all, I want to know which Why G coefficients different?

set accelSeriesx "Series -dt 0.01 -filePath SanFernando1.txt -factor \$g" ;
set accelSeriesx2 "Series -dt 0.01 -filePath 01-SanFernando-PGA=1.226g-dt=0.01-N=4164.txt -factor [expr (1.076/1.160)*\$g*3]" ;
pattern UniformExcitation 2 1 -accel \$accelSeriesx ;
pattern UniformExcitation 3 2 -accel \$accelSeriesx2 ;

thanks.

fmk
Site Admin
Posts: 5866
Joined: Fri Jun 11, 2004 2:33 pm
Location: UC Berkeley
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### Re: Why G coefficients different?

just a scaling thing. ground motions can be scaled differently is user wants them to be, up to user.

cemebrahim
Posts: 2
Joined: Tue Oct 02, 2012 12:30 am
Location: azad

### Re: Why G coefficients different?

Thank you very much professor Mckenna for your prompt response!
set iGMfile "H-E01140 H-e12140" ; # ground-motion filenames, should be different files
set iGMdirection "1 2"; # ground-motion direction
set iGMfact "1.5 0.25"; # ground-motion scaling factor
.
.
.
ReadSMDFile \$inFile \$outFile dt; # call procedure to convert the ground-motion file
set GMfatt [expr \$g*\$GMfact]; # data in input file is in g Unifts -- ACCELERATION TH
set AccelSeries "Series -dt \$dt -filePath \$outFile -factor \$GMfatt"; # time series information
pattern UniformExcitation \$IDloadTag \$GMdirection -accel \$AccelSeries ; # create Unifform excitation
}
But in this model, we see that the coefficient G is horizontal =1.5 and vertical=0.25.
in all of the models said coefficient g is variable.
why?

DuongHoangn
Posts: 4
Joined: Wed Jan 27, 2021 6:08 am

### Re: Why G coefficients different?

fmk wrote:
Mon Apr 08, 2013 12:52 pm
just a scaling thing. ground motions can be scaled differently is user wants them to be, up to user.
dear sir, can you explain this scaling factor, I took the ground motion from ngawest2.berkeley.edu website. and I don't know how to get this scaling factor to fill in the model. When you said ''ground motions can be scaled differently'' , it means that the interval impacts of GM are different which different scaling or something? the GM that I took from that website is not changed, right?

DuongHoangn
Posts: 4
Joined: Wed Jan 27, 2021 6:08 am

### Re: Why G coefficients different?

I'm so confused bcz the result'll be changed when I change the scaling. which the higher scaling factor the model will be collapsed.