It seems to me that the seismic loads are only being applied in the positive direction instead of both the positive and negative direction. Is this the way that RSS typically handles the seismic loads? I understand that load in the opposite direction would essentially inverse these reactions, but I'm just trying to get a deeper understanding of how the program works and addresses the loading. Thank you.
Correct, we handle reversibility through load combinations unless tension-only analysis is considered. See: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/3058/ram-frame---tension-only-faq