When performing a modal analysis you need to add factors for the seismic load (essentially I/R per ASCE 7) as well as factors for Dynamic Eccentricity (DEC) and Accidental Eccentricity (ECC). My understanding is that DEC is inherent torsion. For an analysis in the positive X direction with positive eccentricity the factors for the seismic load and DEC are both positive (with DEC being 1) and the factor for ECC is positive as well (0.05). For eccentricity in the negative direction the sign for ECC would be negative (-0.05). Is it true that when considering a seismic load in the negative X direction the factors for both the seismic load and DEC are negative? Thanks.
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