It is a very interested question

Dear Shayan,

The section that you referenced is meant for scaling the selected acceleration record to maximum considered earthquake response spectrum. If we assumed that you have a 3 accelerations (2 horizontals [H1,H2] and 1 vertical) for the same event. You need to choose one acceleration in order to do a 2D study.

After you select the acceleration you can find the response spectrum of this acceleration. There is many software do this task and I recommend to use SeismoSingle. There is a free version for academic use.

After you get the response spectrum as values you can take those values into excel sheet and scale it to maximum considered earthquake spectrum for the site that you study.

Another fast and reliable approach can be used through PEER Library. This library include a huge amount of records with a plug-in scaling tool. You need to define your response spectrum and the tool will scale it automatically based on your required period.

Hope this help you enough to scale your records.

All the best,

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This videos will help you a lot

https://www.youtube.com/watch?v=2lC1wMq4c_w&list=PLzBZ3hmMnx1ItfMeO9aGQ5PnC65_TeTBv&index=13

https://www.youtube.com/watch?v=-Wwe4KQvnMk&list=PLzBZ3hmMnx1ItfMeO9aGQ5PnC65_TeTBv&index=14

PEER Library Address

https://ngawest2.berkeley.edu/

SeismoSignal

http://www.seismosoft.com/seismosignal

Dear Mohammed Masmoum

The procedure you just explained is the same as what ASCE 7-10 recommends. ASCE 7-16 explains that for the aim of scaling ground motions, first there should be a maximum direction rotational response spectrum (Rot D100) for each pair of ground motions. Then scaling should be perform according to median of all Rot D100s. I know how to scale ground motions based on what you said, the problem is, it is different from what ASCE 7-16 recommends (there is no separate section for 2D modelling).

Dear Shayan Safaei ,

To answer your question, you can get the maximum rotational spectrum (RotD100) from NGA-West 2 website if you follow this procedure.

More information about this issue can be found in the following article.

Article NGA-West2 Models for Ground Motion Directionality

I hope that will help.

All the best,

Dear Mohammed Masmoum

There are some conceptual problems.

1- Scaling based on maximum directional spectrum seems rational when analyzing 3D nonlinear models, not the 2D ones. In 2D models, we analyze the structure for each component of ground motion pairs separately, So speaking of RotD100 doesn't make sense.

2- PEER scales each pair of ground motion up to MCE spectrum which is so conservative because ASCE07-16 indicates that the average of all ground motion's maximum directional spectrums should be scald up to 90 percent of MCE.

I think for 2D structural models, it is proper to scale each ground motion based on its normal spectrum and there is no need to RotD100 (The same as what ASCE07-10 and FEMA P695 recommends).