I tried to solve it this way, I attach the file below.

I have another question: is it possible to create a single folder that collects all these .out files and has a specific name, as in the recorder?
If the shear wave velocity of the bedrock is 800 m/s and the frequency of the input motion is 0,6 Hz (I have to use the peak frequency, don't I?) lambda should be about 1,3 km , isn't it?Given the material properties and the input frequency, the wavelength is about 6 km!