: The translational mass of the floor in the global X and Y directions.
ETABS generally "lumps" masses at the floor levels to simplify the analysis into a Multiple Degree of Freedom (MDOF) system. Mass - CSI Knowledge Base etabs mass summary by story
High mass on a soft story (e.g., heavy parking level with open ground floor) is a collapse risk. Identify this in the summary and re-evaluate your stiffness. : The translational mass of the floor in
The total mass of the building is the fundamental variable in the formula (Base Shear = Seismic Coefficient etabs mass summary by story