can you please explain ( maybe in a simple example) the last question
I need to do an initial run, then go back and do a second iteration to apply scaling factors to limit my base shear to the expected value.
I am new to spectral analysis, and I dont understand in the second interation how can I apply the scaling factors and how to get this factors?
You can check the sum of reactions and compare it to the targeted value. This will give you the required scaling factor. Then you can e.g. use the corresponding load factor for given
seismic spectral case.