Parameters of a structure seismic analysis depend on a seismic code used during calculations of a structure influenced by seismic loads. Select Australian seismic code 1170.4 in the New Case Definition dialog or click Parameters in the Analysis Type dialog.
To perform the seismic analysis according to the rules given in the NSZ 1170.5:2004 code, define the following parameters:
In the lower part of the dialog, the Direction definition and Filters buttons are located.
There is the additional button Base Shear; click it to open the Base shear dialog.
Click Eccentricity Definition to open the Definition of mass eccentricities dialog where you can specify how to account for the eccentricity of a mass in the seismic analysis.
The details concerning this structure analysis method can be found in the mentioned code.