You can combine load cases in a design situation in a Seismic/Mass combination.
In the Standards I tab of the model's Base Data, specify the standard according to which the load cases and thus the masses should be combined.
For some standards, there may be further, special mass combination options. In DIN EN 1998‑1/NA:2021‑07, for example, the coefficient φ for live loads in Categories A through C depends on the position of the loads in the building. A distinction is made between the top full story, including the roof, and other stories. You can make the specifications in the Additional Settings tab of the respective load case in order to consider the load case in the combination.
