Two options that are recommended for static earthquake loading.
Please keep in mind that AutoPIPE V8i Standard (09.06.xx.xx and lower) only allows up to 5 static earthquake load case, where AutoPIPE Advance and Nuclear allows up to 10 Static earth quake cases.
Please see the following AutoPIPE help section:
Help > Contents> Contents Tab> Bentley> Getting Started> AutoPIPE Standard vs Advanced vs Nuclear
Forum Posting: ASME 31E seismic load calculations