In the selection guide the values used for the response spectra are those of the design spectrum, shouldn’t we use the ones of multiple-period MCER spectrum?
Yes. Use MCER instead.
My team is wondering if instead of entering 30 for the number of records collected in the PEER tool (number used in the guide provided), we can directly put 11 directly on the tool, and put these in the proposal with their respective graph. And another question would be if we should scale them with their respective scale factor before placing them in the proposal.
1.) You can put 11 ground motions in the platform. However, usually one would ask the platform for a bigger number and then choose the best 11 based on engineering judgement. 2.) A Figure including the scaled response spectra at the target level and the target spectrum is recommended.
We Selected of at least 11 ground motions representative of GM#2 and GM#2 but I want to ask about should we give detail data? Just is graph suitable? Do we have to use RotD100?
Details are required, along with the figure. Please refer to page 22 of the GROUND MOTION SELECTION GUIDE for further information. Yes, based on Asce 7-22, since you are matching MCEr, then you should use RotD100!
The GM2 that will be used for the shaking table will be an accelerogram scaled to match the spectrum for a specific period range (i.e. 0.05-0.3s) or scaled to match the entire area of the spectrum? Will it be a recorded or an artificial ground motion?
The GM2 response spectrum should be reasonably close to the ASCE specified spectrum in some period range (undisclosed), while it typically shows lower response intensity in the other period ranges. Remember, the ASCE specified response spectrum is an average one for a large number of ground motions. Therefore spectrum for a specific GM can only
Where can i find the response spectra of the GMs that were used in the last edition of SDC – San Francisco 2023? (mentioned in the Design Guide)
The response spectrum are generally not disclosed from the SLC. However if you have the ground motion data, you can use some software or online tool to generate the response spectrum for your reference.
We created (scaled spectra:all record TotD100 graph) but when we write the values to table on NHR3, we find these headings different from the value found in the selection guide report. 1) Recommended Scale Factor 2) Mean Squared Error. Is it a problem?
Headings are different: ground motions guide is a guide. Use engineering judgment and be able to justify your reasoning.
When following the ground motion selection guide, the values resulting from one step are then used as inputs in the next step. Should we be using the values that are shown in the selection guide as inputs in the next step, or the values we get from the various websites? I ask because these are for some reason different. For example, the USGS disaggregation tool, when given the exact parameters shown in the selection guide, produces different results (i.e. distance = 66.85 km, not 50.33 km). Then, when searching through NGA-West2, the selection guide suggests to filter the distance to 50.33 km +/- 20 km = [30.33,70.33] km. Restating the question, should we use this value, or 66.85 km +/- 20 km = [46.85,86.85] km? Thank you!
The ground motion selection guide is provided as reference. Please use the values from the platform for your own selection. If you have trouble finding a suitable ground motion set with these new values, then use the values from the guide and state the reasons why you did not use the exact values.